Patent Application
20150179354
The present disclosure relates to solar cells and methods for solar cell manufacture.
Solar cells are photoelectric conversion devices. A low light reflectivity and high absorption of the solar cell is needed to achieve an improved photoelectric conversion efficiency. Dye-sensitized solar cells (DSSCs) have been developed, and are produced using low cost material and do not require complex equipment for their manufacture. DSSCs usually use glass as substrate which is very rigid.
Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the present disclosure.
The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like.
The flexible transparent substrate 10 is transparent and flexible and can be made of plastic or glass. The plastic comprises polyethylene terephthalate (PET) and polyimide (PI) material.
The conductive substrates 211 are made of an electro-conductive material. The electro-conductive material can be a metal or alloy, such as stainless steel, gold, silver, copper, platinum, aluminum, or any combination thereof.
The semiconductor layer 213 is porous and consists essentially of a metal oxide. The metal oxide can be, but is not limited to being, titanium dioxide (TiO2), tin dioxide (SnO2), or zinc oxide (ZnO), or any combination thereof. In the exemplary embodiment, the metal oxide is TiO2.
In the exemplary embodiment, the solar cell units 20 are dye-sensitized solar cells (DSSCs). Each of the working electrodes 21 further comprise photosensitive dye (not shown) absorbed on the semiconductor layers 213.
A transparent and patterned electrode layer 30 is formed on the flexible transparent substrate 10 and is configured to electronically connected to anodes and cathodes of the solar cell units 20. The conductive substrates 211 are electronically connected to the electrode layer 30. The electrode layer 30 can transmit electricity created by the solar cell units 20. The electrode layer 30 is made of a transparent and electro-conductive material selected from a group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum oxide doped zinc, gallium oxide doped zinc oxide, carbon nanotubes, and Mg(OH)2—C. The electrode layer 30 can be formed by depositing a thin film of transparent and electro-conductive material on the surface of the flexible transparent substrate 10 having the solar cell units 20 and then patterning the film to have a desired shape. In the exemplary embodiment, the electrode layer 30 comprises a plurality of wire portions 31 and a plurality of contact portions 32 connected to the wire portions 31. Each of the contact portions 32 has a shape and a size substantially equal to that of the conductive substrates 211. Each of the conductive substrates 211 is in directly contact with one of the contact portions 32.
Each of the solar cell units 20 further comprises a transparent counter electrode 23 and an electrolyte 25 between the working electrode 20 and the transparent counter electrode 23. Each transparent counter electrode 23 is electronically connected to one of the contact portions 32. Sunlight can enter the solar cell units 20 through transparent counter electrode 23.
The solar cell units 20 have such a shape, size, thickness, and a distance between each other that do not degrade the flexibility of the flexible transparent substrate 10 or a light transmitting property of the solar cell 100. Examples of shapes of the solar cell units 20 comprise cylinder and prism such as cuboid. The conductive substrates 211 can have the same single shape or have multiple shapes. As shown in
Referring to
A method for manufacturing the solar cell 100 according to an exemplary embodiment can comprise the following steps.
The plurality of solar cell units 20 are prepared. Preparing the solar cell units 20 comprises the following steps.
The conductive substrates 211 made of metal or alloy are provided.
A colloidal paste is prepared. The colloidal paste comprises said metal oxide, a solvent, and an organic binder. The colloidal paste can be prepared from a colloidal solution of nanoparticles of the metal oxide. The organic binder can be selected from long chain polymers such as ethyl cellulose, polyethylene glycol, or polyvinyl alcohol. The solvent can be selected from alcohols such as ethanol, propanol, or terpineol.
The colloidal paste is applied to a surface of each of the conductive substrates 211.
The conductive substrates 211 coated with the colloidal paste are heated to sinter the metal oxide, thereby creating the porous semiconductor layers 213 on the conductive substrates 211. Traditional sintering is typically carried out by thermal treatment at a temperature of 450° C. to 600° C. for a period of time of at least 30 minutes. In the exemplary embodiment, the conductive substrates 211 are heated to a temperature in a range from about 400° C. to about 500° C. Sintering ensures that the metal oxide particles adhere to each other thereby efficiently carrying current and that they adhere strongly to the conductive substrates. Sintering also ensures complete removal of the organic binder and solvent present in the colloidal paste thereby increasing a porosity of the semiconductor layer 213. During sintering of the metal oxide, the conductive substrates 211 are resistant to damage.
The flexible transparent substrate 10 having the transparent and patterned electrode layer 30 is provided. In one embodiment, the electrode layer 30 is formed by sputtering an ITO film on a surface of the flexible transparent substrate 10 and then etching the ITO film to have a desired pattern shape.
The solar cell units 20 are secured to the flexible transparent substrate 10, to be electronically connected to the contact portions 32 of the electrode layer 30 through the conductive substrates 211. In the exemplary embodiment, the conductive substrates 211 are secured to the flexible transparent substrate 10 by an adhesive.
The embodiments shown and described above are only examples. Many details are often found in the art such as the other features of a solar cell. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, including in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201310705805.1 | Dec 2013 | CN | national |
