Patent Application
20200266307
The present disclosure relates to a solar cell and a method of manufacturing the same, and more particularly to a high efficiency solar cell with lightweight support structure and a method of manufacturing the same.
In solar cells industry, among the wide range of semiconductor materials for solar cells currently under intensive study, those using Group III-V compound semiconductor materials have exhibited the highest efficiencies. Moreover, Group III-V multi junction solar cells have experienced vast improvements in efficiency over decades of technological progress. The substrate material should be selected to be lattice-matched to the deposited semiconductor material. For example, Group III-V multi junction solar cells may be grown on a Ge or GaAs substrate that is lattice-matched to the deposited Group III-V semiconductor alloy materials of the device.
However, many of the substrate materials, such as GaP, GaAs, GaAsP, and InAs, that are lattice-matched to desirable Group III-V semiconductor materials may be relatively rare or prohibitively expensive, or may be difficult to obtain or produce in large quantities or suitable sizes. Also, these substrates are relatively heavy and thick, thereby hindering their commercialization.
Accordingly, it is necessary to provide Group III-V compound semiconductor solar cells with low-cost, lightweight, and high efficiency to solve the technical problems in the prior art.
In order to solve the above-mentioned technical problems, an object of the present disclosure is to provide a high efficiency solar cell with lightweight support structure, in which a Group III-V photoelectric conversion structure is disposed on a lightweight and flexible composite substrate. Also, a Group III-V based substrate could be recycled for the next usage as a growth template, thereby obtaining Group III-V compound semiconductor solar cells with low-cost and lightweight. Moreover, since the composite substrate includes an optical reflective layer, it enhances efficiency by enabling photon recycling.
In order to achieve the above object, the present disclosure provides a solar cell with lightweight support structure, including: a composite substrate; a photoelectric conversion structure disposed on the composite substrate, and including a light receiving side and a back side which is opposite the light receiving side; a front electrode formed on the light receiving side; and a back electrode formed on the back side, where the composite substrate includes an optical reflective layer which is connected with the back side of the photoelectric conversion structure; and where the photoelectric conversion structure includes at least one Group III-V compound semiconductor layer.
In one preferable embodiment of the present disclosure, the composite substrate includes a polymer support substrate and the optical reflective layer which is disposed on the polymer support substrate.
In one preferable embodiment of the present disclosure, the polymer support substrate is flexible.
In one preferable embodiment of the present disclosure, the at least one Group III-V compound semiconductor layer is selected from a group consisting of a GaAs layer, an InGaP layer, and an InGaAs layer.
In one preferable embodiment of the present disclosure, the back electrode partially covers the back side of the photoelectric conversion structure.
In one preferable embodiment of the present disclosure, a material of the optical reflective layer is selected from the group consisting of aluminum and silver.
In one preferable embodiment of the present disclosure, a surface of the optical reflective layer adjacent to the photoelectric conversion structure is a textured surface for light trapping.
In one preferable embodiment of the present disclosure, the solar cell further includes an adhesive layer disposed between the photoelectric conversion structure and the composite substrate.
In one preferable embodiment of the present disclosure, the optical reflective layer itself is adhesive, such that the photoelectric conversion structure is adhered to the composite substrate by the optical reflective layer.
Another object of the present disclosure is to provide a method of manufacturing a solar cell with lightweight support structure, including: forming a photoelectric conversion structure, where the photoelectric conversion structure includes a light receiving side and a back side which is opposite the light receiving side; providing a composite substrate; and disposing the photoelectric conversion structure on the composite substrate, where the composite substrate includes an optical reflective layer which is connected with the back side of the photoelectric conversion structure; and where the photoelectric conversion structure includes at least one Group III-V compound semiconductor layer.
In one preferable embodiment of the present disclosure, the step of forming the photoelectric conversion structure includes: providing a Group III-V based substrate; forming a sacrificial layer on the Group III-V based substrate; and growing the photoelectric conversion structure on the sacrificial layer.
In one preferable embodiment of the present disclosure, the step of disposing the photoelectric conversion structure on the composite substrate includes: transferring the photoelectric conversion structure onto the composite substrate from the Group III-V based substrate.
In one preferable embodiment of the present disclosure, the step of disposing the photoelectric conversion structure on the composite substrate includes: disposing the Group III-V based substrate with the sacrificial layer and the photoelectric conversion structure on the composite substrate, where the photoelectric conversion structure is contacted with the composite substrate; separating the Group III-V based substrate from the photoelectric conversion structure by removing the sacrificial layer.
In one preferable embodiment of the present disclosure, the step of growing the photoelectric conversion structure on the sacrificial layer includes: sequentially growing an InGaP layer, a GaAs layer, and an InGaAs layer on the sacrificial layer.
In one preferable embodiment of the present disclosure, a material of the sacrificial layer includes AlAs.
In one preferable embodiment of the present disclosure, the method further includes: forming a front electrode on the light receiving side; and forming a back electrode on the back side, where the back electrode partially covers the back side of the photoelectric conversion structure.
In one preferable embodiment of the present disclosure, the step of disposing the photoelectric conversion structure on the composite substrate includes: disposing an adhesive layer on the composite substrate, and connecting the photoelectric conversion structure with the composite substrate by the adhesive layer.
In one preferable embodiment of the present disclosure, the optical reflective layer itself is adhesive, such that after disposing the photoelectric conversion structure on the composite substrate, the photoelectric conversion structure is adhered to the composite substrate by the optical reflective layer.
In the solar cell of the present disclosure, a photoelectric conversion structure is transferred onto a lightweight and flexible composite substrate from a Group III-V based substrate where the photoelectric conversion structure is grown on, such that the removed Group III-V based substrate can be recyclable for the next usage as a growth template. Furthermore, since the composite substrate includes an optical reflective layer, it enhances efficiency by enabling photon recycling. Therefore, a light-absorption of the solar cell at wavelengths below 600 nm can be increased.
In order to more clearly describe the technical solutions of the embodiments of the present disclosure, accompanying drawings to be used in the detailed description of the disclosure will be briefly described hereinbelow. Obviously, the accompanying drawings described hereinbelow only illustrate some of the embodiments of the present disclosure, and those of ordinary skill in the art can also obtain other accompanying drawings therefrom without the need of making inventive efforts.
The following clearly and completely describes the technical solutions in the embodiments of the present disclosure with reference to the accompanying drawings in the embodiments of the present disclosure. Apparently, the embodiments to be described are merely part rather than all of the embodiments of the present disclosure. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.
Refer to
After the Group III-V based substrate 11 is provided, as shown in
Additionally, the photoelectric conversion structure 13 includes a light receiving side S1 for receiving sunlight and a back side S2 which is opposite the light receiving side S1. As shown in
After the photoelectric conversion structure 13 is formed, the photoelectric conversion structure 13 is transferred onto a composite substrate 15 from the Group III-V based substrate 11. In one exemplary embodiment, the transferring steps are described as follow.
As shown in
As shown in
After disposing the photoelectric conversion structure 13 on the composite substrate 15, as shown in
After removing the Group III-V based substrate 11, as shown in
Refer to
Refer to
As shown in
In the solar cell of the present disclosure, a photoelectric conversion structure is transferred onto a lightweight and flexible composite substrate from a Group III-V based substrate where the photoelectric conversion structure is grown on, such that the removed Group III-V based substrate can be recyclable for the next usage as a growth template, thereby reducing the manufacture cost. Furthermore, since the composite substrate includes an optical reflective layer, it enhances photoelectric efficiency.
The above descriptions are merely preferable embodiments of the present disclosure, and are not intended to limit the scope of the present disclosure. Any modification or replacement made by those skilled in the art without departing from the spirit and principle of the present disclosure should fall within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure is subject to the appended claims.
