Antimony-based solar cell and method of making the same

Abstract

The application provides an antimony-based solar cell and a preparation method thereof, and belongs to the technical field of solar cells. The preparation method of the antimony-based solar cell comprises the following steps: after forming an electron transport layer on a conductive substrate and before forming an antimony-based light absorption layer on the electron transport layer, performing surface modification treatment on the electron transport layer, wherein the electron transport layer comprises a titanium dioxide film; the surface modification treatment comprises the following steps: coating a thiamine solution on the surface of the electron transport layer, wherein the thiamine solution comprises a solution formed by dissolving a sulfur source in an amine solvent; and performing annealing treatment on the electron transport layer coated with the thiamine solution in an air environment to obtain the surface-modified electron transport layer. Through the synergistic effect of the sulfur source and the amine molecules, the surface oxygen vacancy defect density of the titanium dioxide film is reduced, the antimony-based film with high crystallinity and low defect concentration can be prepared on the surface-modified electron transport layer, and the photoelectric performance of the antimony-based solar cell is improved.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and in particular to an antimony-based solar cell and its preparation method. Background Technology

[0002] Solar energy is a clean and renewable energy source, and antimony-based solar cells have broad application prospects due to their low cost, good stability, and non-toxicity. The light absorption efficiency of antimony-based thin films and the performance of devices based on antimony-based thin films largely depend on the quality of the antimony-based thin film, including nucleation uniformity, grain size, and continuity. During the fabrication of antimony-based thin films, the electron transport layer interface plays a crucial role in the nucleation behavior and grain growth of the antimony-based thin film, directly affecting the microstructure of the antimony-based thin film and the transport efficiency of photogenerated carriers, thus determining the overall performance of the device.

[0003] Titanium dioxide (TiO2), a commonly used electron transport layer, has a chemically inert surface and lacks active sites, making it difficult to effectively induce uniform nucleation and grain growth in antimony-based thin films. This results in uneven initial deposition of antimony-based films, which in turn limits the crystallinity of antimony-based films and device performance. Existing TiO2 interface treatment methods are generally complex to operate, making it difficult to achieve efficient control over the nucleation and grain growth of antimony-based films, thus limiting the improvement of antimony-based film quality and device performance. Summary of the Invention

[0004] In view of this, in order to at least partially solve the aforementioned technical problems, the present invention provides an antimony-based solar cell and a method for preparing the same.

[0005] According to one aspect of the present invention, a method for preparing an antimony-based solar cell is provided, comprising:

[0006] After forming an electron transport layer on a conductive substrate and before forming an antimony-based light-absorbing layer on the electron transport layer, the electron transport layer is surface-modified, wherein the electron transport layer includes a titanium dioxide thin film.

[0007] The surface modification process includes: coating the surface of the electron transport layer with a thiamine solution, wherein the thiamine solution comprises a solution formed by dissolving a sulfur source in an amine solvent; and annealing the electron transport layer coated with the thiamine solution in an air environment to obtain the surface-modified electron transport layer.

[0008] According to another aspect of the present invention, an antimony-based solar cell prepared by the above-described preparation method is provided.

[0009] According to the preparation method provided in the above embodiments of the present invention, SO4 is introduced onto the surface of the titanium dioxide thin film of the electron transport layer by surface modification. 2- -NH3 +The presence of active functional groups effectively passivates oxygen vacancy defects on the titanium dioxide surface, reduces the interface defect state density, and improves electron transport performance. Simultaneously, this surface modification alters the chemical activity and surface energy state of the electron transport layer, significantly increasing the initial nucleation density of the subsequent antimony-based light-absorbing layer. This promotes continuous nucleation and uniform growth of the antimony-based thin film, resulting in a dense, uniform, and pore-free high-quality antimony-based thin film. Based on these synergistic effects, interfacial carrier recombination is effectively suppressed, and carrier transport efficiency is improved, thereby significantly enhancing the open-circuit voltage, fill factor, and photoelectric conversion efficiency of antimony-based solar cells.

[0010] According to the preparation method provided in the above embodiments of the present invention, the preparation method is simple, has good repeatability, and is suitable for large-scale preparation of antimony-based solar cells by solution method. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0012] Figure 1 This is a cross-sectional schematic diagram of an antimony-based solar cell provided in an embodiment of the present invention;

[0013] Figure 2 Electron paramagnetic resonance (EPR) images of the surface-modified titanium dioxide film of Example 1, the surface-modified titanium dioxide film of Example 2, and the titanium dioxide film of Comparative Example 1.

[0014] Figure 3 The current-voltage (IV) test results are for the surface-modified titanium dioxide film of Example 1, the surface-modified titanium dioxide film of Example 2, and the titanium dioxide film of Comparative Example 1.

[0015] Figure 4 This is a scanning electron microscope image of the antimony selenide thin film deposited on the titanium dioxide thin film of Comparative Example 1 of the present invention.

[0016] Figure 5 This is a scanning electron microscope image of the antimony selenide sulfide film deposited on the surface-modified titanium dioxide film of Example 2 of the present invention;

[0017] Figure 6 The images show X-ray diffraction (XRD) patterns of the antimony selenide film deposited on the surface-modified titanium dioxide film of Example 2 of the present invention and the antimony selenide film deposited on the titanium dioxide film of Comparative Example 1.

[0018] Figures 7A-7BThe X-ray photoelectron spectroscopy (XPS) test results are shown for the surface-modified titanium dioxide film of Example 2 and the titanium dioxide film of Comparative Example 1.

[0019] Figure 8A This is a schematic diagram of the adsorption model of titanium dioxide thin film and antimony selenide sulfide thin film in Comparative Example 1 of the present invention.

[0020] Figure 8B This is a schematic diagram of the adsorption model of the surface-modified titanium dioxide film and the antimony selenide sulfide film in Example 2 of the present invention.

[0021] Explanation of reference numerals in the attached figures:

[0022] 1-Conductive substrate;

[0023] 2-Surface-modified electron transport layer;

[0024] 3-Antimony-based light-absorbing layer;

[0025] 4-Hole transport layer;

[0026] 5-Electrode. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. However, this invention can be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make the invention thorough and complete, and to fully convey the scope of the invention to those skilled in the art. In the accompanying drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated, and the same reference numerals denote the same elements throughout.

[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0029] In related technologies, the electron transport layer of antimony-based solar cells is typically TiO2, while the light absorption layer includes an antimony-based thin film. Antimony-based solar cells suffer from problems such as uneven nucleation and limited grain growth in the antimony-based thin film due to the chemical inertness of the TiO2 surface.

[0030] In view of this, the present invention provides an antimony-based solar cell and a method for preparing the same, wherein a high-quality antimony-based thin film is deposited on a titanium dioxide thin film of the antimony-based solar cell, thereby obtaining an antimony-based solar cell with better photoelectric conversion efficiency.

[0031] According to an exemplary embodiment of the present invention, the present invention provides a method for preparing an antimony-based solar cell, comprising: after forming an electron transport layer on a conductive substrate and before forming an antimony-based light absorption layer on the electron transport layer, performing a surface modification treatment on the electron transport layer, wherein the electron transport layer comprises a titanium dioxide thin film.

[0032] In embodiments of the present invention, the surface modification process includes operations S1 to S2.

[0033] Operation S1 involves coating the surface of the electron transport layer with a thiamine solution, wherein the thiamine solution comprises a solution formed by dissolving a sulfur source in an amine solvent.

[0034] In some embodiments, a sol-gel method is used to prepare titanium dioxide thin films. Specifically, a titanium source precursor, a complexing agent, and a solvent are mixed and stirred to form a titanium dioxide precursor sol. The precursor sol is then spin-coated onto the surface of a conductive substrate and subjected to high-temperature annealing to obtain a titanium dioxide thin film.

[0035] There are no restrictions on the precursor ratio, spin-coating parameters and annealing conditions involved in the preparation of titanium dioxide thin films; any scheme well known to those skilled in the art can be used.

[0036] In some embodiments, the sulfur source includes elemental sulfur.

[0037] In some embodiments, the amine solvent includes ethylenediamine, or a combination of ethylenediamine and 2-mercaptoethanol; more preferably, the amine solvent is ethylenediamine.

[0038] In some embodiments, the concentration of the sulfur source in the amine solvent is 1 × 10⁻⁶. -4 mol / L ~ 1×10 -2 mol / L, for example, 1×10 -4 mol / L, 1×10 -3 mol / L, 1×10 -2 mol / L, but not limited to the values ​​mentioned; a concentration more preferably 1×10 - 4 mol / L.

[0039] In some embodiments, coating the electron transport layer surface with a thiamine solution includes: spin-coating the thiamine solution onto the electron transport layer using a spin coating method, wherein the spin coating speed is 3000 rpm to 5000 rpm and the spin coating time is 10 s to 60 s; the speed is, for example, 3000 rpm, 3500 rpm, 4000 rpm, 4500 rpm, or 5000 rpm, and the spin coating time is, for example, 10 s, 20 s, 30 s, 50 s, or 60 s, but is not limited to the values ​​listed.

[0040] In step S2, the electron transport layer coated with thiamine solution is annealed in air to obtain a surface-modified electron transport layer.

[0041] In some embodiments, the annealing temperature for annealing the electron transport layer spin-coated with thiamine solution in an air environment is 300°C to 400°C, for example, 300°C, 320°C, 350°C, or 400°C, but not limited to the values ​​listed above; the heat treatment time is 1 min to 10 min, for example, 1 min, 2 min, 5 min, or 10 min, but not limited to the values ​​listed above; more preferably, the annealing temperature is about 350°C and the annealing time is 5 min.

[0042] In an embodiment of the present invention, the method for preparing an antimony-based solar cell further includes: forming an antimony-based light-absorbing layer on the surface-modified electron transport layer using a chemical method, such as chemical bath deposition or hydrothermal deposition.

[0043] Figure 1 This is a cross-sectional schematic diagram of an antimony-based solar cell provided in an embodiment of the present invention.

[0044] According to an exemplary embodiment of the present invention, the present invention provides an antimony-based solar cell, referenced to... Figure 1 As shown, the antimony-based solar cell includes a surface-modified electron transport layer 2 and an antimony-based light absorption layer 3.

[0045] In an embodiment of the present invention, the antimony-based solar cell further includes a conductive substrate 1, a surface-modified electron transport layer 2 located on the conductive substrate 1; a hole transport layer 4 located on the antimony-based light absorption layer 3; and an electrode 5 located on the hole transport layer 4.

[0046] In some embodiments, the antimony-based light-absorbing layer 3 includes at least one of antimony selenide, antimony sulfide, and antimony selenide sulfide.

[0047] In some embodiments, the conductive substrate 1 may be, for example, fluorine-doped tin dioxide transparent conductive glass (FTO), the surface-modified electron transport layer 2 may be surface-modified TiO2, the antimony-based light absorption layer 3 may be antimony selenide sulfide (Sb2(S,Se)3), the hole transport layer 4 may be Spiro-OMeTAD, and the electrode 5 may be a gold electrode.

[0048] In some embodiments, before forming an electron transport layer on FTO, FTO is ultrasonically cleaned sequentially with glass cleaner, ultrapure water, isopropanol, acetone, and anhydrous ethanol for 30 to 60 minutes each, and then dried with nitrogen.

[0049] In some embodiments, a titanium source precursor, a complexing agent, and an organic solvent are mixed and stirred to prepare a titanium dioxide precursor sol; the precursor sol is spin-coated onto a pretreated FTO surface with a thickness of about 40 nm to 60 nm, and then annealed in air at 450 °C for 30 min to obtain a dense titanium dioxide film.

[0050] In some embodiments, the method for preparing a gold electrode includes the following steps: depositing a gold electrode with a thickness of 60 nm to 80 nm using a thermal evaporation process. The parameters and conditions in the thermal evaporation process are not limited.

[0051] The following schematic illustration illustrates the design of an antimony-based solar cell and its fabrication method. It should be noted that this illustration is merely a specific embodiment of the present invention and does not limit the scope of protection of the present invention.

[0052] Example 1

[0053] (1) Preparation of titanium dioxide thin film:

[0054] 1.36 mL of titanium isopropoxide was mixed with 500 μL of diethanolamine and 4.2 mL of anhydrous ethanol and magnetically stirred for 1 h. Then, a mixed solution consisting of 2 mL of anhydrous ethanol and 72 μL of deionized water was added and stirring was continued to obtain a titanium dioxide precursor sol with a concentration of 0.552 mol / L.

[0055] Take 1 mL of the precursor sol and dilute it with 0.38 mL of anhydrous ethanol to obtain a titanium dioxide precursor solution with a concentration of 0.4 mol / L. Drop 50 μL of the precursor solution onto the surface of the pretreated FTO substrate and spin-coat it at 3000 rpm for 30 s. Then, heat it from room temperature to 450 °C in air for 20 min and anneal it at 450 °C for 30 min. Finally, allow it to cool naturally for 15 min to obtain a titanium dioxide film.

[0056] (2) Coating the surface of the titanium dioxide film with a thiamine solution:

[0057] Weigh 0.016 g of sulfur powder and add it to 50 mL of ethylenediamine. Stir magnetically at 60 °C for 2 h to obtain a concentration of 1 × 10⁻⁶ g / mL. -2 A mol / L thiamine solution was prepared; 50 μL of the thiamine solution was dropped onto the surface of the titanium dioxide film, and spin-coated at 4000 rpm for 30 s to ensure that the thiamine solution uniformly covered the surface of the titanium dioxide film.

[0058] (3) Annealing treatment of titanium dioxide film coated with thiamine solution:

[0059] The titanium dioxide film coated with thiamine solution was placed in an air atmosphere and annealed at 350°C for 5 minutes to obtain the surface-modified titanium dioxide film.

[0060] (4) Depositing antimony selenide sulfide film on the surface-modified titanium dioxide film:

[0061] 1 g of potassium antimony tartrate hemihydrate was added to 40 mL of ultrapure water and stirred until dissolved. Then, 1.1 g of sodium thiosulfate was added and stirred for 90 s. Next, 3 mL of sodium selenose sulfate (0.1 mol / L) was added, and stirring continued for 5 min to obtain a chemical bath deposition solution. The FTO / TiO2 substrate was placed in the chemical bath deposition solution and deposited in a 95°C water bath for 60 min. Subsequently, 0.1 g of thioacetamide was added, and deposition continued for another 60 min. After deposition, the substrate was rinsed with ultrapure water and dried with nitrogen. Then, it was annealed in a nitrogen glove box at 380°C for 10 min to obtain an Sb2(S,Se)3 absorber layer.

[0062] Example 2

[0063] A surface-modified titanium dioxide film is provided, differing from Example 1 in that the concentration of the thiamine solution in step (2) is changed from 1×10⁻⁶. -2 Replace mol / L with 1×10 -4 The concentration was mol / L, and other parameters and conditions were the same as in Example 1.

[0064] Comparative Example 1

[0065] (1) Preparation of titanium dioxide thin film:

[0066] 1.36 mL of titanium isopropoxide was mixed with 500 μL of diethanolamine and 4.2 mL of anhydrous ethanol and magnetically stirred for 1 h. Then, a mixed solution consisting of 2 mL of anhydrous ethanol and 72 μL of deionized water was added and stirring was continued to obtain a titanium dioxide precursor sol with a concentration of 0.552 mol / L.

[0067] Take 1 mL of the precursor sol and dilute it with 0.38 mL of anhydrous ethanol to obtain a titanium dioxide precursor solution with a concentration of 0.4 mol / L. Drop 50 μL of the precursor solution onto the surface of the pretreated FTO substrate and spin-coat it at 3000 rpm for 30 s. Then, heat it from room temperature to 450 °C in air for 20 min and anneal it at 450 °C for 30 min. Finally, allow it to cool naturally for 15 min to obtain a titanium dioxide film.

[0068] (2) Depositing antimony selenide thin film on titanium dioxide thin film:

[0069] 1 g of potassium antimony tartrate hemihydrate was added to 40 mL of ultrapure water and stirred until dissolved. Then, 1.1 g of sodium thiosulfate was added and stirred for 90 s. Next, 3 mL of sodium selenose sulfate (0.1 mol / L) was added, and stirring continued for 5 min to obtain a chemical bath deposition solution. The FTO / TiO2 substrate was placed in the chemical bath deposition solution and deposited in a 95°C water bath for 60 min. Subsequently, 0.1 g of thioacetamide was added, and deposition continued for another 60 min. After deposition, the substrate was rinsed with ultrapure water and dried with nitrogen. Then, it was annealed in a nitrogen glove box at 380°C for 10 min to obtain an Sb2(S,Se)3 absorber layer.

[0070] The surface-modified titanium dioxide film of Example 1, the surface-modified titanium dioxide film of Example 2, and the titanium dioxide film of Comparative Example 1 were characterized by electron paramagnetic resonance.

[0071] Figure 2 These are electron paramagnetic resonance (EPR) images of the surface-modified titanium dioxide film of Example 1, the surface-modified titanium dioxide film of Example 2, and the titanium dioxide film of Comparative Example 1.

[0072] refer to Figure 2 As shown, the EPR image of Comparative Example 1 shows a significant resonance signal at a Landé factor g=2.002, indicating the presence of numerous oxygen vacancy defects in the titanium dioxide film. Compared to Comparative Example 1, this signal is significantly weakened in the EPR image of Example 2, indicating that the oxygen vacancy defects in the titanium dioxide film are effectively suppressed after surface modification. The signal in the EPR image of Example 1 is further weakened, indicating that the oxygen vacancy defect density can be further reduced with the increase of the concentration of the treatment solution.

[0073] Electrodes were fabricated at both ends of the surface-modified titanium dioxide film of Example 1, the surface-modified titanium dioxide film of Example 2, and the titanium dioxide film of Comparative Example 1, and current-voltage tests were performed.

[0074] Figure 3 The current-voltage (IV) test results are for the surface-modified titanium dioxide film of Example 1, the surface-modified titanium dioxide film of Example 2, and the titanium dioxide film of Comparative Example 1.

[0075] refer to Figure 3 As shown, compared with Comparative Example 1, the conductivity of the surface-modified titanium dioxide film in Example 2 is significantly improved, indicating that the surface-modified titanium dioxide film has better electron transport capability; the conductivity of the surface-modified titanium dioxide film in Example 1 is slightly reduced, indicating that excessive surface modification is actually detrimental to conductivity.

[0076] The surface-modified titanium dioxide film of Example 2 and the antimony selenide sulfide film deposited on the titanium dioxide film of Comparative Example 1 were characterized by scanning electron microscopy (SEM).

[0077] Figure 4 This is a scanning electron microscope image of the antimony selenide sulfide film deposited on the titanium dioxide film of Comparative Example 1 of the present invention.

[0078] Figure 5 This is a scanning electron microscope image of the antimony selenide sulfide film deposited on the surface-modified titanium dioxide film of Example 2 of the present invention.

[0079] refer to Figure 4 , Figure 5 As shown, in Comparative Example 1, there were fewer nucleation sites in the early stage of antimony selenide sulfide film deposition, and obvious pores appeared on the surface after deposition, resulting in poor film continuity. In contrast, in Example 2, there were more nucleation sites in the early stage of antimony selenide sulfide film deposition, the surface was dense and continuous, and the grain distribution was more uniform. This indicates that the surface-modified titanium dioxide film is beneficial to the subsequent nucleation and grain growth of antimony selenide sulfide film.

[0080] The antimony selenide thin films prepared in Example 2 and Comparative Example 1 were characterized by X-ray diffraction.

[0081] Figure 6 The images show X-ray diffraction (XRD) patterns of the antimony selenide film deposited on the surface-modified titanium dioxide film of Example 2 of the present invention and the antimony selenide film deposited on the titanium dioxide film of Comparative Example 1.

[0082] refer to Figure 6 As shown, compared with Comparative Example 1, the diffraction peaks of the antimony selenide sulfide film in Example 2 are sharper, and the full width at half maximum (FWHM) is reduced, indicating that the crystallinity of the antimony selenide sulfide film is improved. This result demonstrates that surface modification of titanium dioxide can effectively control the early nucleation behavior of antimony selenide sulfide films, thereby promoting grain growth and improving film quality.

[0083] Figures 7A-7B The XPS test results are for the surface-modified titanium dioxide film of Example 2 and the titanium dioxide film of Comparative Example 1.

[0084] refer to Figure 7A As shown, the high-resolution S 2p spectrum of the surface-modified titanium dioxide film in Example 2 shows peaks at 169.5 eV and 168.4 eV, which can be attributed to sulfate (SO42-) ions. 2- This indicates that SO4 was introduced onto the surface of the surface-modified titanium dioxide film in Example 2. 2- Active groups.

[0085] refer to Figure 7BAs shown, the N 1s spectrum of the titanium dioxide film in Comparative Example 1 shows a peak at 400.0 eV, corresponding to the neutral amino group (-NH2) of residual diethanolamine in the precursor solution used to prepare the titanium dioxide film. The surface-modified titanium dioxide film in Example 2 exhibits an enhanced -NH2 signal and a new characteristic peak at 401.9 eV, corresponding to the protonated amino group (-NH3). + This indicates that -NH3 was introduced into the surface of the surface-modified titanium dioxide film of Example 2. + Active groups.

[0086] Figure 8A This is a schematic diagram of the adsorption model of the titanium dioxide thin film and the antimony selenide sulfide thin film in Comparative Example 1 of the present invention.

[0087] refer to Figure 8A As shown, based on first-principles calculations, the energy changes of the titanium dioxide thin film and antimony selenide sulfide thin film system in Comparative Example 1 can be obtained, and the adsorption energies E of S or Se adsorbed on the TiO2 surface in Comparative Example 1 can be derived. ads .

[0088] E of the titanium dioxide thin film and antimony selenide thin film system in Comparative Example 1 ads =E total -E surf -E S / Se E total E represents the energy of the TiO2 model that has adsorbed S or Se. surf E represents the energy of TiO2 when it exists alone. S / Se This represents the energy of S or Se.

[0089] The adsorption energy E of the antimony selenide sulfide film in Comparative Example 1 when S is adsorbed on the TiO2 surface can be obtained through calculation. ads The adsorption energy E of the antimony selenide sulfide film in Comparative Example 1 when Se is adsorbed on the TiO2 surface is 0.82 eV. ads It is 0.84 eV.

[0090] Figure 8B This is a schematic diagram of the adsorption model of the surface-modified titanium dioxide film and the antimony selenide sulfide film in Example 2 of the present invention.

[0091] refer to Figure 8B As shown, based on first-principles calculations, the energy changes of the surface-modified titanium dioxide film and antimony selenide sulfide film system in Example 2 can be obtained, and the adsorption energies E of S or Se adsorbed on the TiO2 surface by the antimony selenide sulfide film in Example 2 can be derived. ads .

[0092] E of the surface-modified titanium dioxide film and antimony selenide sulfide film system in Example 2 ads=E total -E surf -E NH3-S / Se E total This indicates that S and -NH3 have been adsorbed. + Or Se and -NH3 + The energy of the TiO2 model, E surf E represents the energy of TiO2 when it exists alone. NH3-S / Se Indicates S and -NH3 + Energy, or Se and -NH3 + Energy.

[0093] Calculations show that the adsorption energy E of the antimony selenide sulfide thin film in Example 2 when S is adsorbed on the TiO2 surface can be obtained. ads The adsorption energy E of the antimony selenide sulfide thin film in Example 2 when Se is adsorbed on the TiO2 surface is 2.35 eV. ads The adsorption energy is 1.89 eV, which is much greater than the adsorption energy of S and Se on the TiO2 surface of the antimony selenide sulfide film in Comparative Example 1. This indicates that -NH3 + It greatly promotes the adsorption of anions in Sb2(S,Se)3 by TiO2.

[0094] Application Example 1

[0095] This application example provides a method for preparing an antimony-based solar cell, including the following steps:

[0096] Titanium dioxide thin film deposition and surface modification: i.e., steps (1) to (3) of Example 1;

[0097] Antimony selenide thin film deposition: i.e. step (4) of Example 1;

[0098] (5) Hole transport layer (HTL) deposition:

[0099] In a glove box filled with N2, 36.6 mg of Spiro-OMeTAD was dissolved in 1 mL of chlorobenzene, followed by the addition of 14.5 μL of 4-tert-butylpyridine and 9.5 μL of Li-TFSI solution (520 mg / mL Li-TFSI in acetonitrile), and the mixture was thoroughly shaken. This solution was then spin-coated onto the surface of a Sb2(S,Se)3 film at 4000 rpm for 30 s, and annealed in air at 100 °C for 10 min to obtain an HTL layer.

[0100] (6) Gold electrode deposition:

[0101] A 65 nm thick Au electrode was deposited on an HTL using a thermal evaporation process. The evaporation process was carried out at a temperature of 5.0 × 10⁻⁶ nm. -4 The fabrication of the device was carried out under Pa pressure.

[0102] Application Example 2

[0103] The difference between Application Example 2 and Application Example 1 is that the concentration of the thiamine solution is changed from 1×10⁻⁶. -2 Replace mol / L with 1×10 -4 The concentration was mol / L, and other parameters and conditions were the same as in Application Example 1.

[0104] Comparative Application Example 1

[0105] The difference between Application Example 1 and Application Example 2 is that the surface modification treatment is omitted, and Sb2(S,Se)3 is deposited directly after the TiO2 film is deposited. Other parameters and conditions are the same as in Application Example 1.

[0106] Comparative Application Example 2

[0107] The difference between Application Example 2 and Application Example 2 is that the thiamine solution is replaced with 1×10 -4 The Na₂SO₄ aqueous solution was prepared in mol / L, with other parameters and conditions being the same as in Application Example 2.

[0108] Comparative Application Example 3

[0109] The difference between Application Example 3 and Application Example 2 is that the thiamine solution is replaced with an ethylenediamine solution, while the other parameters and conditions are the same as in Application Example 2.

[0110] Photoelectric performance testing

[0111] The solar cell devices prepared in Application Examples 1, 2, and Comparative Application Examples 1-3 were subjected to bright-state current-voltage (JV) curve testing at 25 °C. The light source was an XES-70S1 xenon lamp solar simulator, with irradiance calibrated to AM1.5 (1000 W / m²). 2 The voltage is provided by a Keithley 2400 digital source meter.

[0112] Table 1 Performance test results of different antimony-based solar cells

[0113]

[0114] According to the test results in Table 1, the photoelectric conversion efficiency (PCE) of the antimony-based solar cell in Comparative Application Example 1 is 8.02%; the PCE of the antimony-based solar cell in Application Example 2 is 8.86%, with the main improvements being in open-circuit voltage (Voc) and fill factor (FF). The PCE of the antimony-based solar cell in Application Example 2 is 9.33%, mainly due to significant improvements in Voc and FF, and a slight increase in short-circuit current density (Jsc). Compared to Comparative Application Example 1, the PCE of Application Example 1 is improved by approximately 16%.

[0115] Compared to Comparative Application Example 2 and Comparative Application Example 3, the antimony-based solar cell in Application Example 2 shows a significant improvement in photoelectric conversion efficiency, open-circuit voltage, fill factor, and short-circuit current density. This is because SO4 is simultaneously introduced onto the surface of titanium dioxide in Application Example 2. 2- -NH3 + The addition of active groups effectively passivates oxygen vacancy defects and enhances electron transport performance. Simultaneously, this surface modification significantly increases the nucleation density of the antimony-based light-absorbing layer, resulting in a denser, more uniform, and more crystalline film. These synergistic effects reduce interfacial carrier recombination and improve carrier transport and collection efficiency, thereby increasing open-circuit voltage and fill factor, ultimately significantly improving the photoelectric conversion efficiency of the solar cell.

[0116] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an antimony-based solar cell, characterized in that, include: After forming an electron transport layer on a conductive substrate and before forming an antimony-based light-absorbing layer on the electron transport layer, the electron transport layer undergoes surface modification treatment. The electron transport layer includes a titanium dioxide thin film; The surface modification process includes: A thiamine solution is coated on the surface of the electron transport layer, wherein the thiamine solution comprises a solution formed by dissolving a sulfur source in an amine solvent; The electron transport layer coated with thiamine solution was annealed in air to obtain a surface-modified electron transport layer. The sulfur source includes elemental sulfur; The amine solvent includes ethylenediamine, or a combination of ethylenediamine and 2-mercaptoethanol.

2. The preparation method according to claim 1, characterized in that, The concentration of the sulfur source in the amine solvent is 1×10 - 4 mol / L ~ 1×10 -2 mol / L.

3. The preparation method according to claim 1, characterized in that, Coating the surface of the electron transport layer with a thiamine solution includes: Thiamine solution was spin-coated onto the electron transport layer using a spin-coating method. The spin-coating speed was 3000 rpm to 5000 rpm, and the spin-coating time was 10 s to 60 s.

4. The preparation method according to claim 1, characterized in that, The annealing temperature is 300℃~400℃, and the annealing time is 1min~10min.

5. The preparation method according to claim 1, characterized in that, Also includes: The antimony-based light-absorbing layer is formed on the surface-modified electron transport layer using a chemical method.

6. The preparation method according to claim 5, characterized in that, The antimony-based light-absorbing layer includes at least one of antimony selenide, antimony sulfide, and antimony selenide sulfide.

7. The preparation method according to claim 5, characterized in that, Also includes: A hole transport layer is formed on the antimony-based light absorption layer; Electrodes are formed on the hole transport layer.

8. An antimony-based solar cell obtained by the preparation method according to any one of claims 1 to 7.

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