Claims:WE CLAIM THAT:

1. Design and working of a solar absorber consisting of a thin sawtooth metasurface nanostructure consisting of graphene monolayer sheet providing a higher absorption characteristic of multiple absorber with the utilization of one graphene layer, reducing the size of the entire device making miniaturization of devices possible.
2. As claimed in claim – 1, the graphene metasurface based solar absorber is provided with artful articulated geometries and sizes with edge adjustment options along with proximity positioning for achieving broadband absorption in Infrared region.
3. As claimed in Claim – 1, the design provided the utilization of only one graphene based broad band absorber that will serve the task of multiple absorber therefore reducing the overall size of the device, so miniaturization of device is possible by this approach with feature of reconfigurability.
4. As claimed in claim – 1, the graphene metasurface based composite layer absorber is designed to absorb incoming electromagnetic radiation in Near Infrared Region where the absorption frequency is dynamically controlled by varying nanostructure parameters and by sheet of graphene which exhibits tremendous application value in the field.
5. As claimed in claim – 1, the sawtooth metasurface nanostructure with graphene monolayer sheet provides an absorption characteristic from 214 THz to 384 THz frequency range. , Description:TITLE
Design and working of a Sawtooth metasurface solar absorber based on graphene monolayer sheet.

FIELD OF THE INVENTION AND USE OF INVENTION

[0001] This invention relates to the field of Electronic Engineering and communication engineering more particularly, a design of solar absorber where graphene metasurface based solar absorber due to which the absorption frequency can be dynamically controlled by varying nanostructure parameters and by sheet of graphene when exhibits tremendous application value in my fields. This design of graphene metasurface based solar absorber will achieve maximum average broadband absorption above 85% in NIR-IR-A range from 214 THz to 384 THz.

PRIOR ART AND PROBLEM TO BE SOLVED

[0002] At present, as " energy-conserving and environment-protective " theory is progressively deep in the minds of people, the clean energy resource as solar energy is got over More to be welcome by everybody. The solar absorber is the part of a solar collector in which the solar radiation is converted into heat. In addition to optical losses, thermal losses also occur in the absorber since it assumes a higher temperature than the environment due to the conversion of the solar radiation into heat. The technical problem lies in the contradictory desire that on the one hand, the absorber should absorb the solar radiation well and on the other hand, should have a low emission of the characteristic radiation. This problem can be solved by means of an optically selective coating that has a threshold wavelength below which the absorption capacity is high and above which the emitted characteristic radiation is low. Such an absorption layer makes use of the fact that the radiation to be absorbed and the emitted characteristic radiation of the absorber to be suppressed have different wavelength ranges.

[0003] This invention provides with a design of a solar absorber which has a sawtooth methasurface nanostructure with graphene monolayer sheet providing an absorption characteristic from 214 THz to 384 THz frequency range. The sawtooth added to single C shaped will help to match impedance with incoming electromagnetic wave. The proposed design provides broadband absorptance which is applicable in energy harvesting and electromagnetic shielding. With this design the overall size of device is also reduced, so miniaturization of device is possible.

THE OBJECTIVES OF THE INVENTION:

[0004] The limited availability of primary energy sources and factors of pollution in the utilization of presently utilized primary energy sources makes considerations of utilization of solar energy desirable.

[0005] It has already been proposed where flat-plate collectors and focusing or concentrating collectors. Each of these types of collectors may be stationary or tracking with respect to its orientation to the angle of incidence of solar radiation. However, high concentration-ratio focusing collectors required for higher temperature heat must be capable of tracking the sun. The collector consists of absorber tube coated with a selective absorber coating on its exterior surface. These absorbers have not been sufficient and efficient to concentrate maximum radiation and in addition tin, indium and certain iron oxide coatings when combined in a tandem arrangement can act as both an absorber and as an infrared mirror, which coatings are relatively easy to apply to a substrate such as glass. On the one hand, tin oxide films have been used for infrared mirrors, but have not as yet been formed as effective absorbers. Iron oxide, however, has been found to be a reasonably good absorber but a poor infrared reflector. and so a rugged, efficient and readily cleanable type absorbed is required to fulfil the requirement

[0006] The principle objective of this invention is a design of a Graphene metasurface based broadband reconfigurable solar absorber which reduces the size of the device along with manufacturing cost.

[0007] Another objective of the invention is that the graphene metasurface based solar absorber is provided with artful articulated geometries and sizes with edge adjustment options along with proximity positioning for achieving broadband absorption in Infrared region.

[0008] The further objective of the invention is that by using one graphene based broad band absorber it will serve the task of multiple absorber therefore reducing the overall size of the device, so miniaturization of device is possible by this approach with feature of reconfigurability.

[0009] The further objective of the invention is that the structure is provisioned with thin graphene metasurface based composite layer absorber to absorb incoming electromagnetic radiation in Near Infrared Region (NIRIR-A).

[0010] The further objective of the invention is that the absorption frequency is dynamically controlled by varying nanostructure parameters and by sheet of graphene which exhibits tremendous application value in the field.

SUMMARY OF THE INVENTION

[0011] A wide variety of solar collectors are presently available, which collectors may be classified into three major types. The first and essentially simplest type of collector is that of the non-tracking flat plate type, which consists essentially of a flat absorber panel enclosed in a collector housing having a window over the absorber, which structure is oriented towards the sun and usually remains fixed in position. This type of structure may be movable for adjustments during the solar year but for the most part it normally remains stationary during any particular period of collection, e.g., day, month, season or year. Another type of collector is that using an evacuated tube or tubes which surrounds an absorber surface. selective absorber coating is an essential component of most efficient collector designs. Existing coatings, although quite efficient, as evidenced by high absorptivity a and low emissivity e, are very expensive. Exotic and expensive materials such as indium, gold and silver compounds are sometimes used to produce spectrally selective absorber surfaces. Considering the square footage requirements of absorber surfaces which are necessary to compete with just the domestic hot water and heating alternatives, such exotic and expensive materials are not economically attractive. This invention provides a Graphene metasurface based broadband reconfigurable solar absorber which is capable of providing the efficiency of multiple absorber with the use of one graphene absorber helping to reduce the overall size of the device making it cost effective. Since graphene is made of carbon, which is abundant and relatively inexpensive material, it offers extraordinarily diverse applications in improving the existing products as well as providing opportunities for developing newer ones. With this design the absorption frequency can be dynamically controlled by varying nanostructure parameters and by sheet of graphene when exhibits tremendous application value in this field.

DETAILED DESCRIPTION OF THE INVENTION

[0012] While the present invention is described herein by way of example, using various embodiments and illustrative drawings, those skilled in the art will recognize that the invention is neither intended to be limited to the embodiment of drawing or drawings described nor designed to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated with specific figures, for ease of illustration, and such omissions do not limit the embodiment outlined in any way. The drawings and detailed description of it are not intended to restrict the invention to the form disclosed, but on the contrary, the invention covers all modification/s, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. The headings are used for organizational purposes only and are not meant to limit the scope of the description or the claims. As used throughout this specification, the worn "may" be used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning, must).

[0013] Further, the words "an" or "a" mean "at least one” and the worn “plurality” means one or more unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents and any additional subject matter not recited, and is not supposed to exclude any other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents acts, materials, devices, articles and the like are included in the specification solely to provide a context for the present invention.

[0014] In this disclosure, whenever an element or a group of elements is preceded with the transitional phrase "comprising", it is also understood that it contemplates the same element or group of elements with transitional phrases "consisting essentially of, "consisting", "selected from the group comprising”, "including", or "is" preceding the recitation of the element or group of elements and vice versa.

[0015] Before explaining at least one embodiment of the invention in detail, it is to be understood that the present invention is not limited in its application to the details outlined in the following description or exemplified by the examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for description and should not be regarded as limiting.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Besides, the descriptions, materials, methods, and examples are illustrative only and not intended to be limiting. Methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention.

[0017] The present invention describes an ultrathin nanostructure, named sawtooth metasurface solar absorber based on graphene monolayer sheet broadband solar absorber in near infrared region. The structure includes graphene, silicon dioxide and tungsten-based C-shaped with added square tooth structure placed above the dielectric layer. The proposed design is analyzed its effect on absorption characteristics from 214 THz to 384 THz frequency range (NIR, IR-A) in term of geometrical parameters. The sawtooth added to single C shaped will help to match impedance with incoming electromagnetic wave. The proposed design provides broadband absorptance which is applicable in energy harvesting and electromagnetic shielding.

[0018] In the designed structure of Graphene based C shaped with sawtooth metasurface broadband solar absorber, the first layer is made of tungsten and the substrate is made with a material of silicon dioxide and the slab below the C-Shape is made up of graphene layer.

[0019] Graphene is considered to be the ‘wonder material’ because of its electrical and mechanical properties. It is the strongest (200 times stronger than steel), thinnest (1 million times thinner than a human hair), most conductive, highly stretchable, extremely transparent, fully flexible, chemically inert and impermeable material. Since graphene is made of carbon, which is abundant and relatively inexpensive material, it offers extraordinarily diverse applications in improving the existing products as well as providing opportunities for developing newer ones. The use of tungsten instead of gold to make graphene metasurface based solar absorber makes the structure cost effective.
[0020] This arrangement helps to obtain absorptivity from 214 THz to 384 THz with more than 75 % absorption and as one graphene based broad band absorber will serve the task of multiple absorber therefore overall size of device is also reduced, so miniaturization of device is possible by this approach with feature of reconfigurability.

FIGURE DESCRIPTION

[0021] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate an exemplary embodiment and, together with the description, explain the disclosed embodiment. In the figures, the left and rightmost digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of the system and methods of an embodiment of the present subject matter are now described, by way of example only, and concerning the accompanying figures, in which:

[0022] Figure – 1 illustrates the diagrammatic view of Graphene based C shaped with sawtooth metasurface broadband solar absorber consisting of Tungsten layer (1), (3), (5) and graphene based thin nanostructure (2) and silicon dioxide layer (5).