阅读说明：本技术 一种新型银铅硅硫硒薄膜光伏吸收层材料及其制备方法 (Novel silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material and preparation method thereof ) 是由 齐亚芳 赵晓月 周文辉 周正基 寇东星 武四新 于 2021-08-31 设计创作，主要内容包括：一种新型的银铅硅硫硒薄膜光伏吸收层材料的制备方法,包括以下步骤：1)配制溶剂混合液；2)制备前驱体溶液；3)Ag-(2)PbSiS-(4)前驱体薄膜的制备,在氩气气氛下,将Ag-(2)PbSiS-(4)前驱体溶液在钙钠玻璃上旋涂预烧得Ag-(2)PbSiS-(4)前驱体薄膜；4)Ag-(2)PbSi(S,Se)-(4)吸收层薄膜的制备将Ag-(2)PbSiS-(4)前驱体薄膜在氩气气氛下高温退火硒化,硒化后,在氩气气氛中冷却至室温,得Ag-(2)PbSi(S,Se)-(4)吸收层薄膜。本发明首次提出Ag-(2)PbSi(S,Se)-(4)材料的制备方法,将Ag-(2)PbSi(S,Se)-(4)材料从理论推导到实际应用,使其不再仅仅局限在理论计算阶段,制备的Ag-(2)PbSi(S,Se)-(4)材料表面致密均匀。(A preparation method of a novel silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material comprises the following steps: 1) preparing a solvent mixed solution; 2) preparing a precursor solution; 3) ag 2 PbSiS 4 Preparing precursor film by reacting Ag in argon atmosphere 2 PbSiS 4 The precursor solution is spin-coated and presintered on the calcium sodium glass to obtain Ag 2 PbSiS 4 A precursor film; 4) ag 2 PbSi(S,Se) 4 Preparation of absorbing layer film Ag 2 PbSiS 4 Annealing and selenizing the precursor film at high temperature in argon atmosphere, cooling to room temperature in argon atmosphere after selenizing to obtain Ag 2 PbSi(S,Se) 4 And (5) an absorption layer film. The invention firstly proposes Ag 2 PbSi(S,Se) 4 A method for preparing the material, Ag 2 PbSi(S,Se) 4 The material is deduced from theory to practical application, so that the material is not limited to the Ag prepared in the theoretical calculation stage 2 PbSi(S,Se) 4 The surface of the material is compact and uniform.)

1. A preparation method of a silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material is characterized by comprising the following steps:

preparing solvent mixed liquor

According to the volume ratio (3-5): (2-4): (1.5-3) respectively weighing absolute ethyl alcohol, 1-n-butylamine and carbon disulfide, and mixing the solvents to obtain a solvent mixed solution;

preparation of precursor solution

According to the metering ratio Ag: pb: si = (3-5): (1.5-3): (1.5-3) respectively weighing silver acetate, lead oxide and tetraethyl silicate, and mixing the silver acetate (C)₂H₃O₂Ag), lead oxide (PbO), tetraethyl silicate (C)₈H₂₀O₄Si) is sequentially added into the solvent mixed solution in the step 1) to be dissolved to obtain silver, lead, silicon and sulfur (Ag)₂PbSiS₄) A molecular precursor solution;

Ag₂PbSiS₄preparation of precursor film

Under argon atmosphere, Ag₂PbSiS₄The precursor solution is subjected to multiple spin coating and presintering treatments on calcium sodium glass sputtered with a molybdenum (Mo) back contact layer of 700-900 nm to obtain silver-lead-silicon-sulfur (Ag) with the thickness of 1.8-2.2 mu m₂PbSiS₄) A precursor film;

Ag₂PbSi(S,Se)₄preparation of film of absorbing layer

Mixing Ag with water₂PbSiS₄Annealing and selenizing the precursor film at high temperature in argon atmosphere, and cooling to room temperature to obtain Ag-Pb-Si-S-Se (Ag)₂PbSi(S,Se)₄) And (5) an absorption layer film.

2. The method for preparing the silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material as claimed in claim 1, wherein in the step 1), the ratio of the amount of absolute ethyl alcohol to the amount of 1-n-butylamine is (1-2): 1.

3. the method for preparing the silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material as claimed in claim 1, wherein in the step 1), magnetic stirring and mixing are adopted, the stirring speed is 1000 rpm-1200 rpm, and the stirring time is 10 min-20 min.

4. The method for preparing the silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material as claimed in claim 1, wherein in the step 2), the charging sequence of the materials is as follows: firstly, silver acetate (C)₂H₃O₂Ag) is added into the solvent mixed solution prepared in the step 1), and is magnetically stirred for 2 to 3 hours at the rotating speed of 1100 to 1300 rpm at the temperature of between 40 and 55 ℃ for dissolution; adding lead oxide (PbO) into the system, continuously magnetically stirring at 1100-1300 rpm at 40-55 ℃ for 1-2 h for dissolving, and then adding tetraethyl silicate (C) into the system₈H₂₀O₄Si) is dissolved at 40-55 ℃ by magnetic stirring at the rotating speed of 1100-1300 rpm for 2-3 h.

5. The method for preparing the silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material as claimed in claim 1, wherein in the step 3), the specific operations of spin coating and presintering each time are as follows: spin coating at 2000-3000 rmp for 20-30 s to obtain film, and pre-sintering at 200-300 deg.c for 1-3 min.

6. The method for preparing the silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material as claimed in claim 1, wherein in the step 3), spin coating and pre-sintering treatment are carried out for 6-8 times; the calcium sodium glass is sputtered with a Mo back contact layer of 700 nm-900 nm.

7. The method for preparing the silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material as claimed in claim 1, wherein in the step 4), Ag is firstly added₂PbSiS₄And placing the precursor film in a square stone cartridge containing 400-500 mg selenium grains, and annealing and selenizing at high temperature in an argon atmosphere.

8. The method for preparing the silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material as claimed in claim 1, wherein in the step 4), the high-temperature annealing selenization process is carried out under normal pressure, the selenization temperature is 350 ℃ to 550 ℃, the selenization time is 15 to 40 min, the heating rate is 7 °/s to 10 °/s, the argon flow rate is 40 mL/min to 60 mL/min, and after selenization, the photovoltaic absorption layer material is cooled to room temperature in an argon flowing atmosphere.

9. The silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material prepared by the method of any one of claims 1 to 8.

Technical Field

The invention belongs to the technical field of photovoltaic absorption layers, and particularly relates to a novel silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material and a preparation method thereof.

Background

Chalcogen semiconductors play an important role in photovoltaic and energy related applications, including photovoltaics, thermoelectrics, batteries, transistors, photonic and phase change memory devices, and the like. More successful examples of these include commercial blende cadmium telluride and chalcopyrite copper indium gallium selenide, which have achieved high power conversion efficiencies in photovoltaic devices. But the abundance of tellurium and indium elements is relatively low, which hinders the further development of these technologies. Kesterite-based copper-zinc-tin-sulfur-selenium (Cu)₂ZnSn(S,Se)₄) Has a similar crystal structure with the copper indium gallium selenide and is considered as an ideal substitute for the next generation of photovoltaic materials. Despite the initial advances, the efficiency is currently only 12.7%, which is still far below that of cadmium telluride and copper indium gallium selenide (> 20%). The essential reason for the performance gap is the ionic size and coordination similarity of copper/zinc/tin and the related element disorder, resulting in severe band tail and high concentration of deep level defects.

Therefore, the development of a novel silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material and a preparation method thereof have necessary significance.

Disclosure of Invention

The invention aims to provide a preparation method of a novel silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material, so as to inhibit the formation of defects in a solar cell absorption layer and further improve the photoelectric conversion efficiency of a solar cell.

In order to realize the purpose, the invention adopts the following technical scheme: a preparation method of a novel silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material comprises the following steps:

1) preparing solvent mixed liquor

According to the volume ratio (3-5): (2-4): (1.5-3) respectively weighing absolute ethyl alcohol, 1-n-butylamine and carbon disulfide, and mixing the solvents to obtain a solvent mixed solution;

2) preparation of precursor solution

According to the metering ratio Ag: pb: si = (3-5): (1.5-3): (1.5-3) respectively weighing silver acetate, lead oxide and tetraethyl silicate, and mixing the silver acetate (C)₂H₃O₂Ag), lead oxide (PbO), tetraethyl silicate (C)₈H₂₀O₄Si) is sequentially added into the solvent mixed solution in the step 1) to be dissolved to obtain silver, lead, silicon and sulfur (Ag)₂PbSiS₄) A molecular precursor solution;

3）Ag₂PbSiS₄preparation of precursor film

Under argon atmosphere, Ag₂PbSiS₄The precursor solution is spin-coated and presintered on the calcium sodium glass for a plurality of times to obtain silver, lead, silicon and sulfur (Ag) with the thickness of 1.8-2.2 mu m₂PbSiS₄) A precursor film; the reason for selecting the soda-lime glass is that the sodium in the soda-lime glass can effectively promote grain growth in the subsequent selenization process.

4）Ag₂PbSi(S,Se)₄Preparation of film of absorbing layer

Mixing Ag with water₂PbSiS₄Annealing and selenizing the precursor film at high temperature in argon atmosphere, and cooling to room temperature to obtain Ag-Pb-Si-S-Se (Ag)₂PbSi(S,Se)₄) And (5) an absorption layer film.

In the step 1), the dosage ratio of the absolute ethyl alcohol to the 1-n-butylamine is (1-2): 1.

in the step 1), magnetic stirring is adopted for mixing, the stirring speed is 1000 rpm-1200 rpm, and the stirring time is 10 min-20 min.

In the step 2), the material feeding sequence is as follows: firstly, silver acetate (C)₂H₃O₂Ag) is added into the solvent mixed solution prepared in the step 1), and is magnetically stirred for 2 to 3 hours at the rotating speed of 1100 to 1300 rpm at the temperature of between 40 and 55 ℃ for dissolution; adding lead oxide (PbO) into the system, continuously magnetically stirring at 1100-1300 rpm at 40-55 ℃ for 1-2 h for dissolving, and then adding tetraethyl silicate (C) into the system₈H₂₀O₄Si) at 40 ℃ to 55 ℃ at a rotation speed of 1100 rpm to 1300 rpmStirring for 2-3 h by fast magnetic force to dissolve.

In the step 3), the specific operations of spin coating and presintering at each time are as follows: spin coating at 2000-3000 rmp for 20-30 s to obtain film, and pre-sintering at 200-300 deg.c for 1-3 min.

In the step 3), spin coating and pre-sintering are carried out for 6-8 times; the calcium sodium glass is sputtered with a Mo back contact layer of 700 nm-900 nm.

In step 4), Ag is firstly added₂PbSiS₄And placing the precursor film in a square stone cartridge containing 400-500 mg selenium grains, and annealing and selenizing at high temperature in an argon atmosphere.

In the step 4), the high-temperature annealing selenization process is carried out under normal pressure, the selenization temperature is 350-550 ℃, the selenization time is 15-40 min, the heating rate is 7-10 DEG/s, the argon flow rate is 40-60 mL/min, and after selenization, the high-temperature annealing selenization process is cooled to the room temperature in the flowing atmosphere of argon.

The photovoltaic absorption layer material of the silver-lead-silicon-sulfur-selenium film prepared by the method.

In the present invention, though theoretically Ag₂PbSi(S,Se)₄The quaternary compound is an ideal solar cell absorption layer material, but because the Si simple substance and the salt thereof are extremely difficult to dissolve in water or organic solvent, the Ag is prepared by utilizing a simple and low-cost molecular precursor solution method₂PbSi(S,Se)₄Thin films of the absorbing layer are difficult to achieve. According to the invention, by utilizing the characteristic that tetraethyl silicate is easily miscible with absolute ethyl alcohol, a liquid-phase organic compound tetraethyl silicate is firstly dissolved in a mixed system of absolute ethyl alcohol, 1-n-butylamine and carbon disulfide, and research shows that in the mixed solvent system, when the dosage ratio of absolute ethyl alcohol to 1-n-butylamine is (1-2): 1 hour, prepared Ag₂PbSiS₄The molecular precursor solution is more stable and uniform, and the surface of the prepared absorption layer film is compact and uniform.

Compared with the prior art, the invention has the following technical effects:

1) firstly put forward Ag₂PbSi(S,Se)₄A method for preparing the material, Ag₂PbSi(S,Se)₄Material fromThe theory is derived to practical application, so that the method is not limited to the theoretical calculation stage any more, and the method is a qualitative crossover;

2) as can be seen from the XRD pattern, the obtained absorption layer film is mostly Ag₂PbSi(S,Se)₄Phase (1); as seen from the SEM image, the surface of the absorption layer film is compact and uniform; this indicates that the resulting thin film is suitable as an absorber layer material for solar cells.

Drawings

FIG. 1 (a) Ag₂PbSiS₄Precursor solution; (b) ag₂PbSiS₄Thermogravimetric analysis of the precursor solution; (c) ag₂PbSiS₄Surface SEM image of the precursor film; (d) ag₂PbSiS₄A cross-sectional SEM image of the precursor film;

FIG. 2(a) Ag after pre-firing on a hot stage at 250 deg.C₂PbSiS₄Precursor film, and Ag selenized at 350 deg.C, 400 deg.C and 500 deg.C₂PbSi(S,Se)₄XRD pattern of the film; ag selenized at (b)350 ℃, (c)400 ℃ and (d)500 ℃₂PbSi(S,Se)₄Surface SEM image of the film;

FIG. 3 is a photograph of stability tests of the present invention and comparative example;

FIG. 4 is an SEM image of the present invention and comparative example.

Detailed Description

The present invention will be specifically illustrated by the following examples, but these specific embodiments do not limit the scope of the present invention in any way.

Experimental example 1

A preparation method of a novel silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material comprises the following steps:

1) preparing a solvent mixed solution:

a25 ml sample bottle was charged with 3ml of absolute ethanol, 3ml of 1-n-butylamine and 2.5ml of carbon disulfide (CS)₂) Then stirring on a magnetic stirring electric heating sleeve for 10 min to obtain a uniformly mixed solution; the stirring speed is 1000 rpm;

2) preparing a precursor solution:

according to the stoichiometric ratio (i.e. Ag: Pb: Si =2: 1)Element proportion of 1) to prepare a molecular precursor solution. Firstly, weighing a certain amount of silver acetate C₂H₃O₂Ag) was added to the above sample vial, and the vial was then placed in a magnetic heating mantle and heated and stirred at 1200 rpm for 2h at 40 ℃ until all the solids had dissolved. Then, a certain amount of lead oxide (PbO) was weighed into the sample bottle, and heating and stirring were continued at 40 ℃ for 1 hour. After all the solids had dissolved, a quantity of tetraethyl silicate was drawn into the sample vial using a 1ml needle and heated with stirring at 40 ℃ for 3 h. Finally obtaining clear and transparent orange silver lead silicon sulfur (Ag)₂PbSiS₄) Molecular precursor solution (fig. 1 a).

During the solution preparation process, the solvent carbon disulfide is used as a sulfur source to provide sulfur element for the solution. All procedures during solution preparation were performed in an open fume hood. The precursor solution has stable property, and the stable period is about one month.

3）Ag₂PbSiS₄Preparation of precursor film

After the precursor solution is prepared, Ag is carried out₂PbSiS₄And (5) preparing a precursor film. To remove organic solvent residues from the precursor film, Thermogravimetric (TG) analysis (FIG. 1 b) of the precursor solution was first performed to identify Ag₂PbSiS₄And (3) pre-sintering temperature of the precursor film. Since the thermogravimetric analysis sample was obtained by heating for 1 h on a hot stage at 150 ℃ under a flowing atmosphere of argon, the weight loss of the sample before 150 ℃ was small. The loss of the sample between 150 ℃ and 250 ℃ is significant, while the change in the curve after 250 ℃ is small. The reason for the weight loss may be that the solvent is decomposed during heating to generate gas and volatilize and cause decomposition by a complex reaction with the metal. Accordingly, we convert Ag to₂PbSiS₄The presintering temperature of the precursor film is set to be 250 ℃, and the presintering time is set to be 2 min.

After the prefiring temperature was determined, the mixture was placed in a glove box where argon gas flowed (H)₂O＜1 ppm，O₂Less than 1 ppm) of Ag₂PbSiS₄Precursor solution at a rate of 3000 rmpThe film was spin coated on a calcium sodium glass sputtered with a 700nm Mo back contact layer for 30 s, and then placed on a pre-warmed fast heating stage and heated at 250 ℃ for 2 min. After 7 spin coating/presintering steps, Ag with a smooth surface and a thickness of 1.8 mu m is obtained₂PbSiS₄Precursor films (1c, d).

Then Ag is added₂PbSiS₄The precursor film is placed in a circular graphite box filled with 400 mg selenium particles, and then high-temperature annealing selenization is carried out in a rapid heating furnace (RTP) filled with flowing argon. After the selenization process is finished, cooling to room temperature in the flowing atmosphere of argon to obtain Ag₂PbSi(S,Se)₄Film of an absorption layer, FIG. 2(a) is Ag obtained₂PbSi(S,Se)₄XRD pattern of the absorption layer film; FIG. 2(b-d) is Ag₂PbSiS₄The precursor film is selenized Ag at 350 deg.C, 400 deg.C and 500 deg.C respectively₂PbSi(S,Se)₄Surface SEM image of thin film. As can be seen from the XRD pattern, the obtained absorption layer film is mostly Ag₂PbSi(S,Se)₄Phase (1); as can be seen from the SEM image, the surface of the absorption layer film is dense and uniform.

Experimental example 2

The preparation method of the silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material disclosed in this embodiment is the same as that in embodiment 1, except that in step 1), the volume dosages of the absolute ethyl alcohol, the 1-n-butylamine and the carbon disulfide are respectively 3ml, 2ml and 1.5ml, the stirring speed is 1000 rpm, and the stirring time is 20 min.

In the step 2), the metering ratio of the silver acetate, the lead oxide and the tetraethyl silicate is Ag: pb: si = 3: 1.5: 1.5, after each addition, the stirring temperature was 55 ℃, the stirring speed was 1100 rpm, and the magnetic stirring time was 2 h.

Experimental example 3

The preparation method of the silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material disclosed by the embodiment is the same as that in the embodiment 1, except that in the step 1), the volume dosages of absolute ethyl alcohol, 1-n-butylamine and carbon disulfide are respectively 5ml, 4ml and 3 ml;

in the step 2), the metering ratio of the silver acetate, the lead oxide and the tetraethyl silicate is Ag: pb: si = 5: 3: 3.

in other embodiments, step 4) may be performed by first using Ag₂PbSiS₄Placing the precursor film in a square stone cartridge containing 400-500 mg selenium particles, and annealing and selenizing at high temperature in an argon atmosphere; the high-temperature annealing selenization process is carried out under normal pressure, the selenization temperature is 350-550 ℃, the selenization time is 15-40 min, the heating rate is 7-10 DEG/s, the argon flow rate is 40-60 mL/min, and after selenization, the high-temperature annealing selenization process is carried out in the flowing atmosphere of argon to be cooled to the room temperature.

Comparative example 1

The preparation method of the silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material in the comparative example is the same as that in example 1, except that in the step 1), the volume dosages of the absolute ethyl alcohol and the 1-n-butylamine are respectively 2.5ml and 1 ml.

Comparative example 2

The preparation method of the silver-lead-silicon-sulfur-selenium film photovoltaic absorption layer material in the comparative example is the same as that in the example 1, except that in the step 1), the volume dosages of the absolute ethyl alcohol and the 1-n-butylamine are respectively 0.75ml and 1 ml.

Stability test

Ag prepared by the method of comparative example 1, comparative example 2 and examples 1, 2 and 3₂PbSiS₄The molecular precursor solutions are identified as comparative 1, comparative 2 and example 1, example 2 and example 3, respectively. Mixing the above Ag₂PbSiS₄The molecular precursor solution was left at room temperature for 12h (FIG. 3 a), 24h (FIG. 3 b), and 48h (FIG. 3 c). It was found that the system became unstable and cloudy at 6h (FIG. 3 e) in comparison 1 and 2, compared to the solution prepared at 0h (FIG. 3 d).

Film formation test

Ag was prepared using the methods described in comparative example 1, comparative example 2 and examples 1, 2 and 3₂PbSi(S,Se)₄Films were found to have poor film formation when prepared using comparative example 1 (fig. 4 a) and comparative example 2 (fig. 4 b). FIGS. 4c-4e show films prepared according to the methods described in examples 1, 2, and 3, respectively.