阅读说明：本技术 铜铟镓硒薄膜太阳能电池及制备方法 (Copper indium gallium selenide thin-film solar cell and preparation method thereof ) 是由 许吉林 乔秀梅 梁鹏 刘琦 王权 辛智渊 李静文 付红颖 于 2018-12-25 设计创作，主要内容包括：本发明提供一种铜铟镓硒薄膜太阳能电池及制备方法,所述铜铟镓硒薄膜太阳能电池包括衬底层和依次形成在所述衬底层上的第一电极层、GIGS吸光层和窗口层,所述GIGS吸光层的材料中掺杂有Si；通过在GIGS吸光层的材料中掺杂适量的Si,利用Si起钝化作用,可以有效改善晶粒界面,保证铜铟镓硒薄膜太阳能电池的光电转换率,这样就无需在GIGS吸光层和窗口层之间额外设置缓冲层,从而简化制备工艺、降低生产成本。(The invention provides a copper indium gallium selenide thin-film solar cell and a preparation method thereof, wherein the copper indium gallium selenide thin-film solar cell comprises a substrate layer, a first electrode layer, a GIGS light absorption layer and a window layer which are sequentially formed on the substrate layer, wherein Si is doped in the material of the GIGS light absorption layer; by doping a proper amount of Si in the material of the GIGS light absorption layer and utilizing the passivation effect of the Si, the crystal grain interface can be effectively improved, the photoelectric conversion rate of the CIGS thin-film solar cell is ensured, and thus a buffer layer is not required to be additionally arranged between the GIGS light absorption layer and the window layer, so that the preparation process is simplified, and the production cost is reduced.)

1. The CIGS thin-film solar cell is characterized by comprising a substrate layer, and a first electrode layer, a GIGS light absorption layer and a window layer which are sequentially formed on the substrate layer, wherein Si is doped in the material of the GIGS light absorption layer.

2. The CIGS thin-film solar cell of claim 1, wherein the molar percentage of elements on the surface of the GIGS light-absorbing layer satisfies the following condition: [ Cu ]/([ In ] + [ Ga ] + [ Se ]) is 0.8 to 0.95, and [ Ga ]/([ In ] + [ Ga ] + [ Se ]) is 0.15 to 0.4.

3. The CIGS thin film solar cell of claim 1 or 2, further comprising an anti-reflection layer on a side of the window layer away from the GIGS light absorbing layer and a second electrode layer on a side of the anti-reflection layer away from the window layer.

4. A method for manufacturing a copper indium gallium selenide thin-film solar cell, wherein the method is used for manufacturing the copper indium gallium selenide thin-film solar cell according to any one of claims 1 to 3, and the method comprises the following steps:

depositing a first electrode layer on a substrate layer;

preparing a CIGS light absorption layer on the first electrode layer by adopting a three-step co-evaporation method, wherein Si is doped in the material of the GIGS light absorption layer;

performing light treatment and heat treatment on the GIGS light-absorbing layer in an inert gas environment;

and preparing a window layer on the GIGS light absorption layer by adopting an MOCVD (metal organic chemical vapor deposition) process.

5. The method of claim 4, wherein the step of forming a CIGS light absorbing layer on the first electrode layer using a three-step co-evaporation method comprises:

co-evaporating In, Ga and Se on the first electrode layer;

co-evaporating Cu and Se on the first electrode layer after the steps are finished;

and evaporating a Si source, and co-evaporating In, Ga, Se and Si on the first electrode layer which completes the steps so as to realize the doping of Si In the CIGS light absorption layer.

6. The method as claimed in claim 5, wherein the Si source has a purity in the range of 8-11N and the Si source has an evaporation temperature in the range of 1400-1800 ℃.

7. The method of claim 5, wherein the Si is doped at a concentration in a range of 0.05% to 0.5%.

8. The method of claim 4, wherein the light-treating and heat-treating the GIGS light-absorbing layer comprises:

carrying out heat treatment on the GIGS light absorption layer within the temperature range of 80-100 ℃, and simultaneously carrying out illumination treatment at the illumination intensity of 0.4-0.8 sun; the light irradiation time and the heat treatment time are 100-500 hours.

9. The method of claim 4, wherein the material of the window layer is B-doped ZnO;

the preparation of the window layer on the GIGS light absorption layer by adopting the MOCVD process specifically comprises the following steps:

depositing B-doped ZnO on the CIGS light absorption layer by taking diethyl zinc, water and diborane as raw materials; wherein the deposition temperature range is 140-180 ℃, the flow rates of the diethyl zinc, the water and the diborane are respectively 50-200 mu mol/min, 100-400 mu mol/min and 0.1-0.5 mu mol/min, and the deposition time is 0.5-2.5 hours.

10. The method of any of claims 4-9, wherein after preparing the window layer on the GIGS light absorber layer using the MOCVD process, the method further comprises the steps of:

and sequentially preparing an antireflection layer and a second electrode layer on the window layer by adopting a thermal evaporation process.

Technical Field

The invention relates to the technical field of display, in particular to a copper indium gallium selenide thin-film solar cell and a preparation method thereof.

Background

With the increasing problem of global ecological environment and energy shortage, the worldwide general attention on clean renewable energy sources, especially solar photovoltaic technology, is paid. Among the existing solar cell technologies, the silicon-based solar cell technology is the most mature and the highest market share, but is not the most ideal solar technology due to the preparation process with high energy consumption and high pollution. The CIGS (CIGS for short) thin-film solar cell has the advantages of strong light absorption capacity, long daytime power generation time, good stability, good radiation resistance, high efficiency, low cost, capability of being made into a flexible assembly, most suitable for being used as photovoltaic building integration and the like, gradually receives attention of people, and is a solar cell technology with great development potential.

At present, theoretically, the highest photoelectric conversion efficiency of the CIGS thin-film battery is 33%, and the highest photoelectric conversion efficiency of newly reported laboratories and research and development reaches 22.9%. In order to obtain a copper indium gallium selenide cell with high photoelectric conversion efficiency, a buffer layer is usually added between a CIGS light absorption layer and a window layer, so that lattice mismatch and energy level mismatch between the CIGS light absorption layer and the window layer are reduced, the surface of the CIGS light absorption layer can be protected from being damaged when the window layer is prepared, interface recombination is reduced, and photoelectric conversion efficiency is improved.

The most common material of the buffer layer is cadmium sulfide or zinc sulfide, and the buffer layer is usually prepared by a chemical water bath method, but the wet process and other dry process procedures of battery preparation cannot be achieved, an independent buffer layer deposition step is required, and the process flow and the production cost are increased. The existing CIGS thin-film solar cell has the problem that the interfaces of a window layer, a CIGS light absorption layer and a buffer layer are incompatible, a large number of carrier recombination centers can be generated, and the photoelectric conversion efficiency of the solar cell is seriously influenced.

Disclosure of Invention

The invention provides a copper indium gallium selenide thin-film solar cell and a preparation method thereof aiming at the defects in the prior art, and aims to at least partially solve the problems of how to simplify the preparation process and reduce the production cost on the premise of ensuring the photoelectric conversion rate of the copper indium gallium selenide thin-film solar cell.

In order to solve the technical problems, the invention adopts the following technical scheme:

the invention provides a copper indium gallium selenide thin-film solar cell which comprises a substrate layer, and a first electrode layer, a GIGS light absorption layer and a window layer which are sequentially formed on the substrate layer, wherein Si is doped in the material of the GIGS light absorption layer.

Preferably, the mole percentage of elements on the surface of the GIGS light-absorbing layer satisfies the following condition: [ Cu ]/([ In ] + [ Ga ] + [ Se ]) is 0.8 to 0.95, and [ Ga ]/([ In ] + [ Ga ] + [ Se ]) is 0.15 to 0.4.

Furthermore, the CIGS thin-film solar cell further comprises an anti-reflection layer and a second electrode layer, wherein the anti-reflection layer is positioned on one side, away from the GIGS light absorption layer, of the window layer, and the second electrode layer is positioned on one side, away from the window layer, of the anti-reflection layer.

The invention also provides a preparation method of the copper indium gallium selenide thin-film solar cell, which is used for preparing the copper indium gallium selenide thin-film solar cell and comprises the following steps:

depositing a first electrode layer on a substrate layer;

preparing a CIGS light absorption layer on the substrate layer which is subjected to the steps by adopting a three-step co-evaporation method, wherein Si is doped in the material of the GIGS light absorption layer;

performing light treatment and heat treatment on the GIGS light-absorbing layer in an inert gas environment;

and preparing a window layer on the GIGS light absorption layer by adopting an MOCVD (metal organic chemical vapor deposition) process.

Preferably, the preparation of the CIGS light absorbing layer on the first electrode layer by using a three-step co-evaporation method specifically comprises:

co-evaporating In, Ga, Se on the first motor side;

co-evaporating Cu and Se on the first electrode layer after the steps are finished;

and evaporating a Si source, and co-evaporating In, Ga, Se and Si on the first electrode layer which completes the steps so as to realize the doping of Si In the CIGS light absorption layer.

Preferably, the purity of the Si source is in the range of 8-11N, and the evaporation temperature of the Si source is in the range of 1400-1800 ℃.

Preferably, the doping concentration range of the Si is 0.05% -0.5%.

Preferably, the light irradiation treatment and the heat treatment are performed on the GIGS light absorbing layer, and specifically include:

carrying out heat treatment on the GIGS light absorption layer within the temperature range of 80-100 ℃, and simultaneously carrying out illumination treatment at the illumination intensity of 0.4-0.8 sun; the light irradiation time and the heat treatment time are 100-500 hours.

Preferably, the material of the window layer is ZnO doped with B;

the preparation of the window layer on the GIGS light absorption layer by adopting the MOCVD process specifically comprises the following steps:

depositing B-doped ZnO on the CIGS light absorption layer by taking diethyl zinc, water and diborane as raw materials; wherein the deposition temperature range is 140-180 ℃, the flow rates of the diethyl zinc, the water and the diborane are respectively 50-200 mu mol/min, 100-400 mu mol/min and 0.1-0.5 mu mol/min, and the deposition time is 0.5-2.5 hours.

Further, after the window layer is prepared on the GIGS light-absorbing layer by using the MOCVD process, the method further comprises the following steps:

and sequentially preparing an antireflection layer and a second electrode layer on the window layer by adopting a thermal evaporation process.

According to the CIGS thin-film solar cell and the preparation method thereof, a proper amount of Si is doped in the material of the GIGS light absorption layer, the Si is used for passivation, the crystal grain interface can be effectively improved, the photoelectric conversion rate of the CIGS thin-film solar cell is ensured, and thus a buffer layer is not required to be additionally arranged between the GIGS light absorption layer and the window layer, so that the preparation process is simplified, and the production cost is reduced.

Drawings

Fig. 1 is a schematic structural diagram of a copper indium gallium selenide thin-film solar cell provided by the invention;

fig. 2 is a flow chart of the preparation of the copper indium gallium selenide thin-film solar cell provided by the invention.

Illustration of the drawings:

1. substrate layer 2, first electrode layer 3, GIGS light-absorbing layer

4. Window layer 5, anti-reflection layer 6, second electrode layer

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

As shown in fig. 1, the present invention provides a copper indium gallium selenide thin-film solar cell, which includes: the light-emitting diode comprises a substrate layer 1, and a first electrode layer 2, a GIGS light-absorbing layer 3 and a window layer 4 which are sequentially formed on the substrate layer 1, wherein the material of the GIGS light-absorbing layer 3 is doped with Si. The substrate layer 1 can be a soda-lime glass substrate, the first electrode layer 2 can be made of Mo, the window layer 4 is a transparent electrode TCO, and the material of the window layer can be ZnO or ZnO: B (ZnO doped with B).

By doping a proper amount of Si in the material of the GIGS light absorption layer 3 and utilizing the passivation effect of the Si, the grain interface can be effectively improved, the photoelectric conversion rate of the CIGS thin-film solar cell is ensured, and thus a buffer layer is not additionally arranged between the GIGS light absorption layer 3 and the window layer 4, the preparation process is simplified, and the production cost is reduced.

Preferably, the mole percentage of elements on the surface of the GIGS light-absorbing layer 3 satisfies the following condition: [ Cu ]/([ In ] + [ Ga ] + [ Se ]) is 0.8 to 0.95, and [ Ga ]/([ In ] + [ Ga ] + [ Se ]) is 0.15 to 0.4.

Further, as shown in fig. 1, the cigs thin-film solar cell further includes an anti-reflection layer 5 and a second electrode layer 6, wherein the anti-reflection layer 5 is located on a side of the window layer 4 away from the GIGS light absorption layer 3, the second electrode layer 6 is located on a side of the anti-reflection layer 5 away from the window layer 4, that is, the anti-reflection layer 5 is formed on the window layer 4, and the second electrode layer 6 is formed on the anti-reflection layer 5. One of the first electrode layer 2 and the second electrode layer 6 is a cathode of the copper indium gallium selenide thin-film solar cell, and the other is an anode. The thickness of the antireflection layer 5 is small, and is usually only several tens of nanometers, and after the second electrode layer 6 is formed, the material of the second electrode layer 6 penetrates into the antireflection layer 5.

The invention also provides a preparation method of the copper indium gallium selenide thin-film solar cell, which is used for preparing the copper indium gallium selenide thin-film solar cell and is shown by combining the figure 1 and the figure 2, and the method comprises the following steps:

s1, depositing a first electrode layer 2 on the substrate layer 1.

Specifically, the substrate layer 1 is cleaned before use, and the first electrode layer 2 is deposited on the cleaned substrate layer 1. Preferably, the substrate layer 1 is made of soda lime glass, and the first electrode layer 2 is made of Mo.

And S2, preparing the CIGS light absorption layer 3 on the first electrode layer 2 by adopting a three-step co-evaporation method, wherein the material of the GIGS light absorption layer 3 is doped with Si.

Specifically, Si may be doped in the third step of the three-step co-evaporation method, and the specific implementation manner of the three-step co-evaporation method will be described in detail later. Preferably, the GIGS light absorbing layer 3 has a thickness of 2 to 5 microns.

S3, subjecting the GIGS light absorbing layer 3 to light irradiation treatment and heat treatment in an inert gas atmosphere.

Preferably, the inert gas may be nitrogen or helium. Specifically, the GIGS light-absorbing layer 3 is subjected to heat treatment within the temperature range of 80-100 ℃, and is subjected to light treatment at the illumination intensity of 0.4-0.8 sun, wherein the illumination time and the heat treatment time are 100-500 hours.

S4, preparing a window layer 4 on the GIGS light absorbing layer 3 using the MOCVD process.

Preferably, the material of the window layer 4 is ZnO doped with B (i.e., ZnO: B), and correspondingly, the preparation of the window layer 4 on the GIGS light-absorbing layer 3 by using the MOCVD process specifically includes: depositing B-doped ZnO on the CIGS light absorption layer 3 by using diethyl zinc, water and diborane as raw materials and adopting an MOCVD (metal organic chemical vapor deposition) process; wherein the deposition temperature range is 140-180 ℃, the flow rates of the diethyl zinc, the water and the diborane are respectively 50-200 mu mol/min, 100-400 mu mol/min and 0.1-0.5 mu mol/min, and the deposition time is 0.5-2.5 hours.

It should be noted that the material of the window layer 4 may also be ZnO (not doped with B), and accordingly, diborane is not used as a raw material.

Through the steps, a proper amount of Si is doped in the material of the GIGS light absorption layer 3, the Si is used for passivation, the crystal grain interface can be effectively improved, the photoelectric conversion rate of the CIGS thin-film solar cell is ensured, and therefore a buffer layer does not need to be additionally arranged between the GIGS light absorption layer 3 and the window layer 4, the preparation process is simplified, and the production cost is reduced.

Preferably, the preparation of the CIGS light absorbing layer 3 (i.e., S3) by the three-step co-evaporation method specifically includes the following sub-steps:

s31, co-evaporating In, Ga, and Se on the first electrode layer 2.

Preferably, in this step, the temperature of the substrate layer 1 may be 350 ℃.

S32, co-evaporating Cu and Se on the first electrode layer 2 having completed the above steps.

Preferably, in this step, the temperature of the substrate layer 1 may be 550 ℃.

S33, evaporating Si source, and co-evaporating In, Ga, Se, Si on the first electrode layer 2 where the above steps are completed, thereby achieving doping Si In the GIGS light absorbing layer 3.

Preferably, in this step, the evaporation temperature of the Si source is 1400 ℃ to 1800 ℃, and the temperature of the substrate layer 1 may be 550 ℃.

Preferably, the purity range of the Si source is 8-11N, and the doping concentration range of the Si is 0.05% -0.5%.

Further, as shown in fig. 2, after preparing the window layer 4 on the GIGS light-absorbing layer 3 using the MOCVD process (i.e., S4), the method further includes the steps of:

and S5, preparing the antireflection layer 5 and the second electrode layer 6 on the window layer 4 in sequence by adopting a thermal evaporation process.

In order to clearly illustrate the embodiment of the present invention, the following detailed description is given by means of 4 specific examples.