DESCRIPTION
Title of Invention
DYE ADSORPTION APPARATUS AND DYE ADSORPTION METHOD
Technical Field
[0001]
The present invention relates to a dye adsorption apparatus and a dye
adsorption method for adsorbing dye into a porous semiconductor layer formed on a
surface to be treated ("treated surface") of a substrate.
Background
[0002]
Recently, a dye sensitization solar cell has been considered as promising as a
future inexpensive solar cell. As illustrated in FIG. 20, a dye sensitization solar cell
includes, as a basic structure, a porous semiconductor layer 204 impregnated with a
sensitizing dye and an electrolyte layer 206 between a transparent electrode (negative
electrode) 200 and a counter electrode (positive electrode) 202.
[0003]
Here, the semiconductor layer 204 is divided into a plurality of cells together
with the transparent electrode 200, the electrolyte layer 206, and the counter electrode
202, and formed on a transparent substrate 208 in which the transparent electrode 200 is
interposed between the semiconductor layer 204 and the transparent substrate 208. The
rear surface side of the counter electrode 202 is covered by a counter substrate 210. The
transparent electrode 200 of each cell is electrically connected with a neighboring

counter electrode 202 and the plurality of cells are electrically connected with each
other either in series or in parallel in an entire module.
[0004]
In the dye sensitization solar cell configured as described above, when visible
light is illuminated from the rear side of the transparent substrate 208, the dye
impregnated in the semiconductor layer 204 is excited to emit electrons. The emitted
electrons are guided to the transparent electrode 200 through the semiconductor layer
204 and then emitted to the outside. The emitted electrons return to the counter
electrode 202 via an external circuit (not illustrated) and are received in the dye in the
semiconductor layer 204 again via the ions in the electrolyte layer 206. In this manner,
optical energy is immediately converted into electric power which is in turn output.
[0005] In a process of fabricating such a dye sensitization solar cell, a method of
immersing the porous semiconductor layer 204 formed on the transparent substrate 208
in a dye solution so as to adsorb sensitizing dye into the porous semiconductor layer 204
has been employed in the related art.
Prior Art Document
Patent Document
[0006]
Patent Document 1: Japanese Patent Laid-Open Publication No. 2006-244954
Disclosure of the Invention
Problem to Be Solved by the Invention
[0007]
The above-described immersing method requires at least scores of hours in the

dye adsorption processing which may vary depending on the types of dye and thus,
becomes the cause of rate-determining of tact of the entire steps in the process of
fabricating a dye sensitization solar cell and decreasing manufacturing efficiency. In
connection with this problem, it may be considered to operate a plurality of immersion
type dye adsorption devices in parallel which requires at least scores of dye adsorption
devices to be prepared and thus, is not practical.
[0008]
The present invention has been made to solve the problems of the related art as
described above and provides a dye adsorption apparatus and a dye adsorption method
capable of significantly reducing the amount of processing time in a step of adsorbing
dye into a porous semiconductor layer formed on a treated surface of a substrate.
Means to Solve the Problems
[0009]
The dye adsorption in a first viewpoint of the present invention is a dye
adsorption apparatus of adsorbing dye into a porous semiconductor layer formed on a
treated surface of a substrate. The dye adsorption apparatus includes: a boat configured
to detachably hold a plurality of substrates which are arranged in a row such that the
treated surfaces of the substrates face horizontally; a processing tank configured to
accommodate the boat and the plurality of substrates held in the boat to be capable of
going in and out of the processing tank through a top opening; a top cover configured to
close the top opening of the processing tank; a first transport unit configured to
transport the boat into and out of the processing tank; a dye solution supply unit
configured to supply a dye solution formed by solving the dye in a solvent into the
processing tank to such an extent that the plurality of substrates held in the boat are

sunk in the dye solution within the processing tank; and a flow control unit configured
to control a flow of the dye solution within the processing tank during a dye adsorption
processing.
[0010]
In the dye adsorption apparatus of the first viewpoint, a batch type dye
adsorption processing is performed for a plurality of substrates in the processing tank.
During the processing, a flow of dye solution is formed within the processing tank in a
state where the top opening of the processing tank is closed by the top cover and the
treated surfaces of the substrates are exposed to the flow of the dye solution of high
pressure. Thus, aggregation or cohesion of dye is hardly caused on a surface layer
portion of the porous semiconductor layer on the treated surface of each of the
substrates, the dye efficiently penetrates into the inside of the porous semiconductor
layer, and thus, the dye adsorption into the porous semiconductor layer may proceed at
high speed.
[0011]
According to an aspect of the present invention, the processing tank is provided
with at least one first port and at least one second port, the dye solution supply unit
supplies the dye solution to the processing tank using at least one of the first port and
the second port, and the flow control unit controls the flow of the dye solution using the
first port and the second port. In such a case, the flow control unit which may be
properly employed is a type that circulates the dye solution between the inside and
outside of the processing tank, or a type that controls the flow of the dye solution while
substituting old dye solution with new dye solution within the processing tank using the
first port and the second port. Further, it is also possible that the dye solution supply
unit substitutes old dye solution to new dye solution within the processing tank using

the first port and the second port.
[0012]
In an additional aspect of the present invention, the processing tank is further
provided with a third port for use in discharging the dye solution, the dye solution
supply unit substitutes old dye solution with new dye solution within the processing
tank using at least one of the first port and the second port, and the third port, and the
flow control unit controls the flow of the dye solution while substituting old dye
solution with new dye solution within the processing tank using at least one of the first
port and the second port and the third port. In such a case, the flow control unit which
may be employed is a type that, during the dye adsorption processing, switches or varies
the flow direction of the dye solution, a type that, during the dye adsorption processing,
varies the flow rate of the dye solution, or a type that, during the dye adsorption
processing, the flow control unit varies the pressure within the processing tank.
[0013]
In an additional aspect of the present invention, a substrate support unit
configured to contact with and support the rear surface of each of the substrates
independently from the boat is provided within the processing tank.
[0014]
In a preferred aspect, the substrate support unit includes a plurality of support
members which are arranged in a row with a spacing corresponding to that of the
plurality of substrates arranged in a row and held on the boat, and provided in the
processing tank, and each support member may contact with the rear surface of a
substrate corresponding to the support member by a rod-shaped or plate-shaped body
protrusion which extends upward from the bottom of the processing tank.
[0015]

In an additional aspect, the substrate support unit includes a plurality of support
members which are arranged in a row with a spacing corresponding to that of the
plurality of substrates arranged in a row and held on the boat, and provided on the top
cover, and each support member may be contacted with the rear surface of a substrate
corresponding to the support member by a rod-shaped or plate-shaped body protrusion
which extends downward from the bottom surface of the top cover.
[0016]
Since the plurality of substrates which are subject to a batch type dye
adsorption processing in the processing tank are supported by the support members
provided in the processing tank and/or on the top cover on the rear surfaces thereof, the
substrates are rarely flexed or inclined by the pressure applied in the flow of the dye
solution. Thus, the damage or deformation of the substrates may be avoided. In
addition, when the protrusions of the support members are contacted with the rear
surfaces of the substrate, the contact type may be plane contact, line contact or point
contact. With any contact type, the treated surfaces of the substrates do not undergo any
influences.
[0017]
In addition, as described above, the protrusions of the support members may
maintain the posture of the substrates stably within the processing tank. Further, the
protrusions of the support members may suppress the flow of the dye solution along the
rear surfaces of the substrates, and as reflective effects thereof, the protrusions may
facilitate the flow of the solution along the front surfaces (treated surfaces) of the
substrates and further enhance the dye adsorption efficiency.
[0018]
Each of the support members which may be employed is a type that contacts

with and supports one substrate. Alternatively, in order to increase the space efficiency
within the processing tank, a configuration may be properly employed in which a
plurality of substrates are arranged in a row on the boat such that the treated surfaces of
each pair of adjacent substrates are directed in the opposite directions and each of the
support members may contact with and support adjacent substrates of the pair.
[0019]
In an additional aspect of the present invention, a flow suppressing section is
provided to suppress the flow of the dye solution along the rear surface of each of the
substrates within the processing tank. Preferably, the flow suppressing section includes
a plurality of flow suppressing members which are arranged in a row with a spacing
corresponding to that of the plurality of substrates arranged in a row and held on the
boat, and provided in the processing tank, and each flow suppressing member
suppresses the flow of the dye solution along the rear surface of a substrate
corresponding to the flow suppressing member.
[0020]
According to an aspect of the present invention, the first transport unit includes
an arm detachably coupled to the boat, and the arm breaks away from the arm while the
boat is being accommodated in the processing tank together with the plurality of
substrates for a dye adsorption processing. When the boat is transported in the outside
of the processing tank, or transported into or out of the processing tank, the arm is
coupled to the boat.
[0021]
According to an additional aspect, the first transport unit includes an arm
integrally coupled to the boat and the top cover is fixed to the arm. The top cover closes
the top opening of the processing tank the arm while the boat is being accommodated in

the processing tank together with the plurality of substrates for the dye adsorption
processing. In addition, when the plurality of substrates are loaded on or unloaded from
the boat in the outside of the processing tank, the top cover fastening unit is released
and the top cover is retracted on the arm or separated from the top cover.
[0022]
A dye adsorption apparatus of a second viewpoint of the present invention is a
dye adsorption apparatus of adsorbing a dye into a porous semiconductor layer formed
on a treated surface of a substrate. The dye adsorption apparatus includes: a processing
tank configured to accommodate a plurality of substrates which are arranged in a row
such that the treated surfaces thereof are parallel to each other; a top cover configured to
close a top opening of the tank; a first transport unit configured to transport the plurality
of substrates into or out of the processing tank; and a dye solution supply unit
configured to supply a dye solution formed by solving the dye in a solvent into the
processing tank to such an extent that the plurality of substrates held in the boat are
sunk in the dye solution within the processing tank. During a dye solution processing,
the flow direction of the dye solution within the processing tank is switched by the dye
solution unit.
[0023]
A dye adsorption apparatus in a third viewpoint of the present invention is a dye
adsorption apparatus of adsorbing a dye into a porous semiconductor layer formed on a
treated surface of a substrate. The dye adsorption apparatus includes: a processing tank
configured to accommodate a plurality of substrates which are arranged in a row such
that the treated surfaces thereof are parallel to each other; a top cover configured to
close a top opening of the processing tank; a first transport unit configured to transport
the plurality of substrates into and out of the processing tank; a dye solution supply unit

configured to supply a dye solution formed by solving the dye in a solvent into the
processing tank to such an extent that the plurality of substrates held in the boat are
sunk in the dye solution within the processing tank; and a flow control unit configured
to switch a flow direction of the dye solution within the processing tank during a dye
adsorption processing.
[0024]
In the dye adsorption apparatus of the second or third viewpoint, a batch type
dye adsorption processing is performed for a plurality of substrates in the processing
tank. During the processing, the flow of the dye solution is formed in the processing
tank in a state where the top opening of the processing tank is closed, and the treated
surfaces of the substrates are exposed in the flow of the dye solution of high pressure.
Thus, aggregation or cohesion of the dye is hardly caused on a surface layer portion of
the porous semiconductor layer on the treated surface of each of the substrates, the dye
efficiently penetrates into the porous semiconductor layer, and thus the dye adsorption
into the porous semiconductor layer may proceed at high speed. Further, as the flow
direction of the dye solution within the processing tank is switched within the tank
during the processing, the penetration of the dye solution into the treated surface of each
of the substrates may be facilitated and the processing time may be significantly
shortened.
[0025]
Further, a dye sorption method according to the present invention is a dye
adsorption method of adsorbing a dye into a porous semiconductor layer formed on a
treated surface of a substrate. The dye adsorption method includes: a first step of
arranging a plurality of substrates in a row such that the treated surfaces thereof are
parallel to each other to be accommodated in the processing tank; a second step of

supplying a dye solution formed by solving the dye in a solvent into the processing tank
in a first direction parallel to the treated surfaces; and a third step of switching to a
second direction which is different from the first direction and parallel to the treated
surfaces and supplying the dye solution.
[0026]
In the dye adsorption method of the present invention, a batch type dye
adsorption processing is performed for a plurality of substrates within the processing
tank. As the flow direction of the dye solution within the processing tank is switched
within the tank during the processing, the penetration of the dye solution into the treated
surface of each of the substrates may be facilitated and the processing time may be
significantly shortened.
Effect of the Invention
[0027]
According to the dye adsorption apparatus or dye adsorption method according
to the present invention, the processing time of a step of adsorbing a dye into a porous
semiconductor layer may be significantly reduced by the configurations and actions as
described above.
Brief Description of the Drawings
[0028]
FIG 1 is a perspective view illustrating the entire configuration of a dye
adsorption processing system which includes a dye adsorption apparatus of an
exemplary embodiment of the present invention.
FIG. 2 is a perspective view illustrating a configuration of a transport

mechanism configured to transport substrates between processing units in the dye
adsorption processing system of FIG 1.
FIG 3 is a longitudinal sectional view illustrating a configuration of a dye
adsorption unit of an exemplary embodiment.
FIG 4 is a perspective view illustrating a configuration of a moving system in
the dye adsorption unit.
FIG 5 is a block diagram illustrating a dye solution supply unit and a flow
control unit in the dye adsorption unit.
FIG 6 is a plan view illustrating a state in which boards and substrates are
accommodated in the processing tank of the dye adsorption unit.
FIG 7 is a perspective view illustrating a state in which a pair of adjacent
substrates of which the rear surfaces face each other are supported by a body protrusion
at the rear surface sides thereof within the processing tank.
FIG 8 is a view illustrating a specific exemplary configuration of a dye solution
supply unit and a flow control unit in the dye adsorption unit.
FIG 9A is a plan view illustrating a step of a substrate carrying-in operation in
the dye adsorption unit.
FIG. 9B is a side view illustrating a step of the substrate carrying-in operation in
the dye adsorption unit.
FIG. 10 is a side view illustrating a step of the substrate carrying-in operation in
the dye adsorption unit.
FIG. 11A is a plan view illustrating a step of the substrate carrying-in operation
in the dye adsorption unit.
FIG. 1 IB is a side view illustrating a step of the substrate carrying-in operation
in the dye adsorption unit.

FIG 12A is a plan view illustrating a step of the substrate carrying-in operation
in the dye adsorption unit.
FIG 12B is a side view illustrating a step of the substrate carrying-in operation
in the dye adsorption unit.
FIG 13 A is a view illustrating the status of each unit when a dye solution
supply mode is selected in the dye adsorption unit.
FIG 13B is a view illustrating the status of each unit when a first flow mode is
selected in the dye adsorption unit.
FIG 13C is a view illustrating the status of each unit when a second flow mode
is selected in the dye adsorption unit.
FIG 13D is a view illustrating the status of each unit when a first flow mode is
selected in the dye adsorption unit.
FIG 13E is a view illustrating the status of each unit when a third flow mode is
selected in the dye adsorption unit.
FIG. 13F is a view illustrating the status of each unit when a fourth mode is
selected in the dye adsorption unit.
FIG 14 is a view illustrating a modified embodiment for varying the pressure
within the pressing tank in the dye adsorption unit.
FIG 15 is a view illustrating another modified embodiment for varying the
pressure within the pressing tank in the dye adsorption unit.
FIG 17 is a view illustrating an exemplary embodiment of the substrate support
unit of the dye adsorption unit.
FIG 18 is a view illustrating an exemplary embodiment of the substrate support
unit of the dye adsorption unit.
FIG 19 is a view illustrating an exemplary embodiment of the substrate support

unit of the dye adsorption unit.
FIG. 20 is a longitudinal sectional view illustrating a basic structure of a dye
sensitization solar cell.
Detailed Description to Execute the Invention
[0029]
Hereinbelow, exemplary embodiments of the present invention will be
described with reference to FIGS. 1 to 19.
[Configuration of Entire System]
[0030]
FIGS. 1 and 2 illustrate the entire configuration of the dye adsorption
processing system in which a dye adsorption apparatus of an exemplary embodiment of
the present invention is included.
[0031]
The dye adsorption processing system may be used, for example, in a step of
adsorbing a sensitizing dye into a porous semiconductor layer in a process of fabricating
a dye sensitization solar cell. In such a case, a transparent substrate 208, which is
formed with a transparent electrode 200 and a porous semiconductor layer 204 before
counterpart members (a counter electrode 202, a counter substrate 210, and an
electrolyte layer 206) are combined (FIG 20), will be a substrate to be treated G in the
dye adsorption device. In addition, in the substrate G, the surface formed with the
semiconductor layer 204 will be a surface to be treated ("treated surface") or a front
surface Gs.
[0032] Here, the transparent substrate 208 is made up of, for example, a transparent
inorganic material such as, for example, quartz or glass, or a transparent plastic material

such as, for example, polyester, acryl or polyimide. The transparent electrode 200 is
made up of, for example, fluorine doped SnC>2 (FTO) or indium-tin oxide (ITO). In
addition, the porous semiconductor layer 204 may be made up of, for example, a metal
oxide such as, for example, T1O2, ZnO or SnC>2. The substrate G has a predetermined
shape (e.g., a quadrilateral shape) and a predetermined size. A predetermined number of
substrates (e.g., 25 substrates) may be carried into/carried out of the dye adsorption
processing system by a transport vehicle or a transport robot (not illustrated) in a state
where the substrates are accommodated in cassettes C.
[0033]
As illustrated in FIG. 1, the dye adsorption processing system includes a
cassette carrying-in/carrying-out section 10 where carrying-in/carrying-out of the
cassettes C is performed, a loader/unloader section 12 where non-treated substrates G
are taken out from the cassettes C and treatment completed substrates G are
accommodated in the cassettes C, and a processing section 14 where a batch type dye
adsorption processing and a batch type post-processing (rinse and dry) for substrates G
are performed.
[0034]
Between the carrying-in/carrying-out section 10 and the loader/unloader section
12, a cassette C in which non-treated substrates G are accommodated is transferred from
the cassette carrying-in/carrying-out section 10 to the loader/unloader section 12, and a
cassette C in which the treatment completed substrates G are accommodated is
transferred from the loader/unloader section 12 to the cassette carrying-in/carrying-out
section 10 by a conveyance arm 16. In the loader/unloader section 12, the movement of
the substrates G between the transport device 18 in the processing section 14 and a
cassette C is performed by a predetermined number of substrates G (e.g., 50 substrates).

[0035]
In the processing section 14, the dye adsorption unit (dye adsorption apparatus)
20, the rinse unit 22 and the dry unit are 24 are arranged in a row in one horizontal
direction (in the X direction). As illustrated in FIG 2, the transport device 18 includes:
a chuck unit 26 configured to arrange the predetermined number of substrates G (e.g.,
50 substrates) horizontally in a row and to detachably grasp substrates G, and a transport
driving unit 28 configured to horizontally move along rails 27 extending in the unit
arranging direction (in the X direction) in the processing section 14 and to drive and
operate the chuck unit 26 on each of the units 20,22,24.
[0036]
The chuck unit 26 of the transport device 18 includes three parallel chuck arms
26a, 26b, 26c extending in the horizontal direction. Among them, the fixed low chuck
arm 26a at the center holds the bottom side edge of each of the substrate G by holding
recesses formed in a row on the top surface thereof. A pair of left and right movable
chuck arms 26b, 26c are configured to be movable to open/close while tracing a circular
arc in an outer circumference and to hold the left and right side edges of each of the
substrates G by holding grooves formed in a row on the inner surfaces thereof,
respectively.
[Configuration of Dye Adsorption Unit]
[0037]
FIGS. 3 and 4 illustrate a configuration of a moving system in the dye
adsorption unit 20 in the present exemplary embodiment. The dye adsorption unit 20
includes a processing tank 30 of which the top surface is opened as illustrated in FIG. 3
in order to perform a batch type dye adsorption processing for a predetermined number
of substrates G (in the present exemplary embodiment, 50 substrates), and includes, as a

moving system around the processing tank 30, a boat 32 configured to be capable of
going in and out of the processing tank 30 through the top opening, a boat transport unit
34 configured to transport the boat 32 into and out of the processing tank 30, and a top
cover 36 configured to detachably close the top opening of the processing tank 30.
[0038]
As illustrated in FIG 4, the boat 32 includes four parallel rod-shaped (or plate-
shaped) holding units 38a, 38b, 38c, 38d extending in the horizontal direction and
spaced apart from each other vertically and horizontally. The holding units 38a, 38b,
38c, 38d are formed, on the inner surface or top surface, with a plurality of holding
grooves (M) (e.g., 50 grooves) configured to arrange a predetermined number of
substrates G (e.g., 50 substrates) horizontally in a row and to detachably hold the
substrates G More specifically, the upper holding units 38a, 38b of left and right sides
hold the left and right side edges of the substrates by the holding grooves M formed in a
row on the inner surfaces thereof. In addition, the lower holding units 38c, 38d of the
left and right sides are configured to hold the lower side edges of the substrates G by the
holding grooves M formed in a row on the top surfaces thereof.
[0039]
In the present exemplary embodiment, in the predetermined number of
substrates G arranged horizontally in a row on the chuck unit 26 of the transport device
18 and further on the boat 32, the direction of the treated surface Gs of each of odd-
numbered substrates G and the direction of the treated surface Gs of even-numbered
surface are opposite to each other. Thus, the treated surfaces Gs, Gs of a pair of adjacent
(odd-numbered and even-numbered) substrates G, G are directed to the opposite
directions, i.e. the rear surfaces of the substrates G, G face each other.
[0040]

In the opposite side when viewed from the transport device 18, the ends of the
holding unit 38a, 38b, 38c, 38d of the boat 32 are integrally connected with each other
by a support plate 40, and a permanent magnet 42 is attached to the rear surface of the
support plate 40. Meanwhile, an electromagnet 46 is attached to the lower end of a lift
arm 44 of the boat transport unit 34 which extends vertically. When electric current is
applied to the electromagnet 46 by an excitation circuit (not illustrated) to excite the
electromagnet 46, the permanent magnet 42 is attracted to the electromagnet 46 by
electromagnetic force so that the boat 32 is integrally coupled to the lift arm 44. Also,
when the excitation of the electromagnet 46 is stopped, the lift arm 44 may be separated
from the boat 32.
[0041]
The lift arm 44 is coupled to a lift shaft 54 of a lift tower 52 through an arm
support unit or operating unit 48 of a rectangular parallelepiped shape and a horizontal
support member 50. The lift shaft 54 includes, for example, a ball-screw mechanism
and is configured to convert the rotational drive force of a motor 56 disposed on the
bottom of the lift tower 52 into vertical rectilinear drive force to move the lift arm 52 up
and down.
[0042]
The lift tower 52 is configured to be movable along lower and upper horizontal
guide rails 68, 70 extending in parallel to the longitudinal direction of the boat 32, i.e.,
in the arrangement direction of the substrates G in order to avoid the lift arm 44 from
being interfered with the top cover 36 above the processing tank 30. Thus, the lift arm
44 is adapted to be capable of moving between a first position (a working position)
where the lift arm 44 may be transported into or out of the processing tank 30 and a
second position (a retracted position) where the lift arm is retracted aside from the

processing tank 30 or a space above the tank 30.
[0043]
The top cover 36 has a shape and size corresponding to those of the top opening
of the processing tank 30 and is configured to be opened or closed by a top cover
operating unit 72 that is installed adjacent to the processing tank 30. The top cover
operating unit 72 includes, for example, an air cylinder or a linear actuator and raises
and lowers a manipulation rod 74 of a reversed-U shape which is connected to the top
cover 36, thereby moving the top cover 36 between a first position (close position)
where the top cover 36 is closely contacted with the top opening of the processing tank
30 and a second position (open position) where the top cover 36 is moved upward apart
from the top opening of the processing tank 30. Also, the top cover operating unit 72 is
configured to be capable of moving away from the boat transport unit 34 side, for
example, along a horizontal guide rail 76 extending in parallel to the longitudinal
direction of the boat 32 in order to avoid the top cover 36 from being interfered with the
lift arm 44 above the processing tank 30 when the boat 32 and the substrates G are
transported into or out of the processing tank 30.
[0044]
FIG. 5 illustrates the configuration of the dye solution supply unit and the flow
control unit in the dye adsorption unit 20 in the present exemplary embodiment. In the
present exemplary embodiment, first and second dye solution supply units 80, 82 are
provided so as to supply dye solution into the processing tank 30 and first and second
flow control units 84, 86 are provided so as to control the flow of the dye solution in the
processing tank 30.
[0045]
On the left and right inner walls of the processing tank 30 (a pair of inner walls

opposed to each other in the X direction) are provided with left upper and lower ports
88L, 90L and right upper and lower ports 88R, 90R, respectively. Here, the left upper
port 88L and the right upper port 88R are installed at a height in the vicinity of the
processing tank 30 and extend or are discretely distributed in the longitudinal direction
of the processing tank 30 (in the Y direction). In addition, the left lower port 90L and
right lower port R are installed at a position at a height in the vicinity of the bottom of
the processing tank 30 and extend or are discretely distributed in the longitudinal
direction of the processing tank 30 (in the Y direction).
[0046]
The first dye solution supply unit 80 and the first flow control unit 84 are
connected to the left upper port 88L and the right lower port 90R of the processing tank
30. Meanwhile, the second dye solution supply unit 82 and the second flow control unit
86 are connected to the right upper port 88R and the left lower port 90L of the
processing tank 30. The specific configurations and actions of the dye solution supply
unit 80, 82 and the flow control unit 84, 86 will be described in detail below.
[0047]
The dye solution used in the dye adsorption unit 20 is formed by solving a
sensitizing dye in a solvent with a predetermined concentration. As for the sensitizing
dye, for example, a metal complex such as, for example, metal phthalocyanine, or an
organic dye such as, for example, a cyanine-based dye or a basic dye may be used. As
for the solvent, for example, alcohols, ethers, amides, or a hydrocarbon may be used.
[0048]
One or more drain ports 92 are formed in the bottom of the processing tank 30.
The drain ports 92 are communicated with a drain tank (not illustrated) through a drain
pipe 94. An open/close valve 96 is provided on the way of the drain pipe 94.

[0049]
As illustrated in FIGS. 5 and 6, the predetermined number of substrates G
which are subject to a batch type dye adsorption processing in the processing tank 30
are held at left and right side edges and bottom side edges by the holding unit 38a, 38b,
38c, 38d of the boat 32 and supported at the rear surfaces and top side edges by the
support members 98, 100 provided in the processing tank 30 and on the top cover 36 in
a state where the substrates G are arranged in a row with the treated surfaces Gs facing
horizontally.
[0050]
More specifically, a support member 98 of the processing tank 30 includes a
horizontal support plate 102 fixed to the bottom of the processing tank 30, and a
predetermined number of rod-shaped or plate-shaped body protrusions 104 (e.g., 25
protrusions) extending vertically from the horizontal support plate 102 preferably to a
position adjacent to the top opening of the processing tank 30. Here, the body
protrusions 104 are arranged in a row in the direction (in the Y direction), which is the
same as the arrangement direction of the predetermined number of substrates G (e.g., 50
substrates) which are arranged on the boat 32 horizontally in a row, at a predetermined
spacing which corresponds to that of the substrates G
[0051]
As described above, the predetermined number of substrates G are arranged in a
row on the boat 32 in a state where the treated surfaces Gs, Gs of a pair of adjacent
substrates G, G are directed to the opposite directions, i.e. the rear surfaces thereof face
each other. As illustrated in FIGS. 6 and 7, each of the body protrusions 104 are
positioned between the adjacent substrates G, G in the pair such that the rear surfaces
thereof face each other, and contacted with each of the rear surfaces of the substrates G,

G at the central portion thereof in the widthwise direction of the substrates (in the X
direction).
[0052]
In addition, the support member 100 of the top cover 36 includes a
predetermined number of rod-shaped or plate-shaped cover protrusions 106 (e.g., 25
pairs at left and right sides) which extend vertically downward from the bottom surface
of the top cover 36. Here, the cover protrusions 106 are arranged in two rows at a
predetermined spacing which corresponds to that of the predetermined number of
substrates G (50 substrates) arranged horizontally in a row on the boat 32.
[0053]
In addition, a seal member, for example, an O-ring 108 is attached to the
peripheral edge of the bottom surface of the top cover 36 to seal the interior of the
processing tank 30 when the top opening of the processing tank 30 is closed by the top
cover 36.
[0054]
As illustrated in FIG 6, in each pair of substrates G, G, of which the rear
surfaces are adjacent to face each other within the processing tank 30, the treated
surface Gs of one substrate G of the pair and the treated surface Gs of the neighboring
substrate G in the opposite side face each other, and the treated surface Gs of the other
substrate G of the pair and the treated surface Gs of the neighboring substrate G in the
opposite side also face each other. Like this, between a pair of neighboring substrates G,
G, of which the treated surfaces Gs, Gs face each other, neither the body protrusions 104
nor the cover protrusions 106 exist, thereby forming a flow passing space RS in which
the dye solution may flow freely and smoothly in the widthwise direction of the
substrates (in the X direction).

[0055]
On the contrary, between the adjacent substrates G, G of each pair of which the
rear surfaces face each other, the body protrusions 104 and the cover protrusions 106
function as baffles, thereby forming a stay space TS where the dye solution is hard to
flow in the widthwise direction of the substrates (in the X direction).
[0056]
In this manner, within the processing tank 30, a flow passing space RS and stay
space TS are alternately formed with a substrate G being between them along the
arrangement direction of the substrates G (along the Y direction). Thus, the treated
surface Gs of each of the substrates G on the boat 32 faces a flow passing space RS and
the rear surface thereof faces the stay space TS.
[0057]
In the present exemplary embodiment, the discharge openings (or suction
openings) of the left ports 88L, 90L and the right ports 88R, 90R are arranged at
opposite positions through the flow passing spaces RS, respectively, in the widthwise
direction of the substrates (in the X direction). Thus, as described later, for example,
when the flow of the dye solution is controlled within the processing tank 30 using the
right upper ports 88R and the left lower ports 90L by operating the second flow control
unit 86, a large amount of dye solution introduced into the processing tank 30 from the
right upper ports 88R flows within each of the flow passing spaces RS along the treated
surface Gs of each of the substrates G and arrives at the left lower ports which are the
outlets (suction openings).
[0058]
In the present exemplary embodiment, as illustrated in FIG. 6, in the substrate
arrangement direction (in the Y direction), the spacing size of the flow passing spaces

RS is set to be relatively large and the spacing size of the stay spaces TS is set to be
relatively small. Thus, the penetration efficiency of the dye solution, which flows
within the processing tank 30, into the porous semiconductor layer 204 (FIG. 19)
formed on the treated surface Gs of each of the substrates G may be further enhanced.
[0059]
FIG 8 illustrates a specific configuration example of the dye solution supply
units 80, 82 and the flow control units 84, 86 of the present exemplary embodiment.
[0060]
The first dye solution supply unit 80 and the first flow control unit 84 share
some or all of a first tank 110, a first pump 112, a first control valve 114, a plurality of
open/close valves 116, 118, 120, 122, 124, 126 and a plurality of pipes 128, 130, 132,
134, 136. Here, the first tank 110 stores the dye solution for use in a dye adsorption
processing. The inlet side of the first pump 112 is connected to the first tank 110
through the pipe 128. An open/close valve 116 is provided on the way of the pipe 128.
The outlet side of the first pump 112 is connected to a left upper port 88L of the
processing tank 30 through the first control valve 114 and the pipe 130, and connected
to the right lower port 90R of the processing tank 30 through the first control valve 114
and the pipe 132.
[0061]
On the way of the pipe 130, the open/close valve 118 is provided, and on the
way of the pipe 132, the open/close valves 120, 122 are provided. The pipe 134
connects a node Ni provided on the pipe 128 between the open/close valve 116 and the
inlet side of the pump 112 and the node N2 provided on the pipe 130 between the
open/close valve-118 and the left upper port 88L. On the way of the pipe 134, the
open/close valve 124 is provided. In addition, the pipe 136 connects the node Ni and a

node N3 provided on the pipe 132 between the open/close valves 120, 122. On the way
of the pipe 136, the open/close valve 126 is provided. A thermostat 138 is attached to
the first tank 110 so as to control the temperature of the dye solution to a temperature
suitable for the dye adsorption processing, for example, to 40 D to 60 D.
[0062]
Meanwhile, the second dye solution supply unit 82 and the first flow control
unit 86 shares some or all of a second tank 140, a second pump 142, a second control
valve 144, a plurality of open/close valves 146, 148, 150, 152, 154, 156 and a plurality
of pipes 158, 160, 162, 164, 166. Here, the second tank 140 stores the dye solution for
use in the dye adsorption processing. The inlet side of the second pump 142 is
connected to the second tank 140 through the pipe 158. On the way of the pipe 158, the
open/close valve 146 is provided. The outlet side of the second pump 142 is connected
to the right upper port 88R of the processing tank 30 through the second control valve
144 and the pipe 160, and connected to the left lower port 90L of the processing tank 30
through the second valve 144 and the pipe 162.
[0063]
On the way of the pipe 160, the open/close valve 148 is provided, and on the
way of the pipe 162, the open/close valves 150, 152 are provided. The pipe 164
connects a node N4 provided on the pipe 158 between the open/close valve 146 and the
inlet side of the pump 142 and a node N5 provided on the pipe 160 between the
open/close valve 148 and the right upper port 88R. On the way of the pipe 164, the
open/close valve 154 is provided. In addition, the pipe 166 connects the node N4 and a
node N6 provided on the pipe 162 between the open/close valves 150, 152. On the way
of the pipe 166, the open/close valve 156 is provided. A thermostat 168 is attached to
the second tank 140 so as to control the temperature of the dye solution to a temperature

suitable for the dye adsorption processing, for example, to 40 D to 60 D.
[0064]
Respective units (pumps, control valves, open/close valves) in the dye solution
supply units 80, 82 and the flow control units 84, 86 are operated under the control of
the controller 170. The controller 170 includes a microcomputer and an interface and
controls the operation of each of the units in the dye adsorption unit 20, including the
above-described moving system (FIGS. 3 and 4) and the operating sequence of the
entire apparatus.
[0065]
The processing tank 30 is provided with a pressure gage 172. The pressure
gage 172 measures pressure at a predetermined position within the processing tank 30
(e.g., at a position adjacent to the top opening). The controller 170 monitors or
feedbacks the measured pressure value Kp from the pressure gage 172 to control the
operation of the flow control units 84, 86.
[Action of Dye Adsorption Unit/Substrate Carrying-in Operation]
[0066]
Next, descriptions will be made as to the operations of carrying non-processed
substrates G to be subject to the batch type dye adsorption processing into the
processing tank 30 in the dye adsorption unit 20 with reference to FIGS. 9 to 12.
[0067]
The transport device 18 (FIGS. 1 and 2) is moved from the loader/unloader
section 12 to the dye adsorption unit 20 along the rail 27 by the transport driving unit 28
in a state where the predetermined number (e.g., 50) non-processed substrates G are
arranged horizontally in a row and grasped by the chuck unit 26 (FIG. 9A).

[0068]
At this time, the boat 32 is positioned inside the processing tank 30 of the dye
adsorption unit 20 in an empty state without being loaded with substrates G The boat
transport unit 34 separates and retracts the lift arm 44 from the boat 32. Before the
transport device 18 comes, the top cover operating unit 72 lifts up and retracts the top
cover 36 above the processing tank 30 and to a position where the top cover 36 does not
interfere with the lift arm 44 (FIG. 9A). As such, the transport device 18 locates the
chuck unit 26 in which the non-processed substrates G are grasped, just above the
processing tank 30.
[0069]
Just after this, the boat transport unit 34 moves the lift arm 44 from the
retracted position to the working position and lowers the lift arm 44 into the boat 32,
and excites the electromagnet 46 so that the lift arm 44 is coupled to the boat 32.
Subsequently, the boat transport unit 34 lifts up the lift arm 44 together with the boat 32
in the empty state (FIG. 10).
[0070]
By the upward movement of the boat 32, each of the holding grooves M formed
in the holding units 38a, 38b, 38c, 38d of the boat 32 is engaged with the left, light or
bottom side edge of corresponding one of the substrates G In cooperation with the
upward movement of the boat 32, the transport device 18 retracts the left and right
moving chuck arms 26b, 26c to the outside. As such, the predetermined number of non-
processed substrates G (e.g., 50 substrates) are transferred from the chuck unit 26 of the
transport device 18 to the boat 32 just above the processing tank 30 while maintaining
the state arranged horizontally in a row (FIGS. 11A and 11B).
[0071]

Thereafter, the transport device 18 moves the chuck unit 26 horizontally (in the
X direction) at a position at a height between the boat 32 and the processing tank 30,
and starts for other units 22, 24 or the loader/unloader section 12 from the dye
adsorption unit 20.
[0072]
After the transport device 18 is moved, the boat transport unit 34 lowers the lift
arm 42 and the boat 32 in unison so that the lift arm 42, the boat 32 and the
predetermined number of substrates G (e.g., 50 substrates) are carried into or
accommodated in the processing tank 30 (FIGS. 12A and 12B). At this time, although
the processing tank 30 may contain the dye solution, it may not matter if the tank 30 is
empty without containing the dye solution at all.
[0073]
Thus, when the predetermined number of non-processed substrates G are
carried into the processing tank 30 in a state where they are arranged horizontally in a
row on the boat 32, the boat transport unit 34 releases the excitation of the
electromagnet 46, then separates the lift arm 42 from the boat 32 and retracts the lift
arm 42 to the outside of the processing tank 30. Just after this, the top cover operating
unit 72 lowers the top cover 36 so that the top opening of the processing tank 30 is
closed by the top cover 36. In addition, during the dye adsorption processing, high
pressure is applied to the top cover 36 from the inside of the processing tank 30 and
thus, it is required to press the top cover 36 downward against the internal pressure.
The top cover operating unit 72 may function to press the top cover 36 downward
during the processing to maintain the fluid-tightness of the inside of the processing tank
30.
[Action of Dye Adsorption Unit /Operation of Controlling Supply and Flow of

Dye Solution]
[0074]
Next, descriptions will be made as to the operations of controlling the supply
and flow of the dye solution in the dye adsorption unit 20 with reference to FIGS. 13 A
to 13H.
[0075]
Firstly, in a case where the dye solution is not contained in the processing tank
30 or insufficiently contained in the processing tank 30 at the time when the boat 32, on
which the predetermined number of non-processed substrates G are arranged and
maintained horizontally in a row, is carried into the processing tank 30, the dye solution
supply mode is selected first.
[0076]
Typically, in the dye solution supply mode, the first and second dye solution
supply units 80, 82 are operated concurrently. More specifically, as illustrated in FIG.
13A, in the first dye solution supply unit 80, the first pump 112 is turned ON, the
open/close valves 116, 118, 120, 122 are turned to the open (ON) state, and the other
open/close valves 124, 126 are turned to close (OFF) state. Thus, the dye solution
drawn up from the first tank 110 by the first pump 112 passes through the pipes 130,
132 and is supplied to the inside of the processing tank 30 from the left upper port 88L
and the right lower port 90R.
[0077]
In addition, in the second dye solution supply unit 82, the second pump 142 is
turned ON, the open/close valves 146, 148, 150, 152 are turned to the open (ON) state,
and the other open/close valves 154, 156 are turned to the close (OFF) state. Thus, the
dye solution drawn up from the second tank 140 by the second pump 142 passes

through the pipes 160, 162, and is supplied to the inside of the processing tank 30 from
the right upper port 88R and left lower port 90L.
[0078]
However, when the shortage of the dye solution in the processing tank 30 is not
so much, only one side of the first and second dye solution supply units 80, 82, for
example, only the first dye solution supply unit 80 may be operated. In such a case,
although both of the left upper port 88L and the right lower port 90R may be used, it
may not matter if only one side thereof is used. For example, when only the left upper
port 88L is used as the supply port, only the open/close valve 116 of the pipe 128 and
the open/close valve 118 of the pipe 132 may be turned to the open (ON) state and all of
the other open/close valves may be maintained in the close (OFF) state.
[0079]
In addition, in the dye solution supply mode, old dye solution may be
substituted with new dye solution in the processing tank by opening the open/close
valve 96 of the drain pipe 94.
[0080]
Also, when the dye solution supply mode is operated, it is desirable to fill the
inside of the processing tank 30 with dye solution by the dye solution supply mode. For
this purpose, the non-processed substrates G may be carried into the processing tank 30,
then the processing tank 30 may be fully filled with dye solution by the dye solution
supply units 80, 82 while delaying the operation of the top cover operating unit 72, and
then the top cover 36 may lowered to close the top opening of the processing tank 30.
[0081]
When the filling or replenishing of the dye solution to the processing tank 30 by
the dye solution supply units 80, 82 is completed through the above-described

processes, the dye adsorption processing is started. Typically, the operation of the flow
control units 83, 86 is started simultaneously with the starting of the dye adsorption
processing.
[0082]
In the operation of the flow control units 84, 86, various modes may be selected
in connection with the flow of the processing solution within the processing tank 30.
For example, as illustrated in FIGS. 13B and 13C, modes of stopping the second flow
control unit 86 and operating only the first flow control unit 84 (first and second flow
modes) may be selected.
[0083]
In the first flow mode of FIG 13B, the first flow control unit 84 turns On the
first pump 112, turns the open/close valves 118, 122, 126 to the open (ON) state, and
turns the other open/close valves 116, 120, 124 to the close (OFF) state. Accordingly,
the dye solution discharged from the outlet side of the first pump 112 passes through the
first control valve 114 and the pipe 130 and is introduced into the processing tank 30
from the left upper port 88L. In addition, the dye solution discharged to the outside of
the processing tank 30 from the right lower port 90R returns to the inlet side of the first
pump 112 through the pipes 132, 136, 128. Meanwhile, the second flow control unit 86
maintains all of the second pump 142 and the open/close valves 146, 148, 150, 152,
154,156 in the OFF state.
[0084]
When the first flow mode is selected in this manner, a flow of the dye solution
is formed in the processing tank 30 from the left upper port 88L to the right lower port
90R. That is, the dye solution discharged from each discharge opening of the left upper
port 88L arrives at each suction opening of the right lower port 90R in the opposite side

through each of the flow passing spaces RS spreading in front of the dye solution. At
the right upper port 88R and the left lower port 90L, the dye solution does not go in and
out.
[0085]
Since the top opening of the processing tank 30 is closed by the top cover 36,
the pressure within the processing tank 30 is considerably high as compared to the
pressure when the top opening is opened to the atmosphere, and in each of the flow
passing spaces RS, the flow of dye solution is formed under this high pressure. Here,
all the substrates G on the boat 32 accommodated in the processing tank 30 are arranged
such that the treated surfaces Gs face the flow passing spaces RS, thereby being exposed
to the flow of the dye solution of high pressure. Thus, the dye solution may penetrate
into the treated surface Gs of each of the substrates G rapidly and smoothly, aggregation
or cohesion of dye is hardly caused on a surface layer portion of the porous
semiconductor layer 204 of the treated surface Gs, and thus, the dye may be efficiently
and rapidly adsorbed into the porous semiconductor layer 204.
[0086]
In the second flow mode of FIG 13C, the first flow control unit 84 turns ON
the first pump 112, turns the open/close valves 120, 122, 124 to the open (ON) state,
and turns the other open/close valves 116, 118, 126 to the close (OFF) state.
Accordingly, the dye solution discharged from the outlet side of the first pump 112
passes through the first control valve 114 and the pipe 132 and is introduced into the
processing tank 30 from the right lower port 90R. In addition, the dye solution
discharged to the outside of the processing tank 30 from the right upper port 88L passes
through the pipes 130, 134, 128 and returns to the inlet side of the first pump 112.
Meanwhile, the second flow control unit 86 maintains all of the second pump 142 and

the open/close valves 146,148,150,152,154,156 in the OFF state.
[0087]
Like this, according to the second flow mode, in the processing tank 30, the
flow of the dye solution is formed from the right lower port 90R to the left upper port
88L. That is, the dye solution discharged from each discharge opening of the right
lower port arrives at each suction opening of the left upper port 88L in the opposite side
through each of the flow passing space RS spreading in front of the dye solution. Also,
at the right upper port 88R and left lower port 90L, the dye solution does not go in and
out.
[0088]
Also in this case, all the substrates G on the boat 32 accommodated in the
processing tank 30 are arranged such that each of the treated surfaces Gs face the flow
passing spaces RS, thereby being exposed to the flow of the dye solution of high
pressure. Accordingly, the dye solution may penetrate into the treated surface Gs of
each of the substrates G rapidly and smoothly, aggregation or cohesion of the dye is
hardly caused on the surface layer portion of the porous semiconductor layer 204 of the
treated surface Gs, and thus, the dye may be adsorbed into the porous semiconductor
layer 204 efficiently and rapidly.
[0089]
Also, in the present exemplary embodiment, as illustrated in FIG 13D or FIG.
13E, the modes of stopping the first flow control unit 84 and operating only the second
flow control unit 86 (third and fourth flow modes) may be selected.
[0090]
In the third flow mode of FIG 13D, the second flow control unit 8 turns ON the
second pump 142, turns open/close valves 148, 152, 156 to the open (ON) state, and

turns other open/close valves 146, 150, 154 to the close (OFF) state. Thus, the dye
solution discharged from the outlet side of the second pump 142 passes through the
second control valve 144 and the pipe 160 and is introduced into the processing tank 30
from the right upper port 88R. And, the dye solution discharged to the outside of the
processing tank 30 from the left lower port 90L returns to the inlet side of the second
pump 142 through the pipes 162, 166, 158. Meanwhile, the first flow control unit 84
maintains all of the first pump 112 and the open/close valves 116, 118, 120, 122, 124,
126 in the OFF state.
[0091]
When the third flow mode is selected in this manner, a flow of the dye solution
is formed from the right upper port 88R to the left lower port 90L in the processing tank
30. That is, the dye solution discharged from each discharge opening of the right upper
port 88R arrives at each suction opening of the left lower port 90L in the opposite side
through each of the flow passing spaces RS spreading in front of the dye solution. At
the left upper port 88L and the right lower port 90R, the dye solution does not go in and
out.
[0092]
Also in this case, all the substrates G on the boat 32 accommodated in the
processing tank 30 are arranged such that the treated surface Gs face the flow passing
spaces RS, thereby being exposed to the flow of the dye solution of high pressure.
Thus, the dye solution penetrates into the treated surface Gs of each substrate rapidly
and smoothly and thus, the dye may be adsorbed from the surface layer into the inside
of the porous semiconductor layer 204 of the treated surface efficiently and rapidly.
[0093]
In the fourth flow mode of FIG. 13E, the second flow control unit 86 turns ON

the second pump 142, turns the open/close valves 150, 152, 154 to the open (ON) state,
and turns the other open/close valves 146, 148, 156 to the close (OFF) state. Thus, the
dye solution discharged to the outlet side of the second pump 142 passes through the
second control valve 144 and the pipe 162 and is introduced into the processing tank 30
from the left lower port 90L. In addition, the dye solution discharged to the outside of
the processing tank 30 from the right upper port 88R passes through the pipes 160,164,
158 and returns to the inlet side of the second pump 142. Meanwhile, the first flow
control unit 84 maintains all of the first pump 112 and the open/close valves 116, 118,
120,124, 126 in the OFF state.
[0094]
Like this, according to the fourth flow mode, a flow of the dye solution is
formed from the left lower port 90L to the right upper port 88R in the processing tank
30. That is, the dye solution discharged from each discharge opening of the left lower
port 90L arrives at each suction opening of the right upper port 88R through each of the
flow passing spaces RS spreading in front of the dye solution. Also, at the left upper
port 88L and the right lower port 90R, the dye solution does not go in and out.
[0095]
Also in this case, all the substrates G on the boat 32 accommodated in the
processing tank 30 are arranged such that the treated surface Gs face the flow passing
spaces RS, thereby being exposed to the flow of the dye solution of high pressure.
Thus, the dye solution penetrates into the treated surface Gs of each substrate rapidly
and smoothly, and thus, the dye may be adsorbed from the surface layer into the inside
of the porous semiconductor layer 204 of the treated surface efficiently and rapidly.
[0096]
In the first to fourth flow modes, the dye solution is circulated between the

inside and outside of the processing tank 30. Thus, as the dye adsorption processing
proceeds, the dye in the dye solution gradually decreases and thus, the concentration of
the dye solution gradually decreases. Accordingly, in order to maintain or recover the
concentration of the dye solution in a set range, it is desirable to properly change the
modes during the dye adsorption processing to a mode (fifth flow mode) in which, for
example, as illustrated in FIG 13F, the open/close valve 96 of the drain pipe 94 is
turned to the open (ON) state to control the flow of the dye solution while substituting
the old dye solution with new dye solution.
[0097]
In the fifth flow mode, the first and second flow control units 84, 86 turn the
first and second pumps 112, 142, respectively, and turn the open/close valves 116, 118,
and the open/close valves 146, 148 to the open (ON) state, respectively, and turn the
other open/close valves 120, 122, 124, 126 and the open/close valves 50, 152, 154, 156
to the close (OFF) state, respectively. Thus, the dye solution (new solution) discharged
from the outlet sides of the first and second pumps 112, 142 passes through the first and
second control valves 114, 144 and the pipes 130, 160 and is introduced into the
processing tank 30 from the left and right upper ports 88L, 88R. Meanwhile, the dye
solution (old solution) discharged to the outside of the processing tank 30 from the drain
port 92 is sent to the drain tank through the drain pipe 94 or recovered. As such, the
substitution of old dye solution with new dye solution is conducted from the upper side
toward the lower side (bottom) in the processing tank 30.
[0098]
At this time, within processing tank 30, the dye solution coming out from each
discharge opening of the left and right upper ports 88L, 88R arrives at a drain port in the
bottom side through each of the flow passing spaces RS spreading in front of it. Also in

such a case, all the substrates G on the boat 32 accommodated in the processing tank 30
lie such that the treated surfaces Gs thereof face the flow passing spaces RS,
respectively, thereby being exposed to the flow of the dye solution of high pressure.
Thus, the dye solution penetrates into the treated surface Gs of each substrate G rapidly
and smoothly, and thus, the dye may be adsorbed from the surface layer into the inside
of the porous semiconductor layer 204 of the treated surface efficiently and rapidly. In
addition, as an aspect of the fifth flow mode, only one side of the first and second flow
control units 84, 86 may be operated to stop the other side.
[0099]
In the present exemplary embodiment, a sequence of a dye adsorption
processing may be programmed by selectively combining various types of flow modes
as described above. As described above, during the processing, the flow direction of the
dye solution within the processing tank 30 may be variously changed and thus, the
penetration of the dye solution in relation to the treated surface Gs of each of the
substrates G may be further facilitated and the dye adsorption efficiency or rate may be
further enhanced.
[0100]
Also, in the present exemplary embodiment, the pressure or flow late of the dye
solution within the processing tank 30 may be arbitrarily varied using the pressure
control function or flow rate control function of the control valves 114, 144 provided in
the first and second flow control units 84, 86. As described above, since the dye
adsorption processing of this type causes the dye solution to penetrate into the porous
semiconductor layer of the treated surface of a substrate so that the dye is adsorbed from
the surface layer of the semiconductor layer into the porous semiconductor layer, the
dye adsorption efficiency or rate tends to decrease as the processing time passes. Thus,

a method of linearly increasing the pressure or flow rate within the processing tank 30
as the processing time passes or a method of increasing the pressure or flow rate within
the processing tank 30 step by step, during the processing time (more preferably, in the
latter half of the processing time or just before the end of the processing time) may be
properly employed.
[0101]
As described above, in the dye adsorption unit 20 of the present exemplary
embodiment, since the flow of the dye solution is formed within the processing tank 30
under high pressure, and the treated surfaces Gs of the substrates G are exposed in the
flow of the dye solution, aggregation or cohesion of dye is hardly caused on a surface
layer portion of the porous semiconductor layer 204 of the treated surface Gs of each of
the substrates, the dye efficiently penetrates into the porous semiconductor layer 204,
and thus, the dye adsorption into the porous semiconductor layer 204 may proceed at
high speed. By using the method of the present exemplary embodiment, the time
required for a dye adsorption processing in a dye sensitization solar cell fabrication
process may be significantly reduced. For example, one batch processing may be
completed within 10 minutes.
[0102]
In addition, in the dye adsorption unit 20 of the present exemplary embodiment,
a plurality of substrates G that are subject to the batch type dye adsorption processing
within the processing tank 30 are supported at the rear sides and top side edges thereof
by the support members 98, 100 which are provided in the processing tank 30 and on
the top cover 36, respectively, the substrates are rarely flexed or inclined in the flow of
the dye solution, especially in relation to the pressure received from a flow passing
space RS. Thus, the damage or deformation of the substrates G may be suppressed. In

addition, when the protrusions 104, 106 of the support members 98, 100 come into
contact with the rear surfaces of the substrates G, the contact may be any of plane
contact, line contact and point contact. The treated surface Gs of the substrates may not
affected by any of the contact types.
[0103]
The protrusions 104, 106 of the support members 98, 100 may maintain the
posture of the substrates G stably within the processing tank 30 in this manner. In
addition, the protrusions 104, 106 may suppress the flow of the dye solution along the
rear surfaces of the substrates as described above and as the reflective effects thereof,
the protrusions 104,106 of the support members 98,100 may serve to facilitate the flow
of the dye solution along the front surfaces (treated surfaces Gs) of the substrates G and
moreover, enhance the dye adsorption efficiency.
[0104]
In addition, when the batch type dye adsorption processing is ended as the
predetermined processing time has lapsed, the operation of carrying treatment
completed substrates G out of the processing tank 30 in a state where all the dye
solution supply units 80, 82 and the flow control units 84, 86 stop the operations
thereof. Although not illustrated, the carrying-out operation of treatment completed
substrates are performed in the order reverse to that of the above-described carrying-in
operation of non-processed substrates, i.e. in the order like turning time back.
[0105]
That is, first, the top cover operating unit 72 is operated to lift up the top cover
36, thereby opening the top opening of the processing tank 30 to the atmosphere. Then,
the boat transport unit 34 moves the lift arm 44 from the retracted position to the
working position and lowers the lift arm 44 into the boat 32, and excites the

electromagnet 46 to couple the lift arm 44 to the boat 32. In addition, the boat transport
unit 34 lifts up the boat 32 loaded with the treatment completed substrates G and the
boat 32 together with the lift arm 44. Just after this, the transport device 18 (FIGS. 1
and 2) moves to the dye adsorption unit 2.6 in a state where the chuck unit 26 is empty
without grasping substrates and the left and right movable chuck arms 26b, 26c are
spread to the outside, and locates the chuck unit 26 just above the processing tank 30.
In addition, simultaneously when the boat transport unit 34 lowers the boat 32, transport
device 18 moves the left and right chuck arms 26b, 26c inwardly to approach each other
at predetermined timing so that the left and right side edges of the substrates G are held
in the holding recesses of the opposite movable chuck arms 26b, 26c, respectively. By
the downward movement of the boat 32 and the chucking operation of the chuck unit
26, the predetermined number of treatment completed substrates G are transferred from
the boat 32 to the chuck unit 26 of the transport device 18 in the state where they are
arranged horizontally in a row.
[0106]
Upon receiving the predetermined number of treatment completed substrates G
as described above, the transport device 18 moves from the dye adsorption unit 20 to
the neighboring rinse unit 22 where the treatment completed substrates G are subject to
a rinse processing. The rinse unit 22 has a well-known configuration and projects a
rinse solution violently evenly over the treatment completed substrates G by, for
example, a rinse nozzle so that the dye solution adhered to the front and rear surfaces of
each of the substrates G is substituted with the rinse solution.
[0107]
The predetermined number of treatment completed substrates G, to which the
rinse processing has been completed in the rinse unit 22, are carried into the

neighboring dry unit 24 by the transport device 18. The dry unit 24 also has a known
configuration and blows dry air or nitrogen gas violently to each of the substrates G by,
for example, an air nozzle so that the rinse solution adhered to the front and rear
surfaces of each of the substrates G is removed.
[0108]
The predetermined number of treatment completed substrates G, to which the
dry processing has been completed in the dry unit 22, is transported to the neighboring
loader/unloader unit 12 by the transport device 18. In the present exemplary
embodiment, in the loader/unloader unit 12, the predetermined number of treatment
completed substrates (e.g., 50 substrates) G are divided into two sets (25 substrates per
each set) and transferred from the chuck unit 26 of the transport device 18 to two
cassettes C. In that event, the substrates may be accommodated in the cassettes C by
arranging all the neighboring substrates G, G, of which the rear sides have faced each
other, to face the same direction. The treatment completed substrates G transferred to
the cassettes C are transferred to the cassette carrying-in/carrying-out section 10 by the
conveyance arm 16 and taken out from the dye adsorption processing system (FIG. 1)
by a transport vehicle or a transport robot.
[Other Exemplary Embodiment or Modified Embodiment]
[0109]
In the above-described exemplary embodiments, the pressure within the
processing tank 30 may be varied or adjusted using the pressure control function of the
control valves 114, 144 provided in the first and second flow control units 84, 86.
However, in order to obtain a larger amplitude or variation range for the pressure within
processing tank 30, for example, a configuration may be properly employed in which a
bellows 170 is attached to the bottom of the processing tank 30 to be expanded and

contracted by a rectilinear driving unit 172 such as, for example, a cylinder, as
illustrated in FIG 14. In such a case, when the driving shaft is moved forward or
upward to contract the bellows 170 as illustrated in FIG 14A, the volume of the
processing tank 30 decreases and the pressure increases. On the contrary to this, when
the driving shat 174 is moved rearward or downward as illustrated in FIG 14B, the
volume of the processing tank 30 increases and the pressure decreases.
[0110]
As a separate exemplary embodiment, as illustrated in FIG 15, a NOWPACK
(brand name) type configuration may also be employed in which a processing tank 30'
made up of a flexible material is accommodated in an external tank 178 made up of a
rigid material with a sealable gap 180 being provided between them. In such a case, the
pressure within the processing tank 30' may be varied or adjusted by making the fluid
within the gap 180 go in and out of the gap 180 to contract or expand the pressing tank
30'.
[0111]
In the above-described exemplary embodiments, both the processing tank 30
and the top cover 36 are provided with the support members 98 and 100 that support the
substrates G at the rear sides thereof. However, only one of the processing tank 30 and
the top cover 36 may be provided with the support member 98 (100).
[0112]
In addition, for example, as illustrated in FIG. 16A, it is also possible to provide
a plurality of body protrusions 104, for example, three body protrusions 104 may be
provided on the support member 98 which is provided in the processing tank 30.
Alternatively, for example, as illustrated in FIGS. 16B and 16C, the cover protrusions
106 of the support body 100 provided on the top cover 36 may extend to a position in

the vicinity of lower ends of the substrates G.
[0113]
In the above-described exemplary embodiments, the predetermined number of
substrates G held on the boat 32 within the processing tank 30 are arranged in such a
manner that a pair of adjacent substrates G, G are arranged so that the treated surfaces
Gs, Gs thereof are directed in the opposite directions, i.e., the rear surfaces of thereof
face each other. In addition, the body protrusion 104 and the cover protrusion 106 are
disposed (inserted) in the space TS of the substrates G, G of the pair. However, on the
boat 32, all or some of the substrates may be arranged horizontally in a row such that
the treated surfaces are directed to the same direction. Also in such a case, the
configuration in which the body protrusion 104 of the substrate support unit 98 is
disposed (inserted) at the rear side of each of the substrates G as illustrated in FIGS.
17A and 17B and/or the configuration in which the cover protrusion 106 of the substrate
support unit 100 is disposed (inserted) at the rear side of each of the substrates G as
illustrated in FIGS. 17C and 17D may be employed.
[0114]
However, in the configuration where all or some of the substrates G are
arranged horizontally in a row on the boat 32 such that the treated surfaces thereof are
directed to the same direction, when the body protrusion 104 of the substrate support
unit 98 and/or the cover protrusion 106 of the substrate support unit 100 are provided,
the entire space of the processing tank 30 may increase in securing a sufficient flow
passing space at the treated surface side of each of the substrates G.
[0115]
The protrusions 104, 106 of the substrate support units 98, 100 are not limited
to a construction in which they extend only in the vertical direction. For example, a

construction in which the protrusions extend in the horizontal direction as illustrated in
FIG 18, or a construction in which the protrusions extend in a grid form as illustrated in
FIG 19 may also be employed.
[0116]
In the above-described exemplary embodiments, the protrusions 104, 106 of the
substrate support units 98, 100 not only function to retain the substrates G at the rear
side but also function to suppress the flow of dye solution along the rear surfaces of the
substrates G. However, the protrusions 104, 106 may be configured such that they are
not contacted with the rear surfaces of the substrates G, that is, they only have the baffle
function of suppressing the flow of the dye solution along the rear surfaces of the
substrates G without having the function of supporting the substrates.
[0117]
The shapes, configurations and number of the ports provided in the processing
tank 30 may be variously modified. For example, in the above-described exemplary
embodiments, the processing tank 30 is provided with the left upper port 88L, the right
upper port 88R, the left lower port 90L, and the right lower port 90R, and the dye
solution supply units 80, 82 and the flow control units 84, 86 share some or all of these
ports 88L, 88R, 90L, 90R. However, the dye solution supply units 80, 82 and/or the
flow control units 84, 86 may use individual ports, respectively.
[0118]
In the above-described exemplary embodiment, the flow control units 84, 86
are provided separately from the dye solution supply units 80, 82 in order to switch the
flow direction of the dye solution within the processing tank 30. However, the dye
solution supply units 80, 82 may be configured to include the function of the flow
control units 84, 86 or to switch the flow direction of the dye solution within the

processing tank 30 during the processing.
[0119]
The surrounding configuration of the boat 32 may be variously modified. For
example, in order to detachably couple the lift arm 44 of the boat transport unit 34 to the
boat 32 by electromagnetic force, the above-described exemplary embodiments employ
a configuration in which the permanent magnet 42 is attached to the boat 32 and the
electromagnet 46 is attached to the lift arm 44 of the boat transport unit 34. However, in
place of the electromagnetic force, it is possible to employ a configuration in which the
lift arm 44 is coupled to the boat 32 by a mechanical attaching/detaching method.
[0120]
Alternatively, although not illustrated, it is also possible to employ a
configuration in which the lift arm 44 is integrally coupled to the boat 32 and a top
cover fastening unit (not illustrated) is provided to detachably fix the top cover 36 to the
lift arm 44. In such a case, while the boat 32 is being accommodated in the processing
tank together with a predetermined number of substrates G (e.g., 50 substrates) for the
dye adsorption processing, the top opening of the processing tank 30 is closed by the
top cover 36 in a state where the top cover 36 is fixed to the lift arm by the top cover
fastening unit. In addition, when the plurality of substrates G are loaded on or unloaded
from the boat 32 in the outside of the processing tank 30, the top cover fastening unit is
released and then the top cover 36 is retracted on or separated from the lift arm 44.
[0121]
In addition, the above-described exemplary embodiments use the boat 32.
However, as another method, a plurality of substrates may be accommodated in a row
within the processing tank 30 in such a manner that the treated surfaces of the substrates
are parallel to each other. In addition, the substrates may be accommodated in the boat

32 in such manner that the treated surfaces thereof do not face horizontally. For
example, the substrates may be accommodated in the boat such that the treated surfaces
thereof face upward, downward or in any other direction.
[0122]
In addition, the dye solution is supplied in a first direction parallel to the treated
surfaces of the substrates. Then, it is switched to a second direction which is different
from the first direction and parallel to the treated surfaces and the dye solution is
supplied. By switching the dye solution supply direction, the processing time may be
significantly shortened.
[0123]
Further, the above-described exemplary embodiments may be partially
combined with each other and the same effect may be obtained.
[0124]
As described above, the present invention may be suitably applied, especially to
a step of adsorbing a sensitizing dye into a porous semiconductor in a process of
fabricating a dye sensitization solar cell. However, the present invention may be
applied to a processing of adsorbing any dye into any porous semiconductor layer or
any film formed on a treated surface of a substrate.
Description of Symbols
[0125]
10: dye adsorption processing unit
18: transport device
20: dye adsorption unit (dye adsorption apparatus)
26: chuck unit

28: transport driving unit
30: processing tank
32: boat
34: boat transport unit
36: top cover
38a, 38b, 38c: holding unit
44: lift arm
46: electromagnet
72: top cover operating unit
80: first dye solution supply unit
82: second dye solution supply unit
84: first flow control unit
86: second flow control unit
88L: left upper port
88R: right upper port
90L: left lower port
90R: right lower port
98,100: support unit
104: body protrusion
106: cover protrusion
170: controller

WHAT IS CLAIMED IS:
1. A dye adsorption apparatus of adsorbing a dye into a porous semiconductor
layer formed on a treated surface of a substrate, the apparatus comprising:
a boat configured to detachably hold a plurality of substrates which are
arranged in a row such that the treated surfaces of the substrates face horizontally;
a processing tank configured to accommodate the boat and the plurality of
substrates held in the boat to be capable of going in and out of the processing tank
through a top opening;
a top cover configured to close the top opening of the processing tank;
a first transport unit configured to transport the boat into and out of the
processing tank;
a dye solution supply unit configured to supply a dye solution formed by
solving the dye in a solvent into the processing tank to such an extent that the plurality
of substrates held in the boat are sunk in the dye solution within the processing tank;
and
a flow control unit configured to control a flow of the dye solution within the
processing tank during a dye adsorption processing.
2. The dye adsorption apparatus of claim 1, wherein, during the processing,
pressure on the surface of the dye solution in the processing tank covered by the top
cover is higher than atmospheric pressure.
3. The dye adsorption apparatus of claim 1, wherein, during the processing, the
inside of the processing tank covered by the top cover is filled with the dye solution

without a gap.
4. The dye adsorption apparatus of claim 1, wherein the processing tank is
provided with at least one first port and at least one second port,
the dye solution supply unit supplies the dye solution to the processing tank at
least one of the first port and the second port, and
the flow control unit controls the flow of the dye solution using the first port
and the second port.
5. The dye adsorption apparatus of claim 4, wherein the flow control unit
circulates the dye solution between the inside and outside of the processing tank.
6. The dye adsorption apparatus of claim 4, wherein the dye solution supply unit
substitutes old dye solution to new dye solution within the processing tank using the
first port and the second port.
7. The dye adsorption apparatus of claim 4, wherein the flow control unit controls
the flow of the dye solution while substituting old dye solution with new dye solution
within the processing tank using the first port and the second port.
8. The dye adsorption of claim 4, wherein the processing tank is provided with a
third port for use in discharging the dye solution,
the dye solution supply unit substitutes old dye solution with new dye solution
within the processing tank using at least one of the first port and the second port, and
the third port, and

the flow control unit controls the flow of the dye solution while substituting old
dye solution with new dye solution within the processing tank using at least one of the
first port and the second port and the third port.
9. The dye adsorption apparatus of claim 1, wherein, during the dye adsorption
processing, the flow control unit switches or varies the flow direction of the dye
solution.
10. The dye adsorption apparatus of claim 1, wherein, during the dye adsorption
processing, the flow control unit various the flow rate of the dye solution.
11. The dye adsorption apparatus of claim 1, wherein, during the dye adsorption
processing, the flow control unit varies the pressure within the processing tank.
12. The dye adsorption apparatus of claim 1, wherein a flow suppressing section is
provided to suppress the flow of the dye solution along the rear surface of each of the
substrates within the processing tank.
13. The dye adsorption apparatus of claim 12, wherein the flow suppressing section
includes a plurality of flow suppressing members which are arranged in a row with a
spacing corresponding to that of the plurality of substrates arranged in a row and held
on the boat, and provided in the processing tank, and each flow suppressing member
suppresses the flow of the dye solution along the rear surface of a substrate
corresponding to the flow suppressing member.

14. The dye adsorption apparatus of claim 1, wherein, on the boat, the plurality of
substrates are arranged such that the treated surfaces of each pair of adjacent substrates
are opposed to each other.
15. The dye adsorption apparatus of claim 1, wherein the first transport unit
includes an arm detachably coupled to the boat,
the arm breaks away from the arm while the boat is being accommodated in the
processing tank together with the plurality of substrates for a dye adsorption processing,
and
when the boat is transported in the outside of the processing tank, or transported
into or out of the processing tank, the arm is coupled to the boat.
16. The dye adsorption apparatus of claim 1, wherein the first transport unit
includes an arm integrally coupled to the boat,
the top cover is fixed to the arm, and
the top cover closes the top opening of the processing tank the arm while the
boat is being accommodated in the processing tank together with the plurality of
substrates for the dye adsorption processing.
17. The dye adsorption apparatus of claim 1, further comprising a second transport
unit which performs exchange of the plurality of substrates with the first transport unit.
18. A dye adsorption apparatus of adsorbing a dye into a porous semiconductor
layer formed on a treated surface of a substrate, the apparatus comprising:
a processing tank configured to accommodate a plurality of substrates which

are arranged in a row such that the treated surfaces thereof are parallel to each other;
a top cover configured to close a top opening of the tank;
a first transport unit configured to transport the plurality of substrates into or
out of the processing tank; and
a dye solution supply unit configured to supply a dye solution formed by
solving the dye in a solvent into the processing tank to such an extent that the plurality
of substrates held in the boat are sunk in the dye solution within the processing tank,
wherein, during a dye solution processing, a flow direction of the dye solution
within the processing tank is switched by the dye solution unit.
19. A dye adsorption apparatus of adsorbing a dye into a porous semiconductor
layer formed on a treated surface of a substrate, the apparatus comprising:
a processing tank configured to accommodate a plurality of substrates which
are arranged in a row such that the treated surfaces thereof are parallel to each other;
a top cover configured to close a top opening of the processing tank;
a first transport unit configured to transport the plurality of substrates into and
out of the processing tank;
a dye solution supply unit configured to supply a dye solution formed by
solving the dye in a solvent into the processing tank to such an extent that the plurality
of substrates held in the boat are sunk in the dye solution within the processing tank;
and a flow control unit configured to switch a flow direction of the dye solution within
the processing tank during a dye adsorption processing.
20. A dye adsorption method of adsorbing a dye into a porous semiconductor layer
formed on a treated surface of a substrate, the method comprising:

a first step of arranging a plurality of substrates in a row such that the treated
surfaces are parallel to each other and introducing the plurality of substrates into the
processing tank;
a second step of supplying a dye solution formed by solving the dye in a solvent
into the processing tank in a first direction parallel to the treated surfaces; and
a third step of switching to a second direction which is different from the first
direction and parallel to the treated surfaces and supplying the dye solution.