Multifunctional additive modified inverted perovskite solar cell

Abstract

The application discloses a multifunctional additive modified inverted perovskite solar cell. The structure of the cell is composed of a bottom electrode, a hole transport layer, a modification layer, a perovskite light absorption layer, an electron transport layer, a buffer layer and a counter electrode from top to bottom. The modification layer is made of one or two of PEAI, Cl-PEAI and F-PEAI. The perovskite light absorption layer is a perovskite containing 2-hydrazinobenzothiazole modification, and the doping amount of 2-hydrazinobenzothiazole in the perovskite active layer is 0.01-10wt%. The application effectively improves the photoelectric conversion efficiency of the perovskite solar cell, exhibits excellent photoelectric conversion performance, and has a wide and good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of novel photovoltaic solar cells, specifically relating to perovskite solar cells modified with multifunctional additives and their preparation methods. Background Technology

[0002] The arrival of the "energy crisis," exemplified by oil, has made humanity aware of the limitations, finiteness, and non-renewability of conventional energy sources. At the same time, environmental pollution and climate problems caused by the use of fossil fuels are becoming increasingly severe. Solar energy is inexhaustible, clean, pollution-free, and eliminates transportation issues, thus it holds the promise of becoming a major form of energy in the future. Metal halide perovskites possess unique advantages such as high photoelectric coefficient, high carrier mobility, and long charge diffusion length, making them ideal materials for solar cell fabrication. Perovskite solar cells fabricated from perovskites offer advantages such as simple fabrication processes, good optical performance, and the ability to be flexibly fabricated at low temperatures. Since the first cell was fabricated in 2009, the certified photoelectric conversion efficiency of perovskite solar cells has exceeded 25%, and commercialization is expected.

[0003] To date, the most significant challenge facing the commercialization of perovskite solar cells is their stability. Perovskite films fabricated using widely available solution processing methods inevitably introduce defects during the fabrication process. These defects cause nonradiative recombination losses, which are the primary reason for the loss of efficiency and stability in perovskite films. These defects can also act as charge recombination centers, leading to severe energy losses and reducing device efficiency. Simultaneously, these trapped states create conditions for moisture and oxygen to penetrate the perovskite layer, significantly degrading device stability. Therefore, much research has focused on regulating perovskite crystallization to reduce defects and improve film quality. Finding an effective method to reduce defects in perovskite films, thereby improving the efficiency and stability of perovskite solar cells, is of significant research importance. Additive engineering is considered one of the most effective strategies for reducing defect density.

[0004] The organic cations and PbI2 in perovskites are unstable during the rapid crystallization process of annealing, which leads to the formation of low-coordinated Pb at the grain boundaries and surface of perovskite films. 2+ These low-coordinated Pb 2+ In perovskite thin films, it acts as a non-radiative recombination center and significantly degrades the photovoltaic performance of perovskite devices. Furthermore, I0 in the perovskite precursor solution... -Pb is easily oxidized to I2, and the generated I2 is a major culprit in the formation of nonradiative recombination centers. Therefore, adding reducing agents to suppress I2 and reduce nonradiative recombination is crucial for improving device performance. Additive engineering is considered one of the most effective strategies for reducing defect density. For example, thiourea with S donors is incorporated into perovskite precursor solutions to regulate the defect distribution of perovskite polycrystalline films. Patent CN 108987583 A describes the doping of perovskite precursor solutions with thiazole additives containing S and N donors, which delays crystal growth by regulating the microenvironment of perovskite nucleation and crystallization, effectively suppressing bulk defects in perovskite. However, these studies only added passivating molecules containing lone pair electrons (S or N) that can act as Lewis bases, merely passivating the low-coordinate Pb. 2+ It did not take into account the influence of I2, and its role was relatively singular. Summary of the Invention

[0005] This invention addresses the limitations of current research on additives for passivating perovskite thin film defects, which offer limited types of defect passivation and limited passivation effects. It provides a multifunctional additive-modified inverted perovskite solar cell and its fabrication method. This method effectively utilizes the hydrazine functional group in 2-hydrazinobenzothiazole to oxidize I₂ in the perovskite precursor solution. - Reduction. Furthermore, the lone pair electrons in its molecular structure can interact with poorly coordinated Pb in the perovskite film. 2+ Addition to form Lewis adducts to passivate defects; the hydrophobic benzene ring can increase the hydrophobicity of the film, enhancing the moisture stability of the film and device. Therefore, adding 2-hydrazinobenzothiazole to the perovskite precursor solution can significantly improve the crystallinity of the perovskite film, passivate various defects, reduce the generation of nonradiative recombination centers in the film, suppress nonradiative recombination of charge carriers, and significantly improve the device's resistance to humidity, thereby improving the device's efficiency and stability. This invention effectively improves the photoelectric conversion efficiency of perovskite solar cells, exhibiting excellent photoelectric conversion performance and showing broad and promising application prospects.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A multifunctional additive-modified inverted perovskite solar cell, the cell device structure from bottom to top consists of a bottom electrode, a hole transport layer, a modification layer, a perovskite light absorption layer, an electron transport layer, a buffer layer and a counter electrode;

[0008] The perovskite light-absorbing layer is a perovskite modified with 2-hydrazinobenzothiazole, with a thickness of 300-700 nm. The perovskite light-absorbing layer is APbX3, where A=CH3NH. 3+ (MA +), CH(NH2) 2+ (FA + ), Cs + and Rb + One or more of the following; X=Cl - ,Br - and I - One or more of the following; the doping amount of 2-hydrazinobenzothiazole in the perovskite active layer is 0.01-10 wt%;

[0009] The hole transport layer is made of NiO. x PEDOT: Any one of PSS, PTAA, or CuSCN, with a thickness of 100~400nm;

[0010] The modified layer material is one or two of PEAI, Cl-PEAI, and F-PEAI, and the thickness is 10~30nm;

[0011] The electron transport layer includes PC 61 BM, or PC 61 BM and C 60 The combination of these has a thickness of 100~400 nm;

[0012] The buffer layer is either PEI or BCP, and its thickness is 10~50nm.

[0013] The bottom electrode is preferably one of ITO, FTO or IWO;

[0014] The counter electrode is preferably a Cu, Ag, Au, Cu / Ag composite electrode, or NiO. x / Ag / NiO x Any one of the composite electrodes, with a thickness of 60~120nm;

[0015] The method for preparing the inverted perovskite solar cell modified with the multifunctional additive includes the following steps:

[0016] Step (1), prepare hole transport layer

[0017] The hole transport layer component solution was spin-coated onto the bottom electrode and then annealed at 100-200℃ for 5-30 min to obtain the hole transport layer; wherein the concentration of the hole transport layer component solution was 20-40 mg / ml.

[0018] Step (2), Prepare the modification layer

[0019] The modification layer components were dissolved in isopropanol and spin-coated onto the hole transport layer to obtain the modification layer.

[0020] Step (3): Prepare a 2-hydrazinobenzothiazole-doped perovskite active layer.

[0021] The perovskite precursor was dissolved in a 2-hydrazinobenzothiazole precursor solution to obtain a 2-hydrazinobenzothiazole-doped perovskite precursor solution, which was then spin-coated onto the modification layer at a spin speed of 3000-5000 rpm for 3-12 s. After vacuum flash evaporation and annealing, a 2-hydrazinobenzothiazole-doped perovskite light-absorbing layer was obtained.

[0022] The 2-hydrazinobenzothiazole precursor solution is specifically prepared at a concentration of 0.02 mg / L. 100 mg of 2-hydrazinobenzothiazole was dissolved in 1 ml of a mixed solvent;

[0023] The perovskite precursors are of two types. The first type consists of 0.108–0.263 g FAI, 0.005–0.021 g CsI, 0.002–0.008 g RbI, 0.015–0.043 g MACl, 0.006–0.02 g PbCl2, 0.300–0.620 g PbI2, and 0.003–0.010 g PbBr2 per 1 mL of 2-hydrazinobenzothiazole precursor solution. The second type consists of 0.108–0.263 g CH(NH2)2I, 0.01–0.04 g CsI, 0.005–0.035 g CH3NH3Cl, 0.300–0.620 g PbI2, and 0.003–0.020 g PbBr2 per 1 mL of 2-hydrazinobenzothiazole precursor solution. CH3NH3Br;

[0024] In the 2-hydrazinobenzothiazole precursor solution, the mixed solvent composition is NMP and DMF, with a volume ratio of DMF:NMP = 5~6:1;

[0025] The vacuum flash evaporation process is as follows: the material is placed in a vacuum chamber, the vacuum pump is turned on, and the process is carried out at 5... Reduce the vacuum level to 5 within 15 seconds 15Pa, then remove under vacuum;

[0026] The annealing conditions are: annealing at 100℃~180℃ for 30~50s, followed by annealing at 80℃~135℃ for 30~80min;

[0027] Step (4) Fabrication of the electron transport layer

[0028] PC 61 BM or PC 61 BM and C 60 A chlorobenzene solution was spin-coated onto a perovskite thin film to form an electron transport layer;

[0029] Step (5) Prepare the buffer layer

[0030] A buffer layer is formed by uniformly spin-coating an isopropanol solution of PEI or BCP onto the electron transport layer.

[0031] Step (6) Preparation of the electrode;

[0032] Cu, Ag, Au, Cu / Ag composite electrodes, or NiO are deposited on the buffer layer using thermal evaporation. x / Ag / NiO x Any one of the composite electrodes.

[0033] The essential features of this invention are:

[0034] This invention involves adding a 2-hydrazinobenzothiazole additive containing multiple passivating groups during the preparation of the perovskite precursor solution. The hydrazine functional group in the 2-hydrazinobenzothiazole effectively oxidizes I₂ in the perovskite precursor solution. - Reduction. Furthermore, the lone pair electrons in its molecular structure can interact with poorly coordinated Pb in perovskite films. 2+ Addition to form Lewis adducts to passivate defects; the hydrophobic benzene ring can increase the hydrophobicity of the film, enhancing the moisture stability of the film and device. Therefore, doping an appropriate amount of 2-hydrazinobenzothiazole into the perovskite light-absorbing layer can significantly improve the crystallinity of the perovskite film, reduce the generation of nonradiative recombination centers in the film, suppress nonradiative recombination of charge carriers, and significantly improve the device's resistance to humidity, thereby improving the device's efficiency and stability.

[0035] The beneficial effects of this invention are as follows:

[0036] This invention improves the crystal quality of perovskite films by adding 2-hydrazinobenzothiazole as an additive during the preparation of the perovskite precursor solution. This effectively passivates defects, enhances the crystal quality of the perovskite film, reduces non-radiative recombination of charge carriers, and increases the humidity stability of the device, thus comprehensively improving the photoelectric conversion efficiency and stability of perovskite solar cells. Simultaneously, the presence of a benzene ring hydrophobic group in the additive significantly improves the humidity stability of the device. For example, a perovskite solar cell device doped with 2-hydrazinobenzothiazole maintains over 90% of its initial efficiency after 500 hours of exposure to 60% humidity air. In contrast, a perovskite solar cell device without 2-hydrazinobenzothiazole exhibits a sharp decline in photoelectric conversion efficiency to less than 1% after 500 hours of exposure to 60% humidity air. Compared to a standard sample without the additive, the device doped with 2-hydrazinobenzothiazole shows significant improvements in open-circuit voltage, short-circuit current, fill factor, and photoelectric conversion efficiency, which is a direct result of the multifunctional additive's simultaneous defect passivation. The perovskite solar cell device based on 2-hydrazinobenzothiazole doped retains 90% of its initial photoelectric conversion efficiency after 500 hours of exposure to air with 60% humidity, while the standard sample shows a significant decrease in efficiency after 500 hours, with efficiency remaining at less than 1%. This indicates that the humidity stability of the perovskite solar cell device based on 2-hydrazinobenzothiazole doped is significantly improved. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a perovskite solar cell structure;

[0038] Figure 1 shows the metal counter electrode 1, BCP buffer layer 2, electron transport layer 3, perovskite light absorption layer 4, PEAI modification layer 5, hole transport layer 6, and ITO conductive glass 7.

[0039] Figure 2 This is a scanning electron microscope image of the cross-section of the perovskite solar cell device prepared in Example 1;

[0040] Figure 3 This is a scanning electron microscope image of the 2-hydrazinobenzothiazole-doped perovskite light-absorbing layer thin film prepared in Example 1;

[0041] Figure 4 This is a scanning electron microscope image of the perovskite light-absorbing layer film prepared in Comparative Example 1 without the addition of 2-hydrazinobenzothiazole;

[0042] Figure 5 J is the perovskite solar cell device prepared in Example 1 and Comparative Example 1. V (current) Voltage test curve;

[0043] Figure 6These are the performance stability test curves of the perovskite solar cell devices prepared in Example 1 and Comparative Example 1;

[0044] Figure 7 These are XRD patterns of the perovskite films prepared in Example 1 and Comparative Example 1. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0046] like Figure 1 As shown, the perovskite solar cell consists of a counter electrode 1, a buffer layer 2, an electron transport layer 3, a perovskite light absorption layer 4, a modification layer 5, a hole transport layer 6, and a bottom electrode 7 from top to bottom.

[0047] The hole transport layer is made of NiO. x PEDOT: Any one of PSS, PTAA or CuSCN or any of their dopants, with a thickness of 100~400nm.

[0048] The modified layer is made of one of PEAI, Cl-PEAI or F-PEAI, and has a thickness of 10~30nm.

[0049] The perovskite light-absorbing layer is APbX3, where A = CH3NH. 3+ (MA + ), CH(NH2) 2+ (FA + ), Cs + and Rb + One or more of the following; X=Cl - ,Br - and I - One or more of them.

[0050] The light-absorbing layer is a perovskite light-absorbing layer modified with 2-hydrazinobenzothiazole, with a thickness of 300~700nm, wherein the doping amount of 2-hydrazinobenzothiazole in the perovskite precursor solution is 0.01-10wt%.

[0051] The electron transport layer includes PC 61 BM, or PC 61 BM and C 60 The combination of these has a thickness of 100~400 nm;

[0052] The buffer layer is either PEI or BCP, and its thickness is 10~50nm.

[0053] The bottom electrode is preferably one of ITO, FTO, or IWO, and the counter electrode is preferably Cu, Ag, Au, Cu / Ag composite electrode, or NiO. x / Ag / NiO x Any one of the composite electrodes, with a thickness of 60~120nm.

[0054] Example 1

[0055] Using ITO as the bottom electrode and NiO x For hole transport layer, PEAI is the decoration layer, and PC is the PC layer. 61 A perovskite solar cell device modified with 2-hydrazinobenzothiazole was fabricated using BM as the electron transport layer, BCP as the buffer layer, and copper as the counter electrode.

[0056] (1) Cleaning the transparent conductive glass substrate: Sonicate the ITO glass with glass cleaner, deionized water and ethanol for 15 minutes, then dry it with nitrogen, and finally treat it in ultraviolet-ozone for 30 minutes. The whole process is to clean the surface of the ITO glass.

[0057] (2) Preparation of the hole transport layer: 1 mol of Ni(NO3)2·6H2O was dispersed in 200 mL of deionized water to obtain a dark green solution. NaOH solution (10 mol / L) was then added. -1 The pH of the solution was adjusted to 10. After stirring for 25 minutes, the colloidal precipitate was washed five times with deionized water and dried at 90°C for 10 hours. The resulting green powder was then calcined at 270°C for 5 hours to obtain NiO. x Dark black powder. NiO with a mass percentage concentration of 2.9% was spin-coated onto an ozone-treated ITO substrate. x 70-10 μL of aqueous solution was spin-coated at 4000 rpm for 30 s, and then annealed at 100 °C for 10 min to obtain a hole transport layer with a thickness of 110 nm.

[0058] (3) Preparation of the modification layer: The NiO obtained in the previous step x On the top, spin-coat a PEAI modified layer solution (PEAI dissolved in IPA, 1 mg / ml) at a speed of 5000 rpm for 30 s to achieve a thickness of 30 nm.

[0059] (4) Preparation of perovskite light-absorbing layer: A perovskite layer was prepared on the PEAI obtained in the previous step by flash evaporation. First, an additive solution was prepared (0.5 mg of 2-hydrazinobenzothiazole dissolved in 1 ml of a mixture of NMP and DMF (DMF:NMP=5.45:1)). Weigh 0.248 g FAI, 0.01973 g CsI, 0.00658 g RbI, 0.035 g MACl, 0.01274 g PbCl2, 0.682 g PbI2 and 0.00853 g PbBr2 and dissolve them in 1 ml of the additive solution to prepare a perovskite precursor solution based on 2-hydrazinobenzothiazole doping;

[0060] Take 60 μL of the prepared precursor solution and spin-coat it onto the PEAI obtained in the previous step at a spin coating speed of 4000 rpm for 6 s. Then, place the sample in an evaporation hood for flash evaporation (vacuum degree of 10 Pa, holding pressure for 20 s), followed by annealing at 110 °C for 40 s and 135 °C for 35 min to prepare a perovskite active layer Rb with a thickness of 510 nm and a doping amount of 0.6 wt%. 0.02 (FA 0.95 Cs 0.05 ) 0.98 PbI 2.91 Br 0.03 Cl 0.06 Its appearance is like Figure 3 As shown;

[0061] (5) Fabrication of the electron transport layer: The pre-prepared PC 61 BM hole transport layer solution (per 23 mg PC) 61 BM dissolved in 1 ml of IPA was spin-coated onto the surface of the perovskite light-absorbing layer at a spin speed of 2500 rpm for 40 seconds and a thickness of 100 nm.

[0062] (6) Preparation of buffer layer: The pre-prepared BCP solution (5 mg BCP dissolved in 1 ml isopropanol) was spin-coated onto PC. 61 BM surface, spin coating speed controlled at 4000 rpm, spin coating time at 30 s, thickness at 10 nm;

[0063] (7) Preparation of counter electrode: 80 nm of Cu is deposited on the BCP obtained in the previous step.

[0064] Example 2

[0065] This embodiment provides a method for preparing a perovskite solar cell device modified with 2-hydrazinobenzothiazole. The implementation scheme is basically the same as that in Example 1, except that:

[0066] In step (4), the composition of the perovskite precursor is 0.155 g FA. I, 0.0259gCsI, 0.01g MACl, 0.507g PbI2 and 0.01g MABr.

[0067] Example 3

[0068] This embodiment provides a method for preparing a perovskite solar cell device modified with 2-hydrazinobenzothiazole. The implementation scheme is basically the same as that in Example 1, except that:

[0069] In step (4), the doping amount of 2-hydrazinobenzothiazole is 10 mg of 2-hydrazinobenzothiazole dissolved in 1 ml of a mixture of NMP and DMF.

[0070] Example 4

[0071] This embodiment provides a method for preparing a perovskite solar cell device modified with 2-hydrazinobenzothiazole. The implementation scheme is basically the same as that in Example 1, except that:

[0072] In step (4), the doping amount of 2-hydrazinobenzothiazole is 15 mg. 2-hydrazinobenzothiazole is dissolved in 1 ml of a mixture of NMP and DMF.

[0073] Example 5

[0074] This embodiment provides a method for preparing a perovskite solar cell device modified with 2-hydrazinobenzothiazole. The implementation scheme is basically the same as that in Example 1, except that:

[0075] In step (4), the doping amount of 2-hydrazinobenzothiazole is 110 mg. 2-hydrazinobenzothiazole is dissolved in 1 ml of a mixture of NMP and DMF.

[0076] Comparative Example 1

[0077] Using ITO as the bottom electrode and NiO x For hole transport layer, PEAI is the decoration layer, and PC is the PC layer. 61 A perovskite solar cell device without 2-hydrazinobenzothiazole modification was fabricated using BM as the electron transport layer, BCP as the buffer layer, and copper as the counter electrode (comparative device).

[0078] (1) Cleaning the transparent conductive glass substrate: Sonicate the ITO glass with glass cleaner, deionized water and ethanol for 15 minutes, then dry it with nitrogen, and finally treat it in ultraviolet-ozone for 30 minutes. The whole process is to clean the surface of the ITO glass.

[0079] (2) Preparation of the hole transport layer: 1 mol of Ni(NO3)2·6H2O was dispersed in 200 mL of deionized water to obtain a dark green solution. NaOH solution (10 mol / L) was then added. -1The pH of the solution was adjusted to 10. After stirring for 25 minutes, the colloidal precipitate was washed five times with deionized water and dried at 90°C for 10 hours. The resulting green powder was then calcined at 270°C for 5 hours to obtain NiO. x Dark black powder. NiO with a mass percentage concentration of 2.9% was spin-coated onto an ozone-treated ITO substrate. x 70-10 μL of aqueous solution was spin-coated at a speed of 4000 rpm for 30 s, and then annealed at 100 °C for 10 min to obtain a hole transport layer with a thickness of 110 nm.

[0080] (3) Preparation of the modification layer: The NiO obtained in the previous step x On the top, spin-coat a PEAI modified layer solution (PEAI dissolved in IPA, 1 mg / ml) at a speed of 5000 rpm for 30 s to achieve a thickness of 30 nm.

[0081] (4) Preparation of perovskite light-absorbing layer: A perovskite layer was prepared on the PEAI obtained in the previous step by flash evaporation. First, a perovskite precursor solution was prepared by weighing 0.248 g FAI, 0.01973 g CsI, 0.00658 g RbI, 0.035 g MACl, 0.01274 g PbCl2, 0.682 g PbI2 and 0.00853 g PbBr2 and dissolving them in 1 ml of mixed solvent (DMF:NMP=5.45:1).

[0082] Take 60 μL of the prepared precursor solution and spin-coat it onto the PEAI obtained in the previous step at a spin speed of 4000 rpm for 6 s. Then, place the sample in an evaporation hood for flash evaporation (vacuum degree of 10 Pa, pressure holding for 20 s), followed by annealing at 110 °C for 40 s and 135 °C for 35 min to prepare a perovskite active layer Rb with a thickness of 510 nm. 0.02 (FA 0.95 Cs 0.05 ) 0.98 PbI 2.91 Br 0.03 Cl 0.06 Its appearance is like Figure 4 As shown;

[0083] (5) Fabrication of the electron transport layer: The pre-prepared PC 61 BM hole transport layer solution (per 23 mg PC) 61 BM dissolved in 1 ml of IPA was spin-coated onto the surface of the perovskite light-absorbing layer at a spin speed of 2500 rpm for 40 seconds and a thickness of 100 nm.

[0084] (6) Preparation of buffer layer: The pre-prepared BCP solution (5 mg BCP dissolved in 1 ml isopropanol) was spin-coated onto PC.61 BM surface, spin coating speed controlled at 4000 rpm, spin coating time at 30 s, thickness at 10 nm;

[0085] (7) Preparation of counter electrode: 80 nm of Cu is deposited on the BCP obtained in the previous step.

[0086] Comparative Example 2

[0087] This comparative example provides a method for preparing a perovskite solar cell device modified with 2-mercaptobenzothiazole. The implementation scheme is basically the same as that in Example 1, except that:

[0088] The additive incorporated in step (4) is 2-mercaptobenzothiazole.

[0089] Comparative Example 3

[0090] This comparative example provides a method for preparing a thiazole-modified perovskite solar cell device. The implementation scheme is basically the same as that in Example 1, except that:

[0091] The additive incorporated in step (4) is thiazole.

[0092] In Example 1, the photoelectric performance of the prepared solar cell device was tested. The current density-voltage (J–V) characteristics were measured using a Keithley 2400 source measurement unit under simulated AM 1.5 irradiation (100 mW cm⁻¹). -2 Measurements were taken using a standard xenon lamp-based solar simulator (7ISO503A, SOFN INSTRUMENTS) with a scan voltage of 1.2~-0.2V and a scan step size of 0.05V. Figure 5 As shown in the figure (J of the perovskite solar cell device in Comparative Example 1): V test curve 501, J of perovskite solar cell device in Example 1 V test curve 502), through current Voltage curve characterization shows that for conventional devices without 2-hydrazinobenzothiazole, the open-circuit voltage is 0.96V and the short-circuit current is 24.99 mA / cm². 2 The fill factor is 74.87%, and the photoelectric conversion efficiency is 17.96%. The perovskite solar cell containing 2-hydrazinobenzothiazole has an open-circuit voltage of 1.03V and a short-circuit current of 25.46mA / cm². 2 The fill factor is 77.42%, and the photoelectric conversion efficiency is 20.40%. It can be observed that the photoelectric conversion efficiency of the perovskite solar cell device based on 2-hydrazinobenzothiazole doping is significantly better than that of the traditional solar cell device without 2-hydrazinobenzothiazole doping.

[0093] Figure 3and Figure 4 The images show SEM images of the perovskite films prepared in Comparative Example 1 and Example 1, respectively. It can be seen from the images that the grain size of the perovskite film modified with 2-hydrazinobenzothiazole is significantly larger than that of the perovskite film without 2-hydrazinobenzothiazole modification. This demonstrates that the 2-hydrazinobenzothiazole modification enhances the crystallinity of the film. This is evident from... Figure 7 The XRD patterns (XRD values ​​for Comparative Example 1 and Example 1 are 701 and 702 respectively) also demonstrate that the characteristic peak of the 110 crystal plane is higher in the perovskite film without 2-hydrazinobenzothiazole modification, indicating higher crystallinity and improved crystal quality. For the perovskite solar cell device based on 2-hydrazinobenzothiazole doping in Example 1, even after 500 hours of exposure to air with 60% humidity, its photoelectric conversion efficiency remains above 90% of the initial efficiency. However, the perovskite solar cell device without 2-hydrazinobenzothiazole doping shows a sharp decline in photoelectric conversion efficiency after 500 hours of exposure to air with 60% humidity. Figure 6 (In the figure: performance stability variation curve 601 of the perovskite solar cell device in Comparison 1, and performance stability variation curve 602 of the perovskite solar cell device in Example 1; where curves 601 and 602 are error curves obtained by combining 50 devices). This shows that doping with 2-hydrazinobenzothiazole can significantly improve the humidity stability of perovskite solar cell devices;

[0094] The photoelectric performance of the perovskite solar cells prepared in Examples 2, 3, 4, and 5, and Comparative Examples 2 and 3, was tested. The champion device in Example 2 achieved a photoelectric conversion efficiency of 20.38%, which is not significantly different from the 20.40% efficiency of the champion device in Example 1. This indicates that 2-hydrazinobenzothiazole can modify perovskite materials with different component ratios. The champion devices in Examples 3, 4, and 5 achieved efficiencies of 20.23%, 20.15%, and 18.12%, respectively. This demonstrates that the doping amount of the additive plays a positive role within the scope of the claims, while excessive addition outside the scope of the claims has little effect. To further demonstrate the outstanding effect of the multifunctional additive 2-hydrazinobenzothiazole, comparative experiments were conducted using thiazoles containing S and N atoms but without hydrazino groups and 2-mercaptobenzothiazole. The photoelectric conversion efficiencies of the champion devices in Comparative Examples 2 and 3 were 18.02% and 18.32%, respectively. This is because, compared to 2-hydrazinobenzothiazole, thiazole and 2-mercaptobenzothiazole have molecules in their structures that can passivate low-ligand Pb. 2+It contains S and N atoms, but lacks the reducing hydrazine group that can reduce I2, so its suppression effect on non-radiative recombination in the device is less than that of 2-hydrazinobenzothiazole.

[0095] The 2-hydrazinobenzothiazole-doped perovskite solar cells prepared in this invention show improvements in open-circuit voltage, short-circuit current, and fill factor compared to undoped standard devices. This results in a nearly three percentage point increase in the final device's power conversion efficiency, and a significant improvement in the device's humidity stability. This is because the hydrazine functional group in 2-hydrazinobenzothiazole can effectively oxidize I₂ in the perovskite precursor solution. - The reduction process allows the lone pair electrons in its molecular structure to interact with poorly coordinated Pb in the perovskite film. 2+ Additions form Lewis adducts to passivate defects. This passivation enhances the crystallinity of the perovskite film, reduces non-radiative recombination, and thus increases open-circuit voltage, short-circuit current, and fill factor, thereby improving power conversion efficiency. The hydrophobic benzene rings increase the film's hydrophobicity, which also contributes to the improved humidity stability of the device.

[0096] This invention is not limited to the embodiments described above and can be varied within the scope of the claims. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this invention is defined by the appended claims and their equivalents.

[0097] Matters not covered in this invention are common knowledge.

Claims

1. A multifunctional additive-modified inverted perovskite solar cell, characterized in that: The solar cell consists of a bottom electrode, a hole transport layer, a modification layer, a perovskite light absorption layer, an electron transport layer, a buffer layer, and a counter electrode, from top to bottom. The perovskite light-absorbing layer is a perovskite modified with 2-hydrazinobenzothiazole, with a thickness of 300~700nm; The perovskite light-absorbing layer is APbX3, where A=CH3NH. 3+ (MA + ), CH(NH2) 2+ (FA + ), Cs + and Rb + One or more of the following; X=Cl - ,Br - and I - One or more of the following; the doping amount of 2-hydrazinobenzothiazole in the perovskite active layer is 0.01-10 wt%.

2. The inverted perovskite solar cell modified with multifunctional additives as described in claim 1, characterized in that the hole transport layer is made of NiO. x PEDOT: Any one of PSS, PTAA, or CuSCN, with a thickness of 100~400nm; The modified layer material is one or two of PEAI, Cl-PEAI, and F-PEAI, and the thickness is 10~30nm; The electron transport layer includes PC 61 BM, or PC 61 BM and C 60 The combination of these has a thickness of 100~400 nm; The buffer layer is either PEI or BCP, and its thickness is 10~50nm. The bottom electrode is one of ITO, FTO or IWO; The counter electrode is a Cu, Ag, Au, Cu / Ag composite electrode, or NiO. x / Ag / NiO x Any one of the composite electrodes, with a thickness of 60~120nm.

3. The method for preparing the inverted perovskite solar cell modified with functional additives as described in claim 1, characterized in that: Includes the following steps: Step (1), prepare hole transport layer The hole transport layer component solution was spin-coated onto the bottom electrode and then annealed at 100~200℃ for 5~30min to obtain the hole transport layer. Step (2), Prepare the modification layer The modification layer components were dissolved in isopropanol and spin-coated onto the hole transport layer to obtain the modification layer. Step (3): Prepare a 2-hydrazinobenzothiazole-doped perovskite active layer. The perovskite precursor was dissolved in a 2-hydrazinobenzothiazole precursor solution to obtain a 2-hydrazinobenzothiazole-doped perovskite precursor solution, which was then spin-coated onto the modification layer at a spin speed of 3000-5000 rpm for 3-12 s. After vacuum flash evaporation and annealing, a 2-hydrazinobenzothiazole-doped perovskite light-absorbing layer was obtained. The 2-hydrazinobenzothiazole precursor solution is specifically prepared at a concentration of 0.02 mg / L. 100 mg of 2-hydrazinobenzothiazole was dissolved in 1 ml of a mixed solvent; In the 2-hydrazinobenzothiazole precursor solution, the mixed solvent composition is NMP and DMF, with a volume ratio of DMF:NMP = 5~6:1; The vacuum flash evaporation process is as follows: the material is placed in a vacuum chamber, the vacuum pump is turned on, and the process is carried out at 5... Reduce the vacuum level to 5 within 15 seconds 15Pa, then remove under vacuum; The annealing conditions are: annealing at 100℃~180℃ for 30~50s, followed by annealing at 80℃~135℃ for 30~80min; Step (4) Fabrication of the electron transport layer PC 61 BM or PC 61 BM and C 60 A chlorobenzene solution was spin-coated onto a perovskite thin film to form an electron transport layer; Step (5) Prepare the buffer layer A buffer layer is formed by uniformly spin-coating an isopropanol solution of PEI or BCP onto the electron transport layer. Step (6) Preparation of the counter electrode The counter electrode is deposited on the buffer layer using a thermal evaporation method.

4. The method for preparing the inverted perovskite solar cell modified with functional additives as described in claim 3, characterized in that the perovskite precursor has the following two compositions: the first composition is that each 1 mL of 2-hydrazinobenzothiazole precursor solution corresponds to 0.108~0.263 g FAI, 0.005~0.021 g CsI, 0.002~0.008 g RbI, 0.015~0.043 g MACl, 0.006~0.02 g PbCl2, 0.300~0.620 g PbI2 and 0.003~0.010 g PbBr2; Alternatively, the second option is that each 1 mL of 2-hydrazinobenzothiazole precursor solution corresponds to 0.108–0.263 g CH(NH2)2I, 0.01–0.04 g CsI, 0.005–0.035 g CH3NH3Cl, 0.300–0.620 g PbI2, and 0.003–0.020 g CH3NH3Br.

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