Light field manipulation doping method for tin-based perovskite solar cells

Abstract

The application provides a light field regulation and doping method for a tin-based perovskite solar cell, and belongs to the technical field of solar cells. 61 Methyl butyrate and indene-C 60 At least one of the double adducts. The tin-based perovskite solar cell treated by the method of the application can improve the open-circuit voltage and photoelectric conversion efficiency of the cell.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and more particularly to a method for photo-field modulation doping of tin-based perovskite solar cells. Background Technology

[0002] In recent years, perovskite semiconductor materials have attracted widespread attention due to their excellent photoelectric properties. The photoelectric conversion efficiency of lead-based perovskite solar cells has been continuously improving, showing broad industrialization prospects. However, the toxicity of the heavy metal lead limits the application scenarios of lead-based perovskite solar cells. Therefore, the next generation of low-toxicity and environmentally friendly tin-based perovskite solar cells has emerged.

[0003] However, the photoelectric conversion efficiency of tin-based perovskite solar cells is generally much lower than that of lead-based cells. One of the important factors is the large open-circuit voltage loss, which hinders the further improvement of their photoelectric conversion efficiency. Summary of the Invention

[0004] In view of this, in order to at least partially solve the problems mentioned above, the present invention provides a light field modulation doping method for tin-based perovskite solar cells to improve the open-circuit voltage of tin-based perovskite solar cells.

[0005] According to one aspect of the present invention, a method for photo-field modulation doping of a tin-based perovskite solar cell is provided, comprising: pre-treating the tin-based perovskite solar cell in a preset atmosphere, the preset atmosphere including water and oxygen; transferring the pre-treated tin-based perovskite solar cell to an inert gas environment; and irradiating the pre-treated tin-based perovskite solar cell under a solar simulator in the inert gas environment; wherein the tin-based perovskite solar cell includes a perovskite light-absorbing layer and an electron transport layer located on the perovskite light-absorbing layer, the perovskite light-absorbing layer including a tin-based perovskite thin film, and the electron transport layer including fullerene and [6,6]-phenyl C 61 Methyl butyrate and indene-C 60 At least one of the diadducts.

[0006] According to embodiments of the present invention, by performing a light-field-controlled doping process on tin-based perovskite solar cells, the water and oxygen adsorbed during the pretreatment stage can promote the movement of halogens in the perovskite crystal structure to the upper surface and into the electron transport layer under the influence of a light field. Simultaneously, the electron transfer between halide ions in the tin-based perovskite film and fullerenes and their derivatives in the electron transport layer will produce an n-type doping effect on this electron transport layer, increasing its Fermi level position and thus significantly improving the bandgap matching of the tin-based perovskite solar cell. By controlling the specific atmosphere and related processes of the illumination, the open-circuit voltage of the tin-based perovskite solar cell can be significantly improved, thereby obtaining tin-based perovskite solar cell devices with higher photoelectric conversion efficiency and stability. Attached Figure Description

[0007] 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. The drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0008] Figure 1 A flowchart illustrating the light field modulation doping method for tin-based perovskite solar cells provided in this embodiment of the invention;

[0009] Figure 2 A cross-sectional schematic diagram of a tin-based perovskite solar cell provided in an embodiment of the present invention;

[0010] Figure 3 Comparison chart showing the battery performance test results of tin-based perovskite solar cells provided in Comparative Examples 1-3 and Examples 1-3 of the present invention;

[0011] Figures 4A-4B The X-ray photoelectron spectroscopy and iodine (I) content comparison diagrams are shown for the interface between the tin-based perovskite thin film and the electron transport layer provided in Comparative Example 1 and Example 1 of the present invention, respectively.

[0012] Figure 5 A comparison diagram of the ultraviolet photoelectron spectra of the electron transport layer provided in Comparative Example 1 and Embodiment 1 of the present invention;

[0013] Figure 6 This is a comparison chart showing the battery performance test results of the tin-based perovskite solar cells provided in Comparative Example 2 and Examples 2, 4-5 of the present invention.

[0014] Explanation of reference numerals in the attached figures:

[0015] 1-Substrate;

[0016] 2- Bottom electrode;

[0017] 3-Hole transport layer;

[0018] 4-Perovskite light-absorbing layer;

[0019] 5-Electron transport layer;

[0020] 6-Cavity blocking layer;

[0021] 7-Top electrode. Detailed Implementation

[0022] 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.

[0023] 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.

[0024] The photoelectric conversion efficiency of tin-based perovskite solar cells is generally much lower than that of lead-based perovskite solar cells. One of the main reasons for this is the larger open-circuit voltage loss in tin-based perovskite solar cells. Because tin-based perovskite has a high valence band position in its band structure, the carrier transport layer inherited from lead-based perovskite solar cells has not yet achieved good band matching with the tin-based perovskite layer, leading to significant non-radiative recombination losses. This limits the open-circuit voltage of tin-based perovskite solar cells, thus hindering further improvements in their photoelectric conversion efficiency.

[0025] In view of this, the present invention provides a light field modulation doping method for tin-based perovskite solar cells to improve the open-circuit voltage of tin-based perovskite solar cells.

[0026] Figure 1 A flowchart illustrating the light field modulation doping method for tin-based perovskite solar cells provided in this embodiment of the invention.

[0027] According to an exemplary embodiment of the present invention, the present invention provides a method for optical field modulation doping of tin-based perovskite solar cells, referring to... Figure 1 As shown, it includes: operations S10 to S30.

[0028] In operation S10, the tin-based perovskite solar cell is placed in a preset atmosphere for pretreatment, which includes water and oxygen.

[0029] In embodiments of the present invention, the preset humidity range is 15% RH to 50% RH, for example, it can be 15% RH, 20% RH, 30% RH, 40% RH, or 50% RH, but is not limited to the values ​​listed above. If the humidity is too high, for example, exceeding 50% RH, the increase in the open-circuit voltage of the device is significant, but the yield of the device decreases as the humidity increases. If the humidity is too low, for example, less than 15% RH, the effect on improving the open-circuit voltage of the device is not significant. By controlling the humidity within the above-mentioned required range, a better device performance improvement effect and a higher yield can be achieved.

[0030] In embodiments of the present invention, the oxygen content ranges from 19.5% to 23.5%, for example, it can be 19.5%, 20%, 21%, 22%, 23%, or 23.5%, but is not limited to these values. Devices treated in environments with excessively high oxygen content show a significant increase in open-circuit voltage, but have low yield and are prone to large-scale damage. Devices treated in environments with excessively low oxygen content exhibit more stable performance, but the improvement in photoelectric conversion efficiency is not significant. By controlling the oxygen content within the aforementioned range, a better improvement in device performance and a higher yield can be achieved.

[0031] In embodiments of the present invention, the temperature range is 10 ℃ to 20 ℃, for example, 10 ℃, 12 ℃, 15 ℃, 18 ℃, 20 ℃, but not limited to the values ​​listed. If the temperature is too high (e.g., above 20 ℃), the performance of tin-based perovskite solar cells degrades severely, and the yield decreases; by controlling the temperature within the above-mentioned required range, a higher yield can be achieved.

[0032] In some embodiments, the preprocessing time can be 18 h to 24 h, for example, 18 h, 20 h, 21 h, 22 h, or 24 h, but is not limited to these values. If the preprocessing time is too long, the device will exhibit visible discoloration and degradation, and the device's test performance will be significantly reduced. If the preprocessing time is too short, the performance improvement will be significantly limited. By controlling the preprocessing time within the above-mentioned range, a better performance improvement can be achieved.

[0033] In some embodiments, the preset atmosphere is preferably 20% RH humidity, 21% oxygen content, 20 °C temperature, and the treatment time is 24 hours.

[0034] Operation S20 transfers the pretreated tin-based perovskite solar cell to an inert gas environment.

[0035] In some embodiments, the inert gas environment is characterized by a water content of less than 0.3 ppm, an oxygen content of less than 10 ppm, and a temperature range of 10 °C to 25 °C.

[0036] In embodiments of the present invention, the inert gas environment is preferably characterized by a water content of 0.01 ppm, an oxygen content of 0.1 ppm, and a temperature of 20 °C.

[0037] In operation S30, the pretreated tin-based perovskite solar cells are placed under a solar simulator for irradiation treatment in an inert gas environment.

[0038] In embodiments of the present invention, the light source of the solar simulator includes at least one of xenon lamps, carbon arc lamps, tungsten lamps, halogen lamps, and light-emitting diodes (LEDs).

[0039] In some embodiments, the irradiance of the solar simulator's light source is 400 W / m². 2 ~1500 W / m 2 For example, it can be 400 W / m 2 600 W / m 2 1000 W / m 2 1200 W / m 2 1500 W / m 2 However, this is not limited to the values ​​mentioned. Insufficient irradiance (e.g., less than 400 W / m²) 2 The irradiation intensity is too high, resulting in insufficient improvement in the open-circuit voltage of the device; excessive irradiation intensity will lead to a decrease in short-circuit current and a loss of fill factor. By controlling the irradiation intensity within the above-mentioned range, better open-circuit voltage, short-circuit current, and fill factor can be achieved.

[0040] In some embodiments, the irradiation duration is 20 min to 180 min, for example, 20 min, 50 min, 100 min, 150 min, or 180 min, but is not limited to the values ​​mentioned.

[0041] In embodiments of the present invention, the light source of the solar simulator is preferably a xenon lamp or an LED, and the irradiance of the light source is controlled to be 1000 W / m². 2 Process for 60 minutes.

[0042] Tin-based perovskite solar cells in related technologies widely employ fullerene electron transport layers inherited from lead-based perovskite solar cells. However, the conduction band of tin-based perovskites is much longer than that of conventional fullerene molecules (C0). 60The Fermi level of the electron transport layer leads to poor band mismatch, resulting in open-circuit voltage loss and reduced photoelectric conversion efficiency. This invention addresses this by performing light-field regulated doping on the fabricated tin-based perovskite solar cell. This induces ion movement at the interface between the perovskite light-absorbing layer and the electron transport layer, achieving high-quality fullerene doping. This improves the Fermi level position of the electron transport layer, mitigating the voltage loss caused by band mismatch and increasing the steady-state open-circuit voltage of the tin-based perovskite solar cell, thereby enhancing its photoelectric conversion efficiency.

[0043] In an embodiment of the present invention, the tin-based perovskite solar cell adsorbs water and oxygen during the pretreatment stage. The water and oxygen conditions cause vacancies to be generated in the tin-based perovskite film, forming more tin ions and halide ions in the interstitial positions of the lattice. This facilitates the movement of halide ions in the interstitial positions to the upper surface (the side closer to the electron transport layer) under the action of the light field and into the electron transport layer, thereby achieving n-type doping of the electron transport layer.

[0044] Figure 2 This is a cross-sectional schematic diagram of a tin-based perovskite solar cell provided in an embodiment of the present invention.

[0045] According to an exemplary embodiment of the present invention, the present invention provides a tin-based perovskite solar cell treated using the above-described optical field modulation doping method, with reference to... Figure 2 As shown, the tin-based perovskite solar cell is located on substrate 1. The tin-based perovskite solar cell includes, from bottom to top, a bottom electrode 2, a hole transport layer 3, a perovskite light absorption layer 4, an electron transport layer 5, a hole blocking layer 6, and a top electrode 7.

[0046] In some embodiments, the perovskite light-absorbing layer 4 comprises a tin-based perovskite film, wherein the general formula of the tin-based perovskite is ABX3, and the A-site comprises an organic ammonium ion or an alkali metal ion, such as CH3NH3. + (Methylamine, MA) + ), NH=CHNH3 + (methyl ether, FA + ) or Cs + B is Sn 2+ The X-position includes a halide ion, such as I. - ,Br - Cl - At least one of them. I - ,Br - Cl - The molar ratio can be, for example, 1:0:0, 0.98:0.02:0, 0.98:0.015:0.005, but is not limited to the values ​​mentioned.

[0047] In some embodiments, electron transport layer 5 includes fullerene (C 60 At least one of the following: fullerene and its derivatives. Preferably, the fullerene derivative includes [6,6]-phenyl-C 61 Methyl butyrate (PCBM) and indene-C 60 At least one of the diadducts (ICBA).

[0048] In some embodiments, the hole blocking layer 6 comprises a copper bath (BCP) layer with a thickness of 5 nm to 8 nm.

[0049] The following is an illustrative description of a light field modulation doping method designed for tin-based perovskite solar cells. 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 invention.

[0050] Comparative Example 1

[0051] The fabrication of tin-based perovskite solar cells specifically includes operations S1 to S6.

[0052] Operation S1: Substrate cleaning. Specifically, the indium tin oxide (ITO) transparent glass substrate is ultrasonically cleaned for 20 min each with glass cleaner, deionized water, acetone, and isopropanol, respectively. After drying in an oven, it is cleaned with a UV ozone generator for 15 min.

[0053] Operation S2: The hole transport layer is prepared as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT:PSS). Specifically, PEDOT:PSS is spin-coated onto an ITO transparent glass substrate at a speed of 5000 r / min in air with 10% RH humidity, and annealed at 150°C for 15 min. After the PEDOT:PSS film cools, the substrate coated with PEDOT:PSS is transferred into a glove box under a nitrogen atmosphere.

[0054] Step S3: Prepare a perovskite light-absorbing layer including a tin-based perovskite film. Specifically, prepare a 0.9 M FASnI3 tin-based perovskite precursor solution, with solutes being formamidinium hydroiodate (FAI), tin iodide (SnI2), and stannous fluoride (SnF2). The molar ratio of FAI, SnI2, and SnF2 is 1:1:0.1, and the solvent volume ratio is V. DMF :V DMSO A 4:1 mixture of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) was prepared. The resulting solution was spin-coated onto a hole transport layer at a spin speed of 5000 r / min for 40 s. At the 20th s of the spin-coating time, 600 μL of chlorobenzene (CB) was added dropwise. The mixture was then annealed at 80 °C for 10 min to obtain a FASnI3 perovskite film.

[0055] Operation S4: Fabrication of electron transport layer C 60 Specifically, a 20 nm thick C layer was formed using a thermal evaporation process. 60 .

[0056] Step S5: Fabrication of the hole-blocking layer (BCP). Specifically, an 8 nm thick BCP is formed using a thermal evaporation process.

[0057] Step S6: Prepare a silver or copper electrode. Specifically, a 100 nm thick silver or copper electrode is formed using a thermal evaporation process.

[0058] The photoelectric performance of the tin-based perovskite solar cell obtained in Comparative Example 1 was tested, and the test results are shown in Table 1.

[0059] Comparative Example 2

[0060] Tin-based perovskite solar cells were fabricated using the same method as in Comparative Example 1, except that a 0.9 M EDA solution was prepared. 0.01 FA 0.98 SnI 2.98 Br 0.02 Tin-based perovskite precursor solution.

[0061] Specifically, the tin-based perovskite precursor solution includes formamidinium hydroiodate (FAI), tin iodide (SnI2), stannous fluoride (SnF2), ethylenediamine dihydrobromide (EDABr2), and germanium diiodide (GeI2). The molar ratio of FAI, SnI2, SnF2, EDABr2, and GeI2 is 0.98:1:0.1:0.01:0.05, and the solvent volume ratio is V. DMF :V DMSO A 4:1 mixture of DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide) was prepared. The resulting solution was spin-coated onto a hole transport layer at a speed of 5000 rpm for 40 seconds. At the 15th second of spin-coating, 600 μL of CB (chlorobenzene) was added dropwise. The mixture was then annealed at 80 °C for 20 minutes to obtain EDA. 0.01 FA 0.98 SnI 2.98 Br 0.02 Perovskite thin films.

[0062] The photoelectric performance of the tin-based perovskite solar cell obtained in Comparative Example 2 was tested, and the test results are shown in Table 1.

[0063] Comparative Example 3

[0064] Tin-based perovskite solar cells were fabricated using the same method as in Comparative Example 1, except that 0.8 M PEA was prepared. 0.15 FA 0.85 SnI2.85 Br 0.15 Tin-based perovskite precursor solution, and preparation of the electron transport layer ICBA.

[0065] Specifically, prepare 0.8 M PEA 0.15 FA 0.85 SnI 2.85 Br 0.15 The tin-based perovskite precursor solution uses FAI, SnI2, SnF2, 2-(4-fluorophenyl)ethylamine hydrobromide (PEABr), and ammonium thiocyanate (NH4SCN), with a molar ratio of FAI, SnI2, SnF2, PEABr, and NH4SCN of 0.85:1:0.075:0.15:0.05 and a solvent volume ratio of V. DMF :V DMSO A 4:1 mixture of DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide) was prepared. The resulting solution was spin-coated onto a hole transport layer at a speed of 5000 r / min for 40 s. At the 26th s mark of spin-coating, 600 μL of Toluene was added dropwise. The mixture was then annealed at 70 °C for 10 min to obtain PEA. 0.15 FA 0.85 SnI 2.85 Br 0.15 Perovskite thin films.

[0066] The preparation of the ICBA electron transport layer includes: preparing a 20 mg / ml ICBA solution in CB (chlorobenzene); spin-coating the obtained solution onto the perovskite light-absorbing layer at a spin speed of 1000 r / min for 30 s; and annealing at 70 °C for 10 min to obtain the ICBA electron transport layer.

[0067] The photoelectric performance of the tin-based perovskite solar cell obtained in Comparative Example 3 was tested, and the test results are shown in Table 1.

[0068] Example 1

[0069] Tin-based perovskite solar cells were prepared using the same method as in Comparative Example 1. The difference was that, after preparation, the prepared tin-based perovskite solar cells were subjected to light field-controlled doping. The light field-controlled doping process included operations S7 to S9.

[0070] Operation S7: Pretreatment process. The tin-based titanium dioxide solar cells prepared above were placed in an atmosphere of 20 °C, 20% RH, and 21% oxygen content and left to stand for 24 h.

[0071] Operation S8: Transfer process. Transfer the pretreated tin-based titanium dioxide solar cells to a nitrogen glove box at 20 °C with a water content of 0.1 ppm and an oxygen content of 0.1 ppm for later use.

[0072] Operation S9: Light field processing. The transferred tin-based titanium dioxide solar cells are subjected to a light field treatment at 1000 W / m² under this atmosphere. 2 The device was exposed to AM 1.5G (the standard spectrum of the Earth's surface, defined as the reference spectrum for standard testing of solar energy conversion systems, with a standard AM 1.5G irradiance of 1000 W / m²) LEDs to simulate sunlight, ensuring that the light was incident perpendicularly onto the device surface from the transparent electrode surface for 120 minutes, and then left to stand in the dark for 5 minutes.

[0073] The photoelectric performance of the tin-based perovskite solar cell obtained in Example 1 was tested, and the test results are shown in Table 1.

[0074] Example 2

[0075] The prepared tin-based perovskite solar cells were treated using the same method as in Comparative Example 2. The difference was that, after preparation, the prepared tin-based perovskite solar cells were subjected to light field modulation doping. The light field modulation doping process included operations S7 to S9.

[0076] Operation S7: Pretreatment process. The tin-based titanium dioxide solar cells prepared above were placed in an atmosphere of 20 °C, 20% RH, and 21% oxygen content and left to stand for 24 h.

[0077] Operation S8: Transfer process. Transfer the pretreated tin-based titanium dioxide solar cells to a nitrogen glove box at 20 °C with a water content of 0.1 ppm and an oxygen content of 0.1 ppm for later use.

[0078] Operation S9: Light field processing. The transferred tin-based titanium dioxide solar cells are subjected to a light field treatment at 1000 W / m² under this atmosphere. 2 The AM 1.5G LED simulates sunlight, ensuring that the light is perpendicularly incident on the device surface from the transparent electrode surface for 60 minutes, and then the device is left to stand in the dark for 5 minutes.

[0079] The photoelectric performance of the tin-based perovskite solar cell obtained in Example 2 was tested, and the test results are shown in Table 1.

[0080] Example 3

[0081] The tin-based perovskite solar cells were processed using the same method as in Comparative Example 3. The difference was that, after the preparation was completed, the tin-based perovskite solar cells were subjected to light field modulation doping. The light field modulation doping process included operations S7 to S9.

[0082] Operation S7: Pretreatment process. The tin-based titanium dioxide solar cells prepared above were placed in an atmosphere of 20 °C, 20% RH, and 21% oxygen content and left to stand for 24 h.

[0083] Operation S8: Transfer process. Transfer the pretreated tin-based titanium dioxide solar cells to a nitrogen glove box at 20 °C with a water content of 0.1 ppm and an oxygen content of 0.1 ppm for later use.

[0084] Operation S9: Light field processing. The transferred tin-based titanium dioxide solar cells are subjected to a light field treatment at 1000 W / m² under this atmosphere. 2 The AM 1.5G LED simulates sunlight, ensuring that the light is incident perpendicularly onto the device surface from the transparent electrode surface for 20 minutes, and then the device is left to stand in the dark for 5 minutes.

[0085] The photoelectric performance of the tin-based perovskite solar cell obtained in Example 3 was tested, and the test results are shown in Table 1.

[0086] Example 4

[0087] Tin-based perovskite solar cells were prepared using the same method as in Example 2, and the prepared tin-based perovskite solar cells were treated with the same light field modulation doping method as in Example 2. The difference was that the humidity in the pretreatment process of the prepared tin-based perovskite solar cells was 40% RH and the oxygen content was 21%.

[0088] The photoelectric performance of the tin-based perovskite solar cell obtained in Example 4 was tested, and the test results are shown in Table 1.

[0089] Example 5

[0090] Tin-based perovskite solar cells were prepared using the same method as in Example 2, and the prepared tin-based perovskite solar cells were treated with the same light field modulation doping method as in Example 2. The difference was that the humidity in the pretreatment process of the prepared tin-based perovskite solar cells was 30% RH and the oxygen content was 21%.

[0091] The photoelectric performance of the tin-based perovskite solar cell obtained in Example 5 was tested, and the test results are shown in Table 1.

[0092] Example 6

[0093] Tin-based perovskite solar cells were prepared using the same method as in Example 2, and the prepared tin-based perovskite solar cells were treated with the same light field modulation doping method as in Example 2. The difference was that the humidity in the pretreatment process of the prepared tin-based perovskite solar cells was 10% RH and the oxygen content was 21%.

[0094] The photoelectric performance of the tin-based perovskite solar cell obtained in Example 6 was tested, and the test results are shown in Table 1.

[0095] Table 1

[0096]

[0097] Figure 3 This is a comparison chart showing the battery performance test results of Comparative Examples 1-3 and Examples 1-3 of the present invention. In this test, a Keithley 2400 digital source meter was used to scan the photocurrent density-voltage curves of the tin-based perovskite solar cells obtained in Comparative Examples 1-3 and Examples 1-3 of the present invention.

[0098] refer to Figure 3 As shown, the photoelectric conversion efficiency of the tin-based perovskite solar cells in the embodiments is significantly higher than that of the corresponding comparative tin-based perovskite solar cells. Specifically, the tin-based perovskite solar cell of Example 1 achieves a photoelectric conversion efficiency of 6.92% and a maximum open-circuit voltage of 0.48 V. In contrast, the tin-based perovskite solar cell of Comparative Example 1 has a photoelectric conversion efficiency of only 5.74% and an open-circuit voltage of only 0.4 V. The tin-based perovskite solar cell of Example 2 achieves a photoelectric conversion efficiency of 14.91% and a maximum open-circuit voltage of 0.8 V. In contrast, the tin-based perovskite solar cell of Comparative Example 2 has a photoelectric conversion efficiency of only 11.08% and an open-circuit voltage of only 0.59 V. The tin-based perovskite solar cell of Example 3 achieves a photoelectric conversion efficiency of 14.25% and a maximum open-circuit voltage of 0.89 V. In contrast, the tin-based perovskite solar cell of Comparative Example 3 has a photoelectric conversion efficiency of only 12.07% and an open-circuit voltage of only 0.81 V.

[0099] Figures 4A-4B The images show a comparison of X-ray photoelectron spectroscopy and I element content at the interface between the tin-based perovskite thin film and the electron transport layer provided in Comparative Example 1 and Example 1 of the present invention, respectively.

[0100] refer to Figure 4A , Figure 4B As shown, based on the comparison of the peak shape and peak area of ​​element I in the in-situ X-ray photoelectron spectroscopy reaction under synchrotron radiation, it can be determined that after optical field-controlled doping treatment, element I exhibits a new characteristic peak I0. 3-This characteristic peak indicates the occurrence of a redox reaction, suggesting electron transfer at the interface of the tin-based perovskite film after optical field-controlled doping. On the other hand, the increased peak area of ​​element I after optical field-controlled doping suggests that element I shifts towards the electron transport layer on the upper surface, increasing the element I content at the interface between the tin-based perovskite film and the electron transport layer, thus significantly enhancing the signal.

[0101] Figure 5 This is a comparison diagram of the ultraviolet photoelectron spectra of the electron transport layer provided in Comparative Example 1 and Embodiment 1 of the present invention.

[0102] like Figure 5 As shown, the ultraviolet photoelectron spectroscopy of Example 1 shows C 60 The surface binding energy shifted by 0.13 eV after optical field-controlled doping, indicating a 0.13 eV increase in the energy difference between the Fermi level and the valence band, directly demonstrating that C 60 The electron transport layer is further n-doped after processing, resulting in a bandgap fit effect. Figure 4A , Figure 4B The conclusions drawn, along with supporting research, demonstrate that halide ions such as iodine (I) can influence C-type ions through electron-donating reactions. 60 This invention utilizes the n-type doping mechanism of fullerene materials to induce light field modulation in tin-based perovskite solar cells. By incorporating appropriate amounts of water and oxygen adsorbed at the device surface during pretreatment, halogens in the perovskite crystal structure migrate upwards under the influence of a light field and enter the electron transport layer. Simultaneously, electron transfer between halide ions and fullerenes and their derivatives induces n-type doping in this electron transport layer, raising its Fermi level position and significantly improving the bandgap matching of the tin-based perovskite solar cell. Ultimately, by controlling the specific atmosphere and related processes of illumination, the open-circuit voltage of the tin-based perovskite solar cell is significantly increased, resulting in solar cell devices with higher photoelectric conversion efficiency and stability.

[0103] Figure 6 This is a comparison chart showing the battery performance test results of the tin-based perovskite solar cells provided in Comparative Example 2 and Examples 2, 4-5 of the present invention.

[0104] refer to Figure 6As shown in Table 1, the photoelectric conversion efficiency and open-circuit voltage of the tin-based perovskite solar cell in Example 1 are significantly higher than those of the tin-based perovskite solar cell in Comparative Example 1; the photoelectric conversion efficiency and open-circuit voltage of the tin-based perovskite solar cell in Example 2 are significantly higher than those of the tin-based perovskite solar cell in Comparative Example 2; and the photoelectric conversion efficiency and open-circuit voltage of the tin-based perovskite solar cell in Example 3 are significantly higher than those of the tin-based perovskite solar cell in Comparative Example 3.

[0105] Compared to Comparative Example 2, which did not undergo light field modulation doping treatment, Examples 2 and 4-6 all performed light field modulation doping treatment on the prepared tin-based perovskite solar cells, resulting in a significant improvement in the open-circuit voltage of the obtained tin-based perovskite solar cells. A comparison of Examples 2 and 4-6 reveals that the main difference lies in the water and oxygen environments used in the pretreatment process. Examples 2 and 5 exhibit superior cell performance compared to Examples 4 and 6. This is because the excessively high water and oxygen content in Example 4 oxidizes the tin-based perovskite solar cells, reducing their performance, while the excessively low water and oxygen content in Example 6 has no significant effect on improving cell performance. Therefore, it can be seen that a humidity range of 15% RH to 50% RH and an oxygen content range of 19.5% to 23.5% in the preset atmosphere of the pretreatment process are more preferred.

[0106] 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 light field manipulation doping method for a tin-based perovskite solar cell, the tin-based perovskite solar cell comprising a perovskite light absorption layer and an electron transport layer located on the perovskite light absorption layer, the perovskite light absorption layer comprising halide ions, characterized in that, The light field regulation doping method comprises: The tin-based perovskite solar cell is placed in a preset atmosphere for pretreatment, the preset atmosphere comprises water and oxygen, so that the tin-based perovskite solar cell absorbs water and oxygen, and the halogen ions are converted into free-moving halogen ions; And under the inert gas environment, the pretreated tin-based perovskite solar cell is placed under a solar simulator for irradiation treatment, so that the halogen ions in the perovskite light absorption layer are migrated to the electron transport layer, and halogen ion doping of the electron transport layer is realized; The perovskite light absorption layer is a tin-based perovskite thin film, the electron transport layer includes fullerene, [6,6]-phenyl C 61 methyl butyrate and indene-C 60 at least one of a bis-adduct; The humidity range of the preset atmosphere is 20 %rh~30 %rh, the oxygen content range is 19.5 %~23.5 %, and the temperature range is 10 ℃~20 ℃; The pretreatment time is 18 h~24 h.

2. The method of claim 1, wherein, The water content of the inert gas environment is less than 0.3 ppm, the oxygen content is less than 10 ppm, and the temperature range is 10 ℃~25 ℃.

3. The method of claim 1, wherein, The light source of the solar simulator comprises at least one of a xenon lamp, a carbon arc lamp, a tungsten lamp, a halogen lamp and a light-emitting diode.

4. The method of claim 1, wherein, The solar simulator has a light source irradiance of 400 W / m 2 1500 W / m 2 .

5. The method of claim 1, wherein, The light source of the solar simulator irradiates for 20 min~180 min.

6. The method of claim 1, wherein, The tin-based perovskite solar cell comprises, from bottom to top, a bottom electrode, a hole transport layer, the perovskite light absorption layer, the electron transport layer, a hole blocking layer and a top electrode.

7. The method of claim 1, wherein, The tin-based perovskite thin film has a general formula of ABX3, wherein X position includes at least one of I - , Br - , Cl - .

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