阅读说明：本技术 一种柔性太阳能电池及其制备方法和应用 (Flexible solar cell and preparation method and application thereof ) 是由 杨文奕 牛文龙 杨云龙 刘建庆 其他发明人请求不公开姓名 于 2021-07-13 设计创作，主要内容包括：本发明公开了一种柔性太阳能电池及其制备方法和应用,属于太阳能电池技术领域。本发明公开的柔性太阳能电池,包括图形化衬底；图形化衬底包括第一表面和第二表面；第一表面上形成有褶皱区；第二表面上设置有电路图案；电路图案,包括导电体以及连接导电体的引线；褶皱区在第二表面上形成的投影,覆盖引线的设置位置。本发明提供的柔性太阳能电池,通过结构设置,能够提升对太阳光的利用率,进而提升柔性太阳能电池的电池组件的效率。(The invention discloses a flexible solar cell and a preparation method and application thereof, and belongs to the technical field of solar cells. The invention discloses a flexible solar cell, which comprises a patterned substrate; the patterned substrate comprises a first surface and a second surface; the first surface is provided with a corrugated area; a circuit pattern is arranged on the second surface; a circuit pattern including a conductor and a lead connected to the conductor; the projection of the fold region formed on the second surface covers the arrangement position of the lead. According to the flexible solar cell provided by the invention, through the structural arrangement, the utilization rate of sunlight can be improved, and the efficiency of a cell module of the flexible solar cell is further improved.)

1. A flexible solar cell, comprising a patterned substrate;

the patterned substrate comprises a first surface and a second surface;

a corrugated area is formed on the first surface;

a circuit pattern is arranged on the second surface;

the circuit pattern comprises a conductor and a lead connected with the conductor;

the projection formed by the fold region on the second surface covers the arrangement position of the lead.

2. The flexible solar cell of claim 1, wherein the substrate is patterned, the raw material for the formation of the flexible layer; preferably, the material of the patterned substrate is at least one of PET and PI; more preferably, the thickness of the flexible layer is 50nm to 200 nm.

3. The flexible solar cell of claim 1, wherein the wrinkled region is formed by at least one of nano-imprinting and photolithography-etching.

4. The flexible solar cell according to any one of claims 1 to 3, further comprising,

a first electrode in contact with the electrical conductor;

an epitaxial layer disposed on the second surface and in contact with the first electrode;

the second electrode is arranged on the surface of one side, away from the patterned substrate, of the epitaxial layer;

and the insulating structure is arranged on the surface of one side, away from the patterned substrate, of the epitaxial layer and is complementary with the arrangement position of the second electrode.

5. The flexible solar cell of claim 4, wherein the insulating structure is made of SiN_x、Al₂O₃、MgF₂At least one of POE and EVA.

6. A method for preparing a flexible solar cell according to any one of claims 1 to 5, comprising the steps of:

s1, forming the fold area on one side of a flexible layer, depositing the electric conductor on the other side of the flexible layer, and reserving the arrangement position of the lead to obtain the graphical substrate;

s2, growing an epitaxial layer on a substrate, and arranging a first electrode matched with the conductor in position on the surface of one side, away from the substrate, of the epitaxial layer;

s3, bonding the part obtained in the step S2 and the patterned substrate obtained in the step S1 by taking the first electrode and the conductor as a bonding point;

s4, removing the substrate of the part obtained in the step S3;

s5, forming an insulating structure on the surface of one side, away from the patterned substrate, of the part obtained in the step S4;

and S6, forming a through hole on the surface of one side, away from the patterned substrate, of the insulating structure, and forming a second electrode in the through hole, wherein the second electrode is complementary with the insulating layer structure in arrangement position, so that the flexible solar cell is obtained.

7. The method according to claim 6, wherein the step S2 further comprises providing a trench in the epitaxial layer perpendicular to the direction of the epitaxial layer after the first electrode is provided; preferably, the trench penetrates through the epitaxial layer to the substrate.

8. The method of claim 6, further comprising providing a dielectric film complementary to the first electrode on the surface of the epitaxial layer on the side away from the substrate between steps S2 and S3.

9. The method according to claim 6, wherein the bonding is performed at a temperature of 150 ℃ to 250 ℃ in step S3; preferably, the bonding is performed under a pressure of 5000N to 20000N.

10. A photovoltaic power supply system, characterized by comprising the flexible solar cell according to any one of claims 1 to 5.

Technical Field

The invention belongs to the technical field of solar cells, and particularly relates to a flexible solar cell and a preparation method and application thereof.

Background

The flexible solar cell is one of thin-film solar cells, has the advantages of advanced technology, excellent performance, low cost and the like, and is widely applied to solar backpacks, solar open canopies, solar flashlights, solar automobiles, solar sailing boats and even solar airplanes.

However, when manufacturing a flexible solar cell, soldering is required, and a lead wire is required to lead out electric energy generated by the flexible solar cell, and since the lead wire is opaque, a part of a light receiving area is lost at a position where the series-parallel lead wire is disposed, thereby reducing the efficiency of the battery module.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art described above. Therefore, the invention provides a flexible solar cell, which can improve the utilization rate of sunlight through structural arrangement, and further improve the efficiency of the flexible solar cell.

The invention also provides a preparation method of the flexible solar cell.

The invention also provides a photovoltaic power supply system with the flexible solar cell.

According to one aspect of the present invention, there is provided a flexible solar cell comprising a patterned substrate;

the patterned substrate comprises a first surface and a second surface;

a corrugated area is formed on the first surface;

a circuit pattern is arranged on the second surface;

the circuit pattern comprises a conductor and a lead connected with the conductor;

the projection formed by the fold region on the second surface covers the arrangement position of the lead.

According to a preferred embodiment of the present invention, at least the following advantages are provided:

when the solar cell is used (including being used independently and being made into a component), the generated current needs to be led out through a lead; the lead can block the sunlight, so the arrangement position of the lead can lose part of the light receiving area of the solar cell, and the efficiency of the solar cell is further reduced; in addition, as more leads are needed in the process of using the solar cells in groups, the efficiency of the solar cell group is lower than that of a single solar cell generally;

in the invention, the corrugated area on the patterned substrate can change the path of light irradiating on the surface of the corrugated area due to the unevenness of the surface; the arrangement position of the lead is covered due to the projection formed by the fold area on the second surface; that is, due to the action of the wrinkle region, sunlight originally blocked by the lead is irradiated to a position near the lead (not blocked), so that the total energy of the solar cell receiving the sunlight is not changed although the light receiving area is still partially lost;

in summary, the patterned substrate of the present invention has, in addition to the conventional supporting function, an electrical output function due to the conductive region and the leads integrated on the second surface; meanwhile, the efficiency of the solar cell is improved due to the arrangement of the fold area.

In some embodiments of the invention, the substrate is patterned, the starting material being a flexible layer.

In some preferred embodiments of the present invention, the flexible layer has a thickness of 50nm to 200 nm.

In some preferred embodiments of the present invention, the flexible layer has a thickness of 200 nm.

In some embodiments of the present invention, the patterned substrate is made of at least one of PET (Polyethylene terephthalate) and PI (Polyimide).

In some embodiments of the invention, the wrinkle region is formed by at least one of a nano-imprinting method and a photolithography etching method.

In some embodiments of the present invention, the conductive body is a Ti layer, a Pt layer, an Au layer, and an Sn layer which are grown in this order from the second surface.

In some preferred embodiments of the present invention, the conductor is a Ti layer having a thickness of 50nm to 100nm, a Pt layer having a thickness of 50nm to 100nm, an Au layer having a thickness of 500nm to 1000nm, and an Sn layer having a thickness of 500nm to 2000nm, which are sequentially grown from the second surface.

In some preferred embodiments of the present invention, the conductive body is a Ti layer having a thickness of 50nm, a Pt layer having a thickness of 50nm, an Au layer having a thickness of 500nm, and an Sn layer having a thickness of 500nm, which are sequentially grown from the second surface.

In some preferred embodiments of the present invention, the flexible solar cell further comprises,

a first electrode in contact with the electrical conductor;

an epitaxial layer disposed on the second surface and in contact with the first electrode;

the second electrode is arranged on the surface of one side, away from the patterned substrate, of the epitaxial layer;

and the insulating structure is arranged on the surface of one side, away from the patterned substrate, of the epitaxial layer and is complementary with the arrangement position of the second electrode.

The complementary meaning is that the surface of the flexible solar cell is divided into two parts, occupied by the insulating structure and the second electrode, respectively.

In some embodiments of the present invention, the flexible solar cell, the epitaxial wafer may exist in a monolithic sheet; the micro battery units can also exist in an array form and correspond to a plurality of micro battery units; the micro-battery cells are at least one of connected in series and in parallel via electrical conductors and leads on the second surface, ultimately forming the flexible solar cell.

In some embodiments of the present invention, the first electrode is a Ti layer, a Pt layer, and an Au layer stacked in this order; the Au layer is in contact with the Sn layer of the conductor.

In some preferred embodiments of the present invention, the first electrode is a Ti layer having a thickness of 50nm to 100nm, a Pt layer having a thickness of 50nm to 100nm, and an Au layer having a thickness of 1000nm to 5000nm, which are sequentially stacked; the Au layer is in contact with the Sn layer of the conductor.

In some preferred embodiments of the present invention, the first electrode is a 50nm Ti layer, a 50nm Pt layer and a 1000nm Au layer stacked in this order; the Au layer is in contact with the Sn layer of the conductor.

In some embodiments of the invention, the epitaxial layer is a GaInP layer and an InGaAs layer sequentially disposed from the first electrode.

In some embodiments of the present invention, the insulating structure is made of SiN_x、Al₂O₃、MgF₂At least one of POE and EVA.

In some embodiments of the present invention, the second electrode is a Ti layer, a Pt layer, and an Au layer stacked in this order; the Ti layer is in contact with the InGaAs layer of the epitaxial layer.

In some preferred embodiments of the present invention, the second electrode is a Ti layer having a thickness of 50nm to 100nm, a Pt layer having a thickness of 50nm to 100nm, and an Au layer having a thickness of 1000nm to 5000nm, which are sequentially stacked; the Ti layer is in contact with the InGaAs layer of the epitaxial layer.

In some preferred embodiments of the present invention, the second electrode is a Ti layer with a thickness of 50nm, a Pt layer with a thickness of 50nm, and an Au layer with a thickness of 1000nm, which are sequentially stacked; the Ti layer is in contact with the InGaAs layer of the epitaxial layer.

When the material of the insulation structure comprises at least one of POE and EVA, the flexible solar cells can be directly connected in series and in parallel to form a flexible solar cell group without a back plate; the reason for this is that the material of the insulating structure can be directly attached to the surface of the region where the solar cell is to be disposed, and the surface of the region where the solar cell is to be disposed can also be used as a support back sheet, so that the flexible solar cell may not be provided with a back sheet.

In some preferred embodiments of the present invention, the patterned substrate is an insulating material, and the insulating structure is also an insulating material, that is, the flexible solar cell obtained by the present invention is already wrapped by the insulating material, and even if the encapsulation process is not performed, there is no risk of electrical leakage, so that the encapsulation step can be omitted;

in addition, in the traditional packaging step, because the thermal expansion coefficients of the packaging material, the battery material, the reserved serial and parallel connection gaps and other components are different, the bending degree of the manufactured flexible solar battery is uncontrollable; according to the flexible solar cell provided by the invention, through the adjustment of the structure, after the packaging step is omitted, the flatness of the flexible solar cell is favorably improved.

According to still another aspect of the present invention, there is provided a method for manufacturing the flexible solar cell, including the steps of:

s1, forming the fold area on one side of a flexible layer, depositing the electric conductor on the other side of the flexible layer, and reserving the arrangement position of the lead to obtain the graphical substrate;

s2, growing an epitaxial layer on a substrate, and arranging a first electrode matched with the conductor in position on the surface of one side, away from the substrate, of the epitaxial layer;

s3, bonding the part obtained in the step S2 and the patterned substrate obtained in the step S1 by taking the first electrode and the conductor as a bonding point;

s4, removing the substrate of the part obtained in the step S3;

s5, forming an insulating structure on the surface of one side, away from the patterned substrate, of the part obtained in the step S4;

and S6, forming a through hole on the surface of one side, away from the patterned substrate, of the insulating structure, and forming a second electrode in the through hole, wherein the second electrode is complementary with the insulating layer structure in arrangement position, so that the flexible solar cell is obtained.

The preparation method according to a preferred embodiment of the present invention has at least the following advantageous effects:

because the flexible solar cell is thin and the supporting force of the flexible substrate is small, dark cracking fragments are easy to occur, so that the problem of low yield rate of electric leakage and the like is caused;

according to the invention, after the epitaxial wafer (including the first electrode) is formed on the substrate, the epitaxial wafer is directly bonded and interconnected to the patterned substrate, and the preparation method avoids the process steps of lacking physical support or low support strength, namely, the battery process is directly carried out on the flexible substrate;

and the physical impact of common welding is avoided by bonding interconnection, so that the probability of fragments is greatly reduced;

therefore, the preparation method provided by the invention can improve the yield of the flexible solar cell.

In some embodiments of the invention, in step S1, the wrinkle region is formed by at least one of a nanoimprint technology and a photolithography and etching technology.

In some embodiments of the present invention, in step S1, the conductive region is disposed by spin-coating a photoresist on the second surface, exposing and developing to reveal the disposed position of the conductive region, and finally forming the conductive region by physical deposition and removing the photoresist used in this step.

In some embodiments of the present invention, in step S2, the substrate is made of GaAs.

In some embodiments of the invention, in step S2, the epitaxial layers are InGaAs layers and GaInP layers grown in sequence from the GaAs layer.

In some embodiments of the present invention, step S2 further includes disposing a contact layer on a surface of the epitaxial layer away from the substrate before disposing the first electrode.

The contact layer is made of GaAs and is used for optimizing ohmic connection between the epitaxial layer and the first electrode.

In some embodiments of the present invention, in step S2, the first electrode is disposed by spin-coating a photoresist on a surface of the epitaxial layer away from the substrate, exposing and developing to reveal a location where the first electrode is disposed, and finally forming the first electrode by using a physical deposition method and removing the photoresist used in this step.

In some embodiments of the present invention, step S2 further includes, after disposing the first electrode, disposing a trench on the epitaxial layer, the trench being perpendicular to the direction of the epitaxial layer.

In some preferred embodiments of the present invention, the trench penetrates the epitaxial layer to the substrate.

In some preferred embodiments of the present invention, the trench is disposed by spin-coating a photoresist on a surface of the epitaxial wafer on a side away from the substrate, exposing and developing to show a location where the trench is disposed, then forming the trench by an ICP dry etching method, and finally removing the photoresist.

After the grooves are arranged, the epitaxial wafers exist in an array mode; that is, after the grooves are arranged, the flexible solar cell is formed, which is actually equivalent to a battery pack formed by connecting a plurality of micro battery units in series and in parallel.

In some preferred embodiments of the present invention, step S2 further includes removing the contact layer except for the first electrode placement position after the trench placement is completed.

The method for removing the contact layer is wet etching, and the etching solution is a mixed aqueous solution of phosphoric acid and hydrogen peroxide.

In some embodiments of the present invention, the method further includes, between steps S2 and S3, disposing a dielectric film complementary to the position of the first electrode on a surface of the epitaxial layer away from the substrate.

In some embodiments of the invention, the dielectric film is SiO₂Layer and MgF₂A composite film formed.

In some preferred embodiments of the present invention, the dielectric film is SiO with a thickness of 50nm to 120nm formed in sequence from a surface of the epitaxial layer away from the substrate₂A layer and MgF having a thickness of 80-150 nm₂And (3) a layer.

In some preferred embodiments of the present invention, the dielectric film is formed from a surface of the epitaxial layer away from the substrateSub-formed SiO with a thickness of 50nm₂Layers and MgF with a thickness of 80nm₂And (3) a layer.

The dielectric film is used as an antireflection film, the reflection effect of the surface of the flexible solar cell on sunlight is reduced, and the sunlight is incident into the cell to the maximum extent.

In some preferred embodiments of the present invention, before step S3, after the composite film is disposed, the method further includes displaying the first electrode again, and specifically includes: and spin-coating photoresist on the surface of the epitaxial layer, exposing and developing to display the arrangement position of the first electrode, and then forming an opening on the dielectric film by adopting an ICP dry etching method to display the first electrode.

In some embodiments of the present invention, in step S3, the bonding temperature is 150 ℃ to 250 ℃.

In some preferred embodiments of the present invention, in step S3, the bonding temperature is 200 ℃.

In some embodiments of the present invention, in step S3, the bonding is performed at a pressure of 5000N to 20000N.

In some preferred embodiments of the present invention, in step S3, the bonding is performed at a pressure of 10000N.

In some embodiments of the present invention, in step S4, the substrate removing method is wet etching.

In some preferred embodiments of the present invention, in step S4, the substrate is removed by using an etching solution of phosphoric acid: hydrogen peroxide: the solution was mixed with water.

In some preferred embodiments of the present invention, in step S4, the substrate is removed by mixing a mixed aqueous solution obtained by mixing phosphoric acid (with a concentration of about 85 wt%), hydrogen peroxide (with a concentration of about 30 wt%) and water in a volume ratio of 1:3: 1.

The part obtained in step S4 is flexible.

In some embodiments of the invention, in step S5, the insulating structure is made of a SiNx thin film and has a thickness of 200nm to 600 nm.

In some embodiments of the invention, in step S5, the insulating structure is made of SiNx thin film and has a thickness of 400 nm.

In some embodiments of the present invention, in step S5, the insulation structure is disposed by at least one of a physical deposition method and a chemical deposition method.

In some preferred embodiments of the present invention, in step S5, the deposition method of the insulating structure is a low temperature chemical deposition method.

In some preferred embodiments of the present invention, in step S6, the via hole is formed by spin-coating a photoresist on a surface of the insulating structure away from the patterned substrate, exposing and developing to form a location where the via hole is to be formed, and then wet etching is used to form the via hole, to expose a portion of the epitaxial layer, and removing the photoresist used in this step.

In some preferred embodiments of the present invention, in step S6, the second electrode is disposed by spin-coating a photoresist on a surface of the through hole, exposing and developing to reveal the disposed position of the second electrode, and then the second electrode is disposed by physical deposition and the photoresist used in this step is removed.

According to a further aspect of the invention, a photovoltaic power supply system comprising said flexible solar cell is proposed.

In some embodiments of the present invention, the photovoltaic power system is used in which the flexible solar cell is disposed with a side surface of the patterned substrate facing sunlight.

Drawings

The invention is further described with reference to the following figures and examples, in which:

FIG. 1 is a schematic structural diagram of a first surface of a patterned substrate obtained in step D2 according to example 1 of the present invention;

FIG. 2 is a schematic structural diagram of a second surface of the patterned substrate obtained in step D2 according to example 1 of the present invention;

FIG. 3 is a schematic structural view of a part obtained in step D3 according to example 1 of the present invention;

FIG. 4 is a schematic structural diagram showing a front view of a part obtained in step D8 in example 1 of the present invention;

FIG. 5 is a schematic structural diagram showing a top view of a part obtained in step D8 in example 1 of the present invention;

fig. 6 is a schematic structural diagram of a bottom view of a flexible solar cell obtained in example 1 of the present invention;

fig. 7 is a schematic structural diagram of a front view of a flexible solar cell obtained in embodiment 1 of the present invention.

Reference numerals:

100. patterning the substrate, 110, the corrugated area, 120, the circuit pattern, 121, the conductor, 122, and the lead;

200. a substrate of GaAs material is formed on a substrate,

300. an epitaxial layer; 310. a first electrode 320, a second electrode;

400. a trench;

500. and an insulating structure.

Detailed Description

The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality is one or more, the meaning of a plurality is two or more, and the above, below, exceeding, etc. are understood as excluding the present numbers, and the above, below, within, etc. are understood as including the present numbers. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

In the description of the present invention, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Example 1

The embodiment prepares the flexible solar cell, and the specific process is as follows:

D1. on one side (first surface) of the PET layer with the thickness of 200 μm, a wrinkle area 110 is formed by adopting a nano-imprinting technology, and the wrinkle area 110 is used as a lens and can change the propagation path of light;

D2. spin-coating a negative photoresist with the model number of L300 on the other side (second surface) of the PET layer, exposing and developing to form a pattern of the conductor, and then sequentially depositing a Ti layer with the thickness of 50nm, a Pt layer with the thickness of 50nm, an Au layer with the thickness of 500nm and a Sn layer with the thickness of 500nm from the PET layer by adopting a physical deposition method to form a conductor 121; a lead 122 is reserved at the position where the lead 122 is arranged, and the lead 122 is connected with the conductor 121 to form a circuit pattern 120; after removing the photoresist used in this step, a patterned substrate 100 is formed;

in the patterned substrate obtained in this step, the schematic structural diagram of the first surface is shown in fig. 1, and the schematic structural diagram of the second surface is shown in fig. 2;

D3. sequentially growing InGaAs layer GaInP layers on the surface of the GaAs substrate 200 to obtain a composite structure of the GaAs substrate 200 and the epitaxial layer 300; a contact layer is grown on the surface of the GaInP layer, and the material of the contact layer is GaAs (not shown in the attached drawing);

the GaAs substrate used in this step has a schematic structure as shown in FIG. 3;

D4. spin-coating a negative photoresist with the model L300 on the surface of the epitaxial layer 300 with the structure obtained in the step D3, exposing and developing to form a pattern of the first electrode 310, then sequentially depositing a Ti layer with the thickness of 50nm, a Pt layer with the thickness of 50nm and an Au layer with the thickness of 1000nm from the epitaxial layer 300 by adopting a physical deposition method, and removing the photoresist used in the step to form the first electrode 310;

D5. spin-coating a positive photoresist with the model AZ4620 on the surface of one side of the epitaxial layer 300 of the component obtained in the step D4, exposing and developing to form a set pattern, and then forming a groove 400 structure by adopting an ICP (inductively coupled plasma) dry etching method to be vertical to the maximum surface of the epitaxial layer, wherein the groove 400 is deep to the GaAs substrate; after removing the photoresist, forming an arrayed epitaxial layer 300; D6. removing the contact layer except the region where the first electrode is arranged by using a mixed aqueous solution of phosphoric acid and hydrogen peroxide as an etching solution (prepared in step D3);

D7. depositing SiO with the thickness of 20nm on the surface of one side of the epitaxial layer 300 of the component obtained in the step D6 by using a physical deposition method₂Layers and MgF 80nm thick₂A layer, the two-layer structure forming a dielectric film (not shown in the drawings due to its small thickness), which functions to reduce the reflectivity of the surface of the cell;

D8. spin-coating a positive photoresist with the type AZ4620 on the surface of the part obtained in the step D7, exposing and developing to form a predetermined pattern, and forming a through hole on the dielectric film by an ICP dry etching method to expose the first electrode 310;

the schematic diagram of the front view of the part obtained in the step is shown in FIG. 4, and the schematic diagram of the top view is shown in FIG. 5;

D9. bonding the component obtained in the step D8 and the component obtained in the step D2, wherein bonding points are the first electrode 310 and the conductor 121, the bonding temperature is 200 ℃, the pressure is 10000N, and an intermediate structure is formed, the upper surface of the intermediate structure is PET, and the lower surface of the intermediate structure is a GaAs substrate 200;

D10. corroding the GaAs substrate 200 of the part obtained in the step D9 by adopting a solution corrosion method, wherein the corrosion solution is a mixed solution prepared by phosphoric acid (about 85 wt%), hydrogen peroxide (about 30 wt%) and water according to a volume ratio of 1:3: 1;

D11. depositing a SiNx insulating structure with the thickness of 400nm on the surface of the part obtained in the step D10, which is far away from the patterned substrate 100, by adopting a low-temperature chemical deposition method;

D12. spin-coating a positive photoresist with the model of AZ4620 on the surface of the part obtained in the step D11, exposing and developing to form a set pattern, forming a through hole on the insulating structure by adopting a wet etching method to expose the epitaxial layer, and removing the photoresist used in the step by adopting an ammonium fluoride solution as an etching solution;

D13. spin-coating a negative photoresist with the model L300 on the surface of the part obtained in the step D12, exposing and developing to form a set pattern, and depositing to form a second electrode 320 by adopting a physical deposition method, wherein the second electrode 320 is a Ti layer with the thickness of 50nm, a Pt layer with the thickness of 50nm and an Au layer with the thickness of 1000nm which are sequentially arranged from an epitaxial layer; and stripping and removing the photoresist to obtain the flexible solar cell.

The structural schematic diagram of the flexible solar cell obtained in this embodiment is shown in fig. 6 in a bottom view, and the structural schematic diagram of the front view is shown in fig. 7.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.