DESC:I. Field of the Disclosure:

The present invention relates to a solar cell manufacturing method and a device for fabricating perovskite based solar cell.

II. Background:

Use of solar energy is making world more energy-independent by reducing energy demand and supply gap. With the rise in use of solar energy, devices and techniques utilizing potential of solar energy have also increased. There are several devices that exploit the solar energy. A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity. More often than not, the solar cell or any device harnessing energy is made up of electronic components such as semiconductors.
It is an evident fact that fabrication of any semiconductor device is a complicated process involving very strict ambient conditions. Conventional techniques for fabrication of devices involve a number of different processes for forming the various layers which make up the device. Such processes include: photolithography, vacuum deposition, chemical vapour deposition, oxidation, etching, masking, and dopant diffusion. However, the sheer number of steps in such fabrication makes the manufacturing process slow. In addition, the use of processes such as etching and dopant diffusion which are difficult to accurately control can lead to loss in accuracy in the shape and performance of the finished product.
Printing is another way of fabrication, which utilizes a set of printing processes to create electronic devices on flexible substrates, also known as printed electronics. Printed electronics uses additive processing (i.e. printing) for layer definitions under ambient temperature and pressure conditions compare to subtractive processing used in conventional processing under controlled/vacuum environment. However, existing printing techniques are only capable of printing simple circuits that have low performance. In fact, life cycle of a product manufactured using such techniques is generally low.
Accordingly, there is a need to overcome various existing problems in fabrication industry. For example, there is a need for a fabrication technique that saves time and manpower, while still offers a quality final product.

III. Summary

In light of the above problem, an object of the present disclosure is to provide a system and a method for fabricating perovskite solar cells. The system includes multiple injection members and multiple curing/heating members, wherein the multiple injection members are arranged such that at least one curing/heating member is in between each of the multiple injection members. The multiple injection members may inject ink on a substrate which may get cured instantly by the heat from the at least curing/heating member arranged just after respective multiple injection members. The curing/member may be IR based device. Further, substrate may be continuously moving to receive the ink from the multiple injection members.
In an embodiment, the proposed system may be cost effective due to employment of multiple injection members that may be configured to store different types of material fluids. In addition, the proposed system may utilize controlled dispensing rate of material fluids through the multiple injection members to result in less material wastage.
In another embodiment, the multiple injection members or plurality of dispensers are configured to be fixed parallelly along a first horizontal plane over a moving wafer chuck to result in faster fabrication of the perovskite based solar cells. In fact, due to the unique arrangement of the assembly for fabricating a perovskite based solar cell, overall requirement of space is reduced while the use of multiple injection members results in cost effectiveness. Further, moving wafer chuck enables faster coating while simultaneous IR annealing of layers disposed over the substrate speeds up the fabrication of solar cells.
These aspects of the present disclosure, along with the various features of novelty that characterize the present disclosure, are pointed in the below description. For a better understanding of the present disclosure, its operating advantages, and the specific objects attained by its uses, reference should be made to the accompanying drawing and descriptive matter in which there is illustrated an exemplary embodiment of the present disclosure.

IV. Description of the Drawings:

The advantages and features of the present disclosure will become better understood with reference to the following detailed description taken in conjunction with the accompanying drawings, in which:
Figures 1a – It illustrates an assembly for fabricating a perovskite based solar cell and its operation cycles, in accordance with an exemplary embodiment of the present disclosure;
Fig. 2 illustrates a preferred method of fabricating a perovskite based solar cell, in accordance with an exemplary embodiment of the present disclosure; and
Fig. 3 illustrates an energy band representations of various material fluids of a perovskite based solar cell and a schematic representation of a perovskite based solar cell in accordance with an exemplary embodiment of the present disclosure.

V. Description of the Disclosure:

The exemplary embodiments described herein detail for illustrative purposes are subject to many variations in implementation. The present disclosure provides a method for fabricating a perovskite based solar cell in a cost effective technique due to utilization of plurality of dispensers or syringes. Further, there is disclosed an assembly for fabricating a perovskite based solar cell that operates on less floor area/space due to its unique design. It should be emphasized, however, that the present disclosure is not limited to a method for fabricating a perovskite based solar cell. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but these are intended to cover the application or implementation without departing from the spirit or scope of the present disclosure.
The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.
The terms “having”, “comprising”, “including”, and variations thereof signify the presence of a component.
The present disclosure provides an assembly for fabricating a perovskite based solar cell, as described with reference to Figures 1a – 1f. The assembly 100 may comprise a plurality of dispensers 102, 104, 106, 108, 110 for storing a plurality of material fluids. As illustrated, the plurality of dispensers may be multiple injection members or syringes. The plurality of dispensers may be positioned parallelly along a first horizontal plane. Each of the plurality of dispensers may dispose a different material fluid. For example, the plurality of dispensers may be at least 5 dispensers containing at least one of an Electron Transport Layer (ETL) material fluid, a Mesoporous titanium dioxide (TiO2) material fluid, a Zirconium dioxide (ZrO2) material fluid, a carbon material fluid, and a perovskite material fluid. These plurality of dispensers may form part of a three-dimensional (3D) printing machine.
As illustrated, the assembly for fabricating a perovskite based solar cell may comprise a wafer chuck 112 configured to hold a substrate in a particular position. For example, the substrate may be a Fluorine-doped Tin Oxide (FTO) glass substrate. The wafer chuck 112 may face the plurality of dispensers 102, 104, 106, 108, 110 such that the plurality of material fluids are disposed over and across the substrate while the wafer chuck moves below the plurality of dispensers in a first direction. A plurality of InfraRed (IR) annealing sources 114 or multiple curing/heating members may be placed after each of the plurality of dispensers to expedite fabrication of the perovskite based solar cell.
In an embodiment, the each of the plurality of dispensers may dispose a different material fluid on the substrate positioned over the moving wafer chuck such that a layered fabrication of perovskite based solar cell is obtained, as illustrated in Fig. 1f. For example, a fabrication using conventional machines is a time consuming process because every coating is typically followed by an annealing step, and upon annealing, a next layer is coated; however, in the proposed assembly, an annealing step may be performed between disposition of a different material fluid on the substrate positioned over the moving wafer chuck such that a layered fabrication of perovskite based solar cell 120 is obtained. Therefore, such assembly may be responsible for saving time and manpower during the fabrication of a perovskite based solar cell. In fact, annealing at same time for each step in the proposed assembly may help in continuous processing on larger substrates. Continuous processing in the proposed assembly may save material wastage as compared to conventional machines, where due to a pause in annealing step, results in ink drying and thus ink wastage. The proposed assembly comprising multiple heads, as illustrated in Figures 1a – 1f, results in lower space utilization and lower machinery cost.
In an embodiment, a method for fabricating a perovskite based solar cell is disclosed. The method may comprising steps involved in a flowchart illustrated in Fig. 2. At step 202, a compact titanium dioxide (TiO2) material fluid may be dispensed over a substrate, and the substrate may be annealed at step 204. A Mesoporous titanium dioxide (TiO2) material fluid, a Zirconium dioxide (ZrO2) material fluid, a carbon material fluid, and a perovskite material fluid may be 3D printed over the substrate sequentially at steps 206, 210, 214, 218. At step 220, the substrate may be annealed at a temperature in a range of 50 – 60 degree Celsius to obtain the perovskite based solar cell. In an aspect, at steps 206, 208, 210, the printing is performed using three-dimensional (3D) printing machine comprising a plurality of dispensers storing a plurality of material fluids therein and the plurality of dispensers are positioned parallelly along a first horizontal plane. The substrate may be a Fluorine-doped Tin Oxide (FTO) glass substrate positioned over a wafer chuck that moves below the plurality of dispensers during the fabrication of the perovskite based solar cell.
To highlight the advantages of the present method and proposed assembly in view of existing arts, a fact may be appreciated that it’s very hard to control perovskite infiltration in a layered fabrication stack due to uncontrolled porous architecture. However, in the proposed assembly, it’s very easy to tune porosity by 3D printing, thus perovskite infiltration, at step 218, can be easily controlled. As far as reproducibility is concerned, in the existing fabrication techniques, chances of variation in infiltration, efficiency of solar cells by variation in screen printing paste production batches/supplier is low. While the proposed method and assembly has higher reproducible due to controlled design fabrication by 3D printing.
In an aspect, triple-mesoscopic perovskite solar cells (PSCs) based on architecture of TiO2/ZrO2/Carbon may have high stability and simple fabrication process. The screen-printing technique may enable easy scaling-up of the cell area to mini-modules (10–200 cm2), submodules (200–800 cm2) and modules (=800 cm2).
The foregoing descriptions of specific embodiments of the present disclosure have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present disclosure and its practical application, and to thereby enable others skilled in the art to best utilize the present disclosure and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the present disclosure.
,CLAIMS:We claim:

1. An assembly (100) for fabricating a perovskite based solar cell, the assembly comprising:
a plurality of dispensers (102, 104, 106, 108, 110) for storing a plurality of material fluids and positioned parallelly along a first horizontal plane, wherein each of the plurality of dispensers disposes a different material fluid;
a wafer chuck (112) configured to hold a substrate in a particular position and to face the plurality of dispensers such that the plurality of material fluids are disposed over and across the substrate while the wafer chuck moves below the plurality of dispensers in a first direction; and
a plurality of InfraRed (IR) annealing sources (114) each placed after each of the plurality of dispensers to expedite fabrication of the perovskite based solar cell.
2. The assembly as claimed in claim 1, wherein the plurality of dispensers comprise at least 5 dispensers containing at least one of an Electron Transport Layer (ETL) material fluid, a Mesoporous titanium dioxide (TiO2) material fluid, a Zirconium dioxide (ZrO2) material fluid, a carbon material fluid, and a perovskite material fluid, and wherein the plurality of dispensers form part of a three-dimensional (3D) printing machine.
3. The assembly as claimed in claim 1, wherein the each of the plurality of dispensers disposes a different material fluid on the substrate positioned over the moving wafer chuck such that a layered fabrication of perovskite based solar cell is obtained.
4. The assembly as claimed in claim 1, wherein the substrate is a Fluorine-doped Tin Oxide (FTO) glass substrate.
5. The assembly as claimed in claim 2, wherein the perovskite material fluid is Methylammonium lead Iodide (CH3NH3PbI3) perovskite.
6. A method for fabricating a perovskite based solar cell, the method comprising:
dispensing (202) a compact titanium dioxide (TiO2) material fluid over a substrate, and annealing (204) the substrate at 500 degree Celsius for 30 minutes with a 40 minute ramp rate;
printing a Mesoporous titanium dioxide (TiO2) material fluid (206), a Zirconium dioxide (ZrO2) material fluid (208), a carbon material fluid (210) and a perovskite material fluid (212) over the substrate sequentially; and
annealing (214) the substrate at a temperature in a range of 50 – 60 degree Celsius to obtain the perovskite based solar cell.
7. The method as claimed in claim 6, wherein the printing is performed using three-dimensional (3D) printing machine comprising a plurality of dispensers storing a plurality of material fluids therein and the plurality of dispensers are positioned parallelly along a first horizontal plane.
8. The method as claimed in claim 7, wherein the substrate is a Fluorine-doped Tin Oxide (FTO) glass substrate positioned over a wafer chuck that moves below the plurality of dispensers during the fabrication of the perovskite based solar cell.