CN109786480B

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Info

Publication number: CN109786480B
Application number: CN201910027266.8A
Authority: CN
Inventors: 彭铭曾; 安运来; 郑新和; 卫会云; 刘三姐; 何荧峰; 李美玲; 宋祎萌; 仇鹏; 成佳东
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2019-01-11
Filing date: 2019-01-11
Publication date: 2020-05-12
Anticipated expiration: 2039-01-11
Also published as: CN109786480A

Abstract

Translated fromChinese

本发明涉及太阳能电池技术领域，具体涉及一种纳米阵列结构太阳能电池及其制备方法；所述太阳能电池包括：背电极、纳米阵列结构、附有纳米阵列结构和所述背电极的衬底、设置在所述纳米阵列结构表面的吸光层、填充在所述纳米阵列结构空隙中的填充层、上电极和设置在所述上电极一侧的抗反射涂层；所述背电极设置在所述衬底一面上，所述纳米阵列结构设置在所述衬底另一面；所述上电极设置在所述纳米阵列结构上方，所述抗反射涂层面向所述纳米阵列结构。该纳米阵列结构从阵列周期、直径、高度、纳米阵列顶部结构设计和填充物质等方面进行优化，提高太阳能电池的光电转换效率。

The invention relates to the technical field of solar cells, in particular to a solar cell with a nano-array structure and a preparation method thereof; the solar cell comprises: a back electrode, a nano-array structure, a substrate with the nano-array structure and the back electrode, a set of The light absorption layer on the surface of the nano-array structure, the filling layer filled in the void of the nano-array structure, the upper electrode and the anti-reflection coating arranged on one side of the upper electrode; the back electrode is arranged on the backing On the bottom side, the nano-array structure is arranged on the other side of the substrate; the upper electrode is arranged above the nano-array structure, and the anti-reflection coating faces the nano-array structure. The nano-array structure is optimized from the aspects of array period, diameter, height, nano-array top structure design and filling material, etc., so as to improve the photoelectric conversion efficiency of the solar cell.

Description

Solar cell with nano array structure and preparation method thereof

Technical Field

The invention relates to the technical field of solar cells, in particular to a solar cell with a nano array structure and a preparation method thereof.

Background

A solar cell is a device that converts solar energy into electrical energy by a photoelectric effect or a photochemical effect. In recent years, when non-renewable energy resources such as coal, oil, natural gas and the like are frequently in urgent need and the energy problem increasingly becomes a bottleneck restricting the development of international socioeconomic performance, more and more countries begin to implement the "sunshine plan", advocate the green development concept, and actively develop solar energy resources and seek new power for economic development. While the most mature technology studied at present is silicon-based solar cell, a section of unprocessed silicon solar cell can only absorb 67.4% of sunlight, which means that nearly one third of the sunlight is reflected by the unprocessed silicon solar cell, and from the efficiency point of view, the unrecovered sunlight is wasted, which is also a main obstacle to the development of the solar power station. From the present state of the art, solar cells face two major challenges: the (first) light absorption efficiency is low, resulting in low conversion efficiency. And (II) the cost is higher, and the recovery cost period is longer.

The solar cell with the nano array structure achieves the purpose of improving sunlight absorption by adjusting the nano array structure, the size, the top structure pattern design and the regulation and control of different filling substances, and improves the light conversion efficiency by depositing a wide-bandgap nitride semiconductor light absorption material on the surface of the nano array.

Therefore, a new structure is urgently needed to improve the light absorption efficiency and the conversion efficiency of the silicon-based thin-film solar cell.

Disclosure of Invention

In order to solve the above problems, the present invention provides a solar cell with a nano-array structure and a method for manufacturing the same, wherein the nano-array structure is optimized in terms of array period, diameter, height, nano-array top structure design, filling material, and the like, so as to improve the photoelectric conversion efficiency of the solar cell. The light absorption layer of the solar cell is a wide-bandgap nitride semiconductor material deposited on the surface of the nano array, so that the generation of photon-generated carriers can be enhanced, and the performance of the cell can be improved. The photoelectric conversion efficiency is improved by adjusting the aspects of the nano-array structure, the top structure pattern, the filling material and the like, and the concepts of low energy, environmental protection, greenness and cleanness are realized.

The invention is realized by the following technical scheme:

a nano-array structured solar cell, the solar cell comprising:

a back electrode;

a nano-array structure for reflecting and absorbing sunlight;

a substrate as a carrier for said back electrode and said nano-array structure;

a light absorbing layer for improving the absorption rate of sunlight;

a filling layer for enhancing light scattering;

an upper electrode;

an anti-reflective coating layer;

the nano array structure and the back electrode are respectively arranged on two sides of the substrate; the upper electrode is arranged above the nano array structure, and the anti-reflection coating layer is arranged on one side of the upper electrode facing the nano array structure; the light absorption layer is arranged on the surface of the nano array structure; the filling layer is disposed in the voids of the nano-array structure.

Further, the nano array structure is directly obtained on the substrate through dry etching.

Further, the nano-array structure comprises a nano-array; designing a top structure on the top of the nano array;

the top structure can increase multiple reflection of light among the nano arrays, increase the utilization rate of the light, and improve the reflection and absorption of the light in the nano arrays so as to improve the utilization rate of the light; without the top structure, the sunlight on the top of the nano array structure is directly reflected back and cannot be well utilized.

Further, the nano array is a silicon-based nano array, and the silicon-based nano array refers to a nano array structure which is processed on a silicon-based substrate.

The back electrode is preferably made of a metal material having good conductivity, more preferably Au, Ag, Cu, or the like.

Further, the thickness of the back electrode is 10-300nm, and the preferred thickness is 100 nm.

Further, the substrate material is a conductive substrate, typically a silicon-based, preferably a single crystal P-type Si substrate.

Further, a nano array structure is prepared on the substrate by a dry method or a wet method.

Further, the dry method includes photolithography.

Further, the nano array structure is an array structure of nano columns.

Further, the diameter of the nano-column is 10nm-10 μm, preferably 300 nm;

the height of the nano-column is 100nm-10 μm, preferably 1 μm;

the period of the nano-column is 100nm-10 μm, preferably 1 μm;

the height, the diameter, the period and the like of the nano array structure can be regulated, the nano array is directly prepared on the substrate, the specific surface area (surface area/volume) can be improved structurally, a photon-generated carrier is transmitted along with the radial direction, a transmission path is reduced, and finally the loss of the carrier is reduced.

Further, the period of the nanopillars refers to: the distance between two adjacent nanopillars (i.e., the void length of the nanoarray structure).

Further, the structure top structure pattern design of the nano-pillars can be adjusted and controlled, and the structure of the nano-pillars comprising the top structures is a cylinder and/or a prism, preferably a cylinder.

Further, let a be the perimeter of the upper surface of the top structure, and b be the perimeter of the nano-pillars, and the structure of the top structure is adjustable from a cylinder to a circular truncated cone to a cone or from a diamond to a pyramid according to a set ratio of a/b being greater than or equal to 0 and less than or equal to 1.

Further, the optimal ratio is 0, but the optimal ratio varies according to the incident angle of the sun.

Further, the light absorbing layer is a wide bandgap nitride semiconductor.

Further, the wide bandgap nitride semiconductor includes indium nitride (0.70eV), gallium nitride (3.42eV), aluminum nitride (6.20eV), indium gallium nitride (InxGa1-xN), indium aluminum nitride (InxAl1-xN), aluminum gallium nitride (AlxGa1-xN), and aluminum gallium indium nitride (AlxGayIn 1-x-yN); 0.7eV represents a wavelength of light of about 1800nm, and 6.2eV represents a wavelength of light of about 200 nm; the indium gallium nitride (InxGa1-xN), indium aluminum nitride (InxAl1-xN), aluminum gallium nitride (AlxGa1-xN) and aluminum gallium indium nitride (AlxGayIn 1-x-yN).

Further, the thickness of the light absorbing layer is 10nm to 600nm, preferably 200 nm.

Further, a substance for enhancing nano scattering is filled in the filling layer; the substance for enhancing nano-scattering comprises metal plasma nano-particles and SiO2 nano-particles.

Further, the SiO2 nanoparticles are SiO2 nanospheres with a diameter of 10nm-100nm, preferably 50 nm.

Further, the anti-reflective coating material is a transparent conductive material, which can reduce reflection of light and enhance transmission of light, preferably ZnO, and has a thickness of 5nm to 150nm, preferably 10 nm.

Further, the upper electrode is a transparent electrode, and the transparent electrode can enable sunlight to be refracted on the nano array structure through the electrode; the material is preferably ITO, which can enable the solar light transmittance to be more than 90% and has good conductivity.

Further, the thickness of the upper electrode is 10nm to 500nm, preferably 100 nm.

Furthermore, the nano-array structure is prepared by the photoetching method, and the back electrode and the upper electrode are grown by evaporation methods such as electron beam evaporation or magnetron sputtering.

Further, the light absorbing layer may adopt methods such as chemical vapor deposition, magnetron sputtering, pulsed laser deposition, molecular beam epitaxy, chemical vapor deposition, atomic layer deposition, sol-gel, and electron beam evaporation, preferably atomic layer deposition technology, and when the atomic layer deposition method is adopted to deposit indium nitride, trimethyl indium and N are adopted₂The plasma is used as a precursor, and the deposition temperature is 100-300 ℃; using atomic layer depositionWhen depositing gallium nitride by the product method, triethyl gallium and N are adopted₂The plasma is used as a precursor, and the deposition temperature is 100-350 ℃; when the atomic layer deposition method is adopted to deposit the aluminum nitride, trimethylaluminum and N are adopted₂The plasma is used as a precursor, and the deposition temperature is 100-350 ℃;

when the light absorption layer is deposited on the surface of the nano array structure, the nano array structure has larger depth, and can be uniformly coated on the surface of the nano structure by adopting an atomic layer deposition technology, and the coating rate is more than 97%; by the atomic layer deposition technology, a polycrystalline structure can be grown from indium nitride, gallium nitride and aluminum nitride, and the covered spectral range is from ultraviolet to near infrared.

The invention also provides a preparation method of the solar cell with the nano array structure, which comprises the following steps:

step 1, cleaning and drying a substrate: sequentially performing ultrasonic treatment on the substrate at room temperature by using acetone, absolute ethyl alcohol and deionized water, and drying by using nitrogen;

step 2, sputtering a back electrode: putting the substrate cleaned in the step 1 into a magnetron sputtering chamber, and sputtering a layer of metal material on one surface of the substrate, wherein the layer of metal material is the back electrode;

step 3, preparing a nano array structure: carrying out photoetching treatment on the other surface of the substrate sputtered in the step 2 to obtain the nano array structure;

the photoetching processing steps are as follows:

step 3.1, pretreatment of the substrate: in order to ensure that the photoresist can be well adhered to the surface of the wafer to form a smooth and well-combined film, the surface of the substrate needs to be cleaned and dried to keep the surface dry and clean;

step 3.2, coating photoresist: the aim of gluing is to build a thin, uniform and defect-free photoresist film on the surface of the wafer;

step 3.3, prebaking: the purpose of prebaking is to remove the solvent in the photoresist layer, improve the adhesion of the photoresist and the substrate and the mechanical scratching capability of the photoresist film;

step 3.4, alignment and exposure: the decisive factors for ensuring the normal operation of the device and the circuit are the accurate alignment of the pattern and the formation of the accurate pattern size on the photoresist; after the photoresist is coated, firstly, accurately positioning or aligning a required pattern on the surface of a wafer; then transferring the pattern to the photoresist coating by exposure;

step 3.5, developing: developing means copying a mask pattern onto the photoresist;

step 3.6, post-baking: the developed adhesive film is softened and expanded, and the adhesive force between the adhesive film and the surface of the silicon wafer is reduced;

in order to ensure that the next etching process can be smoothly carried out and the photoresist and the surface of the wafer are better bonded, the solvent must be continuously evaporated to solidify the photoresist;

step 3.7, etching: etching is a process of removing the outermost layer of a wafer through a photoresist exposed area, and the main aim is to accurately transfer patterns on a photoetching mask plate to the surface of the wafer;

and 3.8, removing the photoresist: after etching, the pattern becomes a permanent part of the outermost layer of the wafer; removing the photoresist layer as an etch stop layer from the surface; finally obtaining the nano array structure;

step 4, designing a top structure of the top of the nano column of the nano array structure: carrying out second photoetching treatment on the nano array structure to obtain the top structure;

step 5, cleaning the nano array structure: sequentially putting the nano-array structure prepared in the step 4 into acetone, absolute ethyl alcohol and deionized water for cleaning, then putting the nano-array structure into an HF solution for cleaning, and finally putting the nano-array structure into deionized water for cleaning;

the time for cleaning the nano-array structure in acetone, absolute ethyl alcohol and deionized water for two times is more than 5 minutes respectively;

the volume fraction of the HF solution is 10%; the time for cleaning the nano array structure in the nano array structure is more than 3 minutes;

step 6, depositing a light absorption layer: depositing the surface of the nano array structure cleaned in the step 5 under the conditions of vacuum and constant temperature T to obtain the light absorption layer;

the concrete contents are as follows: putting the cleaned nano array structure in the step 5 into a reaction chamber of a PEALD (plasma enhanced atomic deposition) system, vacuumizing, and then heating to a temperature T and keeping the temperature stable;

the deposition of InN adopts high-purity N respectively₂、H₂And Ar (N)₂:H₂Ar is 3:6:1) and trimethyl indium (TMI) as precursors, and high-purity Ar is used as a purging gas;

the preparation of the InN light absorption layer requires 2500 cycles (cycles) of a thickness of about 200 nm;

the above-mentioned one cycle (cycle) refers to depositing InN once, and depositing InN once needs to be completed sequentially: introducing plasma for reaction for more than 60s, then purging with high-purity Ar for more than 30s, subsequently introducing 0.02s of the trimethyl indium (TMI), reacting for 25s, and then purging for 30 s;

during vacuumizing, vacuumizing to about 0.15Torr and then heating;

keeping the temperature T at 200 ℃ for more than 30min, and then carrying out the next preparation;

step 7, filling a filling layer: filling SiO in the filling layer₂Nanospheres of said SiO₂The diameter of the nanosphere is 50nm, and a semi-formed structure with a back electrode, a substrate, a nano array structure and a light absorption layer is obtained;

step 8, packaging: packaging the upper electrode with the anti-reflection coating on one surface and the semi-forming structure obtained in the step (7) to obtain the solar cell;

the anti-reflection coating is obtained by depositing a transparent conductive material on one surface of the upper electrode by adopting a chemical vapor deposition method.

Further, the working principle of the solar cell is as follows: when sunlight irradiates the upper surface of the upper electrode of the solar cell, reflection and absorption can occur between the nano-array structures after the sunlight penetrates through the ITO and the anti-reflection layer, after the sunlight is captured by the light absorption layer, electrons move to the N region and holes move to the P region after electron hole pairs in the P-N junction obtain photons, and then photoproduction current is generated.

The invention has the following beneficial technical effects:

(1) the nano array structure is optimized in the aspects of array period, diameter, height, nano array top structure design, filling materials and the like, and the photoelectric conversion efficiency of the solar cell is improved.

(2) The light absorption layer of the solar cell is a wide-bandgap nitride semiconductor material deposited on the surface of the nano array, so that the generation of photon-generated carriers can be enhanced, and the performance of the cell can be improved.

(3) The invention can improve the photoelectric conversion efficiency by adjusting the height, the diameter and the period of the nano array structure, and/or adjusting the top structure, and/or adjusting the filling material of the filling layer, and the like, and meets the requirements of low carbon, environmental protection, green and cleanness of energy.

Drawings

Fig. 1 is a schematic structural diagram of a solar cell with a nano-array structure according to an embodiment of the present invention;

FIG. 2 is a schematic top view of a nano-array structure according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a top structure of a nanostructure top shape design in an embodiment of the invention.

Description of reference numerals: 10 is a back electrode; 20 is a nano array structure, 21 is a top structure; 30 is a light absorbing layer; 40 is a filling layer; 50 is an anti-reflective coating; and 60 is an upper electrode.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

On the contrary, the invention is intended to cover alternatives, modifications, equivalents and alternatives which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, certain specific details are set forth in order to provide a better understanding of the present invention. It will be apparent to one skilled in the art that the present invention may be practiced without these specific details.

Example 1

The present embodiment provides a solar cell with a nano-array structure, as shown in fig. 1, the solar cell includes

Aback electrode 10;

a nano-array structure 20 for reflection and absorption of sunlight;

a substrate attached with anano array structure 20 and theback electrode 10, wherein thenano array structure 20 is obtained by etching on the substrate through a dry method or a wet method;

a light absorbing layer 30 for improving the solar light absorption rate, the light absorbing material being a wide bandgap nitride semiconductor material;

afilling layer 40 for enhancing light scattering;

anupper electrode 60;

ananti-reflection coating 50 disposed at one side of the upper electrode;

thenano array structure 20 and theback electrode 10 are respectively arranged on two sides of the substrate; theupper electrode 60 is disposed above the nano-array structure 20, and theanti-reflective coating 50 is disposed on a side of theupper electrode 60 facing the nano-array structure 20; the light absorbing layer 30 is arranged on the surface of thenano array structure 20; thefilling layer 40 is disposed in the voids of the nano-array structure 20.

The nano-array structure 20 comprises a nano-array; designing a top structure on the top of the nano array;

the top structure can increase the reflection of light among the nano arrays, increase the utilization rate of light and improve the absorption of light; without the top structure, the sunlight on the top of the nano array structure is directly reflected back and cannot be well utilized.

Theback electrode 10 is a metal material having good conductivity, preferably Au, Ag, Cu, or the like, and more preferably Au.

The thickness of theback electrode 10 is 10-300nm, preferably 100 nm.

The substrate material is a conductive substrate, preferably a single crystal P-type Si substrate.

The nano-array structure 20 is prepared on the substrate by a dry method or a wet method.

The nano array structure is an array structure of nano columns.

The diameter of the nano-column is in the range of 10nm to 10 μm, preferably 300 nm.

The height of the nanopillars ranges from 100nm to 10 μm, preferably 1 μm.

The period range of the nano-column is 100nm-10 μm, and preferably 1 μm.

The structure of the nanopillars comprising the top structure is a cylinder and/or a prism.

According to the set ratio of a/b being more than or equal to 0 and less than or equal to 1, the structure of the top structure can be regulated and controlled from a nano column to a circular truncated cone and then to a circular cone (nano column) or from a diamond to a pyramid, wherein a is the perimeter of the upper surface of the top structure, and b is the diameter of the bottom surface of the nano column.

The light absorption layer is a wide bandgap nitride semiconductor.

The wide bandgap nitride semiconductor material comprises indium nitride (0.70eV), gallium nitride (3.42eV), aluminum nitride (6.20eV), indium gallium nitride (InxGa1-xN), indium aluminum nitride (InxAl1-xN), aluminum gallium nitride (AlxGa1-xN) and aluminum gallium indium nitride (AlxGayIn 1-x-yN).

The thickness of the light absorption layer is 10nm-600nm, preferably 200 nm.

The filling layer is filled with SiO2 nanospheres, and the diameter of the filling layer is 50 nm.

The anti-reflective coating is a transparent conductive material, can reduce the reflection of light and enhance the transmission of light, and is preferably ZnO, and the thickness of the anti-reflective coating is 5nm-150nm, preferably 10 nm.

The upper electrode material is a transparent electrode, preferably ITO, and the thickness is 100 nm.

The embodiment also provides a preparation method of the solar cell with the nano-array structure, which comprises the following steps:

step 1, cleaning a substrate: sequentially carrying out ultrasonic treatment on the substrate for 5 minutes at room temperature by using acetone, absolute ethyl alcohol and deionized water, and then drying the substrate by using nitrogen; the substrate adopts a double-polishing p-type Si substrate;

step 2, sputtering the back electrode 10: putting the double-polished p-type Si substrate cleaned in the step (1) into a magnetron sputtering chamber, and sputtering a layer of 100nm metal Au on one surface of the double-polished p-type Si substrate, wherein the layer of metal Au is theback electrode 10;

step 3, preparing the nano-array structure 20: carrying out photoetching treatment on the other surface of the double-polished p-type Si substrate plated with theback electrode 10 obtained in the step (2) to obtain thenano array structure 20;

the photoetching processing steps are as follows:

step 3.1, pretreatment of the substrate: in order to ensure that the photoresist can be well adhered to the surface of the wafer to form a smooth and well-combined film, surface preparation is required to be carried out, and the surface is kept dry and clean;

step 3.8, removing the photoresist; after etching, the pattern becomes a permanent part of the outermost layer of the wafer; removing the photoresist layer as an etch stop layer from the surface; the nano-array structure 20 is finally obtained.

The structure of the nano-column prepared by the photolithography method in this example is a cylinder, and the diameter of the cylinder is 300nm, the height is 5 μm, and the period is 1 μm.

Step 4, designing a structure at the top of the nano-column: and performing second photoetching on the nano column, wherein when the diameter b of the nano column is 300nm (namely the diameter of the cylinder) and the photoetching requirement a/b is 0, the structure of the top structure obtained by the second photoetching is conical and has the height of 60 nm.

Step 5, cleaning the nano-array structure 20: and (3) sequentially putting thenano array structure 20 prepared in the step (4) into acetone, absolute ethyl alcohol and deionized water for cleaning for 5 minutes, then putting the nano array structure into a 10% HF solution for cleaning for 3 minutes, and finally putting the nano array structure into deionized water for cleaning for 5 minutes.

Step 6, depositing a light absorption layer: putting the cleaned nano array structure in the step 5 into a reaction chamber of a PEALD (plasma enhanced atomic deposition) system, vacuumizing to 0.15Torr, and then heating to 200 ℃ and keeping the temperature for 30min to stabilize the temperature;

step 8, packaging: packaging the upper electrode with the anti-reflection coating on one surface and the semi-forming structure obtained in the step (7) to obtain the solar cell; the upper electrode adopts a transparent electrode ITO with the thickness of 100 nm;

the anti-reflection coating is obtained by depositing ZnO with the thickness of 10nm on one surface of the upper electrode by adopting a chemical vapor deposition method.

When sunlight irradiates the upper surface of the upper electrode of the solar cell, reflection and absorption can occur between the nano-array structures after the sunlight penetrates through the ITO and the anti-reflection layer, after the sunlight is captured by the light absorption layer, electrons move to the N region and holes move to the P region after electron hole pairs in the P-N junction obtain photons, and then photoproduction current is generated.

Example 2

The present embodiment relates to a solar cell with a nano-array structure and a method for manufacturing the same, which are substantially the same as those in embodiment 1, except that:

the prepared nano-pillar structure is a cylinder, the diameter of the cylinder is 500nm, the height of the cylinder is 5 mu m, and the period of the cylinder is 1.5 mu m.

Example 3

the prepared nano-pillar structure is a cylinder, the diameter of the cylinder is 300nm, the height of the cylinder is 1 mu m, and the period of the cylinder is 1 mu m.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A solar cell with a nano-array structure, the solar cell comprising:

a back electrode;

a nano-array structure for reflecting and absorbing sunlight;

a substrate as a carrier for said back electrode and said nano-array structure;

a light absorbing layer for improving the absorption rate of sunlight;

a filling layer for enhancing light scattering;

an upper electrode;

an anti-reflective coating layer;

the nano array structure and the back electrode are respectively arranged on two sides of the substrate; the upper electrode is arranged above the nano array structure, and the anti-reflection coating layer is arranged on one side of the upper electrode facing the nano array structure; the light absorption layer is arranged on the surface of the nano array structure; the filling layer is arranged in the gap of the nano array structure;

the nano array structure is directly obtained on the substrate through dry etching;

the nano array structure is an array structure of nano columns; designing a top structure on the top of the nano array;

let a be the perimeter of the upper surface of the top structure, b be the perimeter of the nano-pillars, and a/b is more than or equal to 0 and less than or equal to 1;

the diameter of the nano column is 10nm-10 mu m;

the height of the nano column is 100nm-10 mu m;

the period of the nano-column is 100nm-10 mu m;

the light absorption layer is a wide bandgap nitride semiconductor.

2. The solar cell of claim 1, wherein the back electrode material is a metal material.

3. The solar cell with nano-array structure as claimed in claim 1, wherein the anti-reflective coating material is a transparent conductive material with a thickness of 5nm-150 nm.

4. The solar cell with nano-array structure as claimed in claim 1, wherein the structure of the nano-pillars is a cylinder and/or a prism.

5. The method for preparing the solar cell with the nano-array structure according to any one of claims 1 to 4, wherein the method for preparing the solar cell with the nano-array structure specifically comprises the following steps:

step 1, cleaning a substrate and drying;

step 2, sputtering a back electrode: sputtering a layer of metal material on one surface of the substrate, wherein the layer of metal material is the back electrode;

step 4, designing a nano-column top structure of the nano-array structure: carrying out second photoetching treatment on the nano array structure to obtain the top structure;

step 5, cleaning the nano array structure;

step 6, depositing a light absorption layer: depositing the surface of the nano array structure cleaned in the step 5 under the conditions of vacuum and constant temperature to obtain the light absorption layer;

step 7, filling a filling layer: filling a substance for enhancing nano scattering in the filling layer to obtain a semi-formed structure with a back electrode, a substrate, a nano array structure and a light absorption layer;

step 8, packaging: and 7, packaging the upper electrode with the anti-reflection coating on one surface and the semi-forming structure obtained in the step 7 to obtain the solar cell.