Perovskite solar cell doped with sulfonyl hydrazide foaming agent and preparation method thereof

Abstract

The invention discloses a perovskite solar cell doped with a sulfonyl hydrazide foaming agent and a preparation method thereof, and belongs to the field of photovoltaic power generation, a perovskite light absorption layer is FA1-x-yMAxCsyPb (I1-zBrz) 3 doped with the sulfonyl hydrazide foaming agent, x is equal to 0-1, y is equal to 0-1, and z is equal to 0-1. The sulfonyl hydrazine foaming agent interacts with uncoordinated Pb < 2 + > and I <->, and the sulfonyl hydrazine foaming agent is decomposed in the thermal annealing process to induce crystal grains to realize secondary fusion growth, so that defects in the perovskite light absorption layer are effectively passivated, recombination of photon-generated carriers of the perovskite solar cell is reduced, and the photoelectric conversion efficiency of the perovskite solar cell is improved. The open-circuit voltage, the fill factor and the photoelectric conversion efficiency of the perovskite solar cell are obviously improved, and the device efficiency PCE exceeds 26%; according to the preparation method provided by the invention, the p-i-n inversion structure device is prepared by spin coating through a one-step method, the preparation process is simple and convenient, and the cost is low.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic power generation, and particularly to a perovskite solar cell doped with a sulfonylhydrazide foaming agent and a preparation method thereof. Background Art

[0002] As a new type of optoelectronic material, perovskite thin films, represented by organic halide perovskites, exhibit revolutionary application prospects in the fields of photovoltaics, photodetection, and light-emitting devices due to their adjustable bandgap, high absorption coefficient, and long carrier diffusion length. Especially in perovskite solar cells, the quality of the perovskite thin film directly determines the performance and stability of the device.

[0003] The perovskite material is used as the light-absorbing layer in solar cells and usually exists in the form of a polycrystalline thin film prepared by a solution method. The quality of the light-absorbing layer is crucial for achieving efficient photoelectric conversion, and the quality of the light-absorbing layer depends to a large extent on the crystallization quality of the perovskite, including factors such as grain size, crystallization degree, and defect conditions inside the crystal. The generation of defects will become the center of carrier recombination, causing non-radiative transition recombination, reducing the charge separation and transport efficiency of perovskite solar cells, and even affecting the overall photoelectric conversion efficiency and stability. Therefore, studying how to effectively control the thin film growth process and improve the quality and stability of the thin film has become one of the urgent problems to be solved in the field of perovskite materials.

[0004] For example, the invention application with the publication number CN115988941A discloses a preparation method of a perovskite photovoltaic device based on a microporous structure, which successively prepares a substrate, a first electrode, a first carrier transport layer, a perovskite layer, a second carrier transport layer, and a second electrode. The first carrier transport layer is prepared on ITO glass; a mixed solution including a metal halide and a foaming agent is spin-coated on the first carrier transport layer, and a first annealing treatment is performed to prepare a porous solid metal halide thin film; an amine salt solution is spin-coated on the metal halide thin film, and a second annealing treatment is performed to realize the two-step preparation of the perovskite layer; the second carrier transport layer is prepared on the perovskite layer; and the second electrode is prepared on the second carrier transport layer. By introducing the foaming agent as an additive into the metal halide solution, a metal halide thin film with a microporous structure is prepared, which promotes the diffusion of the amine salt in the metal halide, increases the contact area between the two, makes the reaction between the two more sufficient, and obtains a high-quality perovskite thin film with large grain size and dense arrangement.

[0005] For another example, the invention application with the publication number CN116723744A discloses a method for preparing a high-performance tin-containing perovskite solar cell using a bifunctional hydrazide small molecule. By selecting bifunctional hydrazide small molecules such as p-toluenesulfonylhydrazide (PTSH) and oxalyl dihydrazide (ODZ) as additives for the tin-containing perovskite (ASnx Pb 1-x X3) The active layer of the solar cell is modified. Compared with the traditional Sn 2+ coordination strategy, in addition to being able to coordinate with Sn 2+ to provide an antioxidant environment for it, the bifunctional hydrazide small molecules selected in the present invention can also achieve the reduction of Sn 4+ to Sn 2+ This can greatly reduce the P-type self-doping effect and defect density caused by Sn 4+ in the perovskite film. Improve the photoelectric conversion efficiency and device stability of the prepared tin-containing perovskite solar cell.

[0006] Although adding additives such as polymers, fullerene derivatives, organic halide salts, metal halide salts, inorganic acids, etc. to the perovskite precursor solution has been proven to be able to prepare a uniform perovskite layer with high crystallinity and improve device performance, providing an effective way to improve the morphology and crystallinity of the film. However, most of these additives use existing functional groups or ions to interact with the perovskite. Due to their single passivation effect and slow diffusion speed, their spatial distribution inside the perovskite film usually cannot passivate newly generated defects during the crystallization process in real time, limiting the passivation effect of the additives and resulting in the inability to better improve the perovskite grain growth and crystallinity. Summary of the Invention

[0007] In order to solve the above technical problems, the present invention provides a perovskite solar cell doped with a sulfonyl hydrazide blowing agent and a preparation method thereof. By introducing a sulfonyl hydrazide blowing agent to regulate the entire thermal annealing crystallization process of the perovskite, the problems of small grains, many grain boundary defects, and uneven film quality existing in the perovskite film are greatly improved, and a highly efficient and stable inverted perovskite solar cell device is further successfully prepared.

[0008] A perovskite solar cell doped with a sulfonyl hydrazide blowing agent, the perovskite solar cell adopts an inverted structure, including a conductive base layer, a hole transport layer, a perovskite light absorption layer, an electron transport layer, an interface regulation layer, and a metal back electrode layer. The perovskite light absorption layer is FA doped with a sulfonyl hydrazide blowing agent 1-x-y MA x Cs y Pb(I 1-z Br z )3, where x = 0 to 1, y = 0 to 1, z = 0 to 1.

[0009] In the present invention, by adding a sulfonyl hydrazide blowing agent to FA 1-x-y MA x Cs y Pb(I 1-z Br z)3 system perovskite light absorption layer is doped with sulfonylhydrazide foaming agent, and the sulfone group, hydrazine group and other groups on the sulfonylhydrazide group can react with the uncoordinated Pb 2+ It interacts with I-plasma to passivate vacancy defects. During the thermal annealing process, the sulfonylhydrazine foaming agent gradually undergoes thermal decomposition to produce a passivating agent containing a S donor and a very small amount of water vapor. These trace products can diffuse along the grain boundaries and induce the grains to achieve secondary fusion growth, and effectively synergistically passivate the defects in the perovskite film. This positive passivation property greatly improves the crystallization quality of the perovskite, improves the film morphology, helps to improve the performance and stability of the perovskite light absorption layer, and further optimizes the performance of perovskite solar cells.

[0010] Take FA 1-x-y MA x Cs y Pb(I 1-z Br z )3 system as the perovskite light absorption layer, wherein the ABX3 type perovskite structure crystals have a high defect tolerance, and the use of a precursor solution containing ABX3 type perovskite structure crystals to prepare the perovskite light absorption layer helps to improve the stability of the perovskite solar cell device; and by adjusting the various components of ABX3, the band gap of the perovskite material can be changed, thereby improving the flexibility of the application of the perovskite solar cell device.

[0011] Preferably, FA 1-x-y MA x Cs y Pb(I 1-z Br z )3 is FA 0.85 MA0.1Cs 0.05 PbI3 or FA 0.84 MA 0.1 Cs 0.06 Pb(I 0.95 Br 0.05 )3.

[0012] Preferably, the sulfonylhydrazide foaming agent is benzenesulfonylhydrazide, p-toluenesulfonylhydrazide or 4,4-oxybisbenzenesulfonylhydrazide.

[0013] The above-mentioned sulfonylhydrazide foaming agents all contain sulfonyl and amino functional groups that can combine with uncoordinated lead ions or iodine vacancies to reduce surface and grain boundary defects and inhibit non-radiative recombination. During the annealing process, sulfonylhydrazide decomposes to produce gas, which can slow down the crystallization rate, promote the formation of large-grained, low-grain-boundary perovskite films, reduce recombination centers, and thus improve the open circuit voltage and fill factor.

[0014] More preferably, the sulfonylhydrazide foaming agent is benzenesulfonylhydrazide or p-toluenesulfonylhydrazide.

[0015] Preferably, the sulfonylhydrazine foaming agent and FA 1-x-y MA x Cs y Pb(I 1-z Br z )3 have a mass ratio of 0.05:1 to 55.

[0016] Selecting the sulfonylhydrazine foaming agent doped in the above range to prepare the perovskite precursor solution can effectively exert the positive passivation characteristics of the sulfonylhydrazine foaming agent on the perovskite light absorption layer before and after foaming, greatly extend the action range of the additive sulfonylhydrazine foaming agent in time and space, obtain a perovskite thin film with uniform spin coating and uniform quality, greatly improve the crystallization quality of the perovskite light absorption layer, and facilitate subsequent annealing treatment.

[0017] Preferably, the conductive base layer is ITO glass, the sheet resistance of ITO is 8 Ω, and the transmittance is 85%.

[0018] Indium tin oxide (ITO) has a large band gap. Selecting the ITO conductive substrate with the above specifications can provide high visible light transmittance and near-infrared reflectance, and has a very low resistivity, which can effectively improve conductivity.

[0019] Preferably, the hole transport layer is [4-(7H-dibenzo[c,g]carbazol-7-yl)butyl]phosphonic acid (4PADCB), and the thickness is 5 nm to 50 nm.

[0020] Single-molecule self-assembled phosphonate has high hole selectivity, high hole transport rate and low interface trap state density, and has a stable lattice structure. Selecting the hole transport layer with the above specifications can inhibit photoinduced halide segregation to enhance the stability of the device; and it also has molecular designability and excellent mechanical flexibility, which can be used to match the industrial production of perovskite solar cell devices.

[0021] Preferably, the electron transport layer is C60, and the thickness is 15 nm to 25 nm.

[0022] Selecting C60 as the electron transport layer has a wide band gap, a small refractive index and a high electron mobility, which can promote the effective separation of electrons and holes, reduce charge recombination and eliminate the hysteresis phenomenon.

[0023] Preferably, the interface control layer is BCP, and the thickness is 5 nm to 20 nm.

[0024] The interface control layer 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) can enhance carrier transport and prevent the dissociation of the surface structure of perovskite crystals, thereby improving the stability of the device.

[0025] Preferably, the metal back electrode layer is Ag with a thickness of 50 nm to 100 nm.

[0026] The back electrode metal Ag has good electrical conductivity and stability. Selecting Ag with the above thickness as the back electrode can solve the problem of back electrode contact in traditional devices and improve the efficiency and stability of the devices.

[0027] The present invention also provides a method for preparing a perovskite solar cell doped with a sulfonylhydrazide blowing agent, comprising the following steps:

[0028] (1) Pretreat the conductive substrate, spin-coat the hole transport layer and perform annealing treatment to obtain the hole transport layer;

[0029] (2) Add the sulfonylhydrazide blowing agent to the FA 1-x-y MA x Cs y Pb(I 1-z Br z )3 perovskite precursor solution and stir to obtain the FA1- x-y MA x Cs y Pb(I 1-z Br z )3 perovskite precursor solution containing the sulfonylhydrazide blowing agent;

[0030] (3) Spin-coat the FA 1-x-y MA x Cs y Pb(I 1-z Br z )3 perovskite precursor solution containing the sulfonylhydrazide blowing agent on the hole transport layer obtained in step (1). After the anti-solvent process and annealing treatment, a perovskite light absorption layer is obtained;

[0031] (4) Evaporate C 60 on the perovskite light absorption layer obtained in step (3) to obtain the C 60 electron transport layer; then evaporate BCP to obtain the BCP interface regulation layer; then evaporate Ag to obtain the perovskite solar cell doped with the sulfonylhydrazide blowing agent.

[0032] In the method for preparing a perovskite solar cell provided by the present invention, by introducing a sulfonylhydrazide blowing agent into the perovskite precursor solution, the foaming process of the blowing agent is synchronously coupled with the perovskite crystallization process, inducing the grains to achieve secondary fusion growth and effectively synergistically passivating the defects in the perovskite film.

[0033] Optionally, the pretreatment of the conductive substrate includes: first ultrasonically cleaning the conductive substrate, drying it with high-pressure inert gas, and then irradiating it with ultraviolet light to obtain the cleaned conductive substrate.

[0034] Preferably, the annealing temperature in step (1) is not less than 100° C., and the annealing time is not less than 10 min.

[0035] Preferably, the stirring time in step (2) is 15 min to 60 min.

[0036] Preferably, the spreading of the precursor solution in step (3) is performed by spin coating, blade coating or slit coating.

[0037] Choosing a suitable method of spreading the precursor solution can greatly shorten the coating speed, improve the utilization rate of the precursor solution, and obtain a film with high precision and uniform wet thickness.

[0038] More preferably, the precursor solution is spread by spin coating, the spin coating speed is 500 rpm to 5000 rpm, and the spin coating time is 20 s to 45 s.

[0039] Spin coating under the above spin coating process parameters can obtain a film with uniform distribution of perovskite components and appropriate thickness, which is convenient for subsequent anti-solvent process treatment.

[0040] Preferably, the anti-solvent process comprises: adding an anti-solvent dropwise for anti-dissolution 10s to 25s after the precursor solution begins to spread on the hole transport layer substrate, wherein the anti-solvent is anhydrous ether.

[0041] By using anhydrous ether, chlorobenzene or anisole as an anti-solvent for anti-dissolution, the crystallization process of the solute in the perovskite precursor solution is promoted during the solvent crystallization of the perovskite precursor solution.

[0042] Preferably, the annealing temperature in step (3) is 80-150° C., and the annealing time is 10 min-30 min.

[0043] Annealing treatment is carried out at the above-mentioned annealing temperature and annealing time, so that the sulfonylhydrazide foaming agent gradually undergoes thermal decomposition after reaching the foaming temperature (90-150°C), and the sulfonylhydrazide group gradually decomposes to produce a passivating agent containing an S donor and extremely small amounts of water vapor. These trace products can diffuse along the grain boundaries and induce the grains to achieve secondary fusion growth, and effectively and cooperatively passivate the defects in the perovskite film, so as to obtain a stable perovskite light absorption layer.

[0044] Optionally, the annealing atmosphere is a nitrogen atmosphere.

[0045] The beneficial effects of the present invention are:

[0046] (1) The present invention introduces a sulfonylhydrazide foaming agent and FA 1-x-y MA x Cs y Pb(I1-z Br z The uncoordinated Pb in 2+ and I - interact with each other, and the sulfonylhydrazine blowing agent decomposes during the thermal annealing process. The thermal decomposition products can induce the grains to achieve secondary fusion growth, effectively passivating the defects in the perovskite light absorption layer, reducing the recombination of photo-generated carriers in the perovskite solar cell, and significantly improving the open-circuit voltage, fill factor, and photoelectric conversion efficiency of the perovskite solar cell. Among them, the device efficiency PCE exceeds 26%.

[0047] (2) By doping the sulfonylhydrazine blowing agent in the perovskite precursor solution, the p-i-n inverted structure device prepared by one-step spin coating has a simple preparation process and low cost. Description of the Drawings

[0048] Figure 1 is the molecular formula of the sulfonylhydrazine blowing agent used in the present invention, where Figure 1 (a) in Figure 1 is benzenesulfonylhydrazide (BSH),

[0049] Figure 2 is the schematic diagram of the layered structure of the perovskite solar cell doped with the sulfonylhydrazine blowing agent in the embodiment of the present invention.

[0050] Figure 3 is the current-voltage curve graph of the perovskite solar cell device prepared in Comparative Example 1 without BSH doping and the perovskite solar cell device prepared in Example 1 with BSH doping;

[0051] Figure 4 is the current-voltage curve graph of the photoelectric conversion efficiency of the perovskite solar cell device prepared in Comparative Example 1 without TSH doping and the perovskite solar cell device prepared in Example 3 with TSH doping;

[0052] Figure 5 is the current-voltage curve graph of the photoelectric conversion efficiency of the perovskite solar cell device prepared in Comparative Example 2 without BSH doping and the perovskite solar cell device prepared in Example 4 with BSH doping;

[0053] Figure 6 is the box plot of the photoelectric conversion efficiency distribution of the perovskite solar cell device prepared in Comparative Example 1 without TSH doping and the perovskite solar cell devices prepared in Example 3 and Example 5 with TSH doping;

[0054] Figure 7 is the scanning electron microscope (SEM) image of the surface of the perovskite light absorption layer of the perovskite solar cell device prepared in Comparative Example 1 without BSH doping and the perovskite solar cell device prepared in Example 1 with BSH doping, Figure 7In (a) is Comparative Example 1, Figure 7 in (b) is Example 1;

[0055] Figure 8 are scanning electron microscope images of the surface of the perovskite light absorption layer prepared in Comparative Example 1 without BSH doping and the perovskite light absorption layer prepared in Example 2 with different concentrations of BSH doping;

[0056] Figure 9 are scanning electron microscope images of the cross-section of the perovskite light absorption layer prepared in Comparative Example 1 without BSH doping and the perovskite light absorption layer prepared in Example 1 with BSH doping, Figure 9 in (a) is Comparative Example 1, Figure 9 in Figure (b) is Example 1;

[0057] Figure 10 are scanning electron microscope images of the surface of the perovskite light absorption layer prepared in Comparative Example 3 without TSH doping and the perovskite light absorption layer prepared in Example 5 with TSH doping at different annealing temperatures, Figure 10 in (a) is Comparative Example 3, Figure 10 in (b) is Example 5;

[0058] Figure 11 are the photoluminescence spectrum (PL) and time-resolved photoluminescence spectrum (TRPL) of the perovskite light absorption layer prepared in Comparative Example 1 without BSH doping and the perovskite light absorption layer prepared in Example 1 with BSH doping, Figure 11 in (a) is the PL spectrum, Figure 11 in (b) is the TRPL spectrum;

[0059] Figure 12 are the atomic force microscopy (AFM) spectra of the perovskite light absorption layer prepared in Comparative Example 1 without BSH doping and the perovskite light absorption layer prepared in Example 1 with BSH doping, Figure 12 in (a) is the comparative example, Figure 12 in (b) is the example;

[0060] Figure 13 is the relationship diagram between the open circuit voltage (V OC ) of the perovskite solar cell device prepared in Comparative Example 1 without BSH doping and the perovskite solar cell device prepared in Example 1 with BSH doping and the light intensity. Detailed Description of the Invention

[0061] The following further describes the specific implementation of the present invention in detail with reference to the drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that for the processes not specifically described in detail below, those skilled in the art can implement or understand them with reference to the prior art.

[0062] Example 1

[0063] The perovskite solar cell device includes, from bottom to top, a conductive base layer, a hole transport layer, a perovskite light absorption layer, an electron transport layer, and a metal electrode.

[0064] The preparation steps of the perovskite solar cell device are as follows:

[0065] (1) Select ITO conductive glass with a sheet resistance of 8 Ω, a transmittance of 85%, and a size of 1.96 cm × 1.96 cm as the substrate. The ITO conductive substrate needs to be ultrasonically cleaned successively with deionized water, acetone, and isopropyl alcohol before use, dried with nitrogen, and then cleaned by ultraviolet light irradiation for 30 min.

[0066] (2) Preparation of the hole transport layer: Dissolve 0.8 mg of [4-(7H-dibenzo[c,g]carbazol-7-yl)butyl]phosphonic acid (4PADCB) in 2 mL of ethanol to prepare a hole transport layer solution. Then, drop 80 μL of the hole transport layer solution onto the ITO conductive substrate, spin-coat it at 3000 rpm for 30 s to deposit an ultrathin 4PADCB layer, and then anneal it at 100 °C for 10 min to obtain the hole transport layer.

[0067] (3) Preparation of the perovskite light absorption layer: Add benzenesulfonylhydrazide (BSH) with a concentration of 2 mg / mL to the 1.67 MFA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution and stir to obtain the FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution containing BSH;

[0068] Drop the prepared perovskite precursor solution onto the hole transport layer, spin-coat it at 4000 rpm for 30 s, and add 500 - 800 μL of anhydrous diethyl ether (DE) to the perovskite wet film 10 s after the start of spin-coating for anti-solution, and then anneal it at 100 °C for 30 min to obtain the perovskite light absorption layer;

[0069] (4) Preparation of the electron transport layer: Put the sample prepared in step (3) into a vacuum evaporation coating equipment. After the vacuum degree reaches 5×10 -4 Pa, deposit C at an evaporation rate of to obtain an electron transport layer with a thickness of 25 nm. 60

[0070] (5) Preparation of the interface control layer: Put the sample prepared in step (4) into a vacuum evaporation coating equipment. After the vacuum degree reaches 5×10 -4 Pa, deposit to obtain a BCP interface control layer with a thickness of 6 nm at an evaporation rate of ​

[0071] (6) Preparation of the metal electrode layer: The sample prepared in step (5) is placed in a vacuum evaporation coating equipment. After the vacuum degree reaches 5×10 -4 Pa, deposit metal Ag at an evaporation rate of to obtain an Ag metal electrode layer with a thickness of 100 nm.

[0072] Based on the above steps, a perovskite solar cell device is obtained, with an effective area of 0.04 cm 2 .

[0073] Example 2

[0074] The preparation steps of Example 2 are the same as those of Example 1, except that: Add benzenesulfonylhydrazide (BSH) with a concentration of 1 mg / mL to 1.67 M FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution and stir to obtain a FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution containing BSH.

[0075] Example 3

[0076] The preparation steps of Example 3 are the same as those of Example 1, except that: Add benzenesulfonylhydrazide (BSH) with a concentration of 4 mg / mL to 1.67 M FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution and stir to obtain a FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution containing BSH.

[0077] Example 4

[0078] The preparation steps of Example 4 are the same as those of Example 1, except that: Add benzenesulfonylhydrazide (BSH) with a concentration of 10 mg / mL to 1.67 M FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution and stir to obtain a FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution containing BSH.

[0079] Example 5

[0080] The preparation steps of Example 4 are the same as those of Example 1, except that benzenesulfonyl hydrazide (BSH) with a concentration of 20 mg / mL is added to 1.67 M FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution and stirred to obtain FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution.

[0081] Example 6

[0082] The preparation steps of Example 6 are the same as those of Example 1, except that benzenesulfonyl hydrazide (BSH) with a concentration of 40 mg / mL is added to 1.67 M FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution and stirred to obtain FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution.

[0083] Example 7

[0084] The preparation steps of Example 7 are the same as those of Example 1, except that p-toluenesulfonyl hydrazide (TSH) with a concentration of 2 mg / mL is added to 1.67 M FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution and stirred to obtain FA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution.

[0085] Example 8

[0086] The preparation steps of Example 8 are the same as those of Example 1, except that benzenesulfonyl hydrazide (BSH) with a concentration of 2 mg / mL is added to 1.62 M FA 0.84 MA 0.1 Cs 0.06 Pb(I 0.95 Br 0.05 )3 perovskite precursor solution and stirred to obtain FA 0.84 MA 0.1 Cs 0.06 Pb(I 0.95 Br 0.05 )3 perovskite precursor solution The perovskite light absorption layer is.

[0087] Example 9

[0088] The preparation steps of Example 9 are the same as those of Example 1, except that: in the preparation of the perovskite light absorption layer in step (3), annealing is carried out at 130 °C for 10 min to obtain the perovskite light absorption layer.

[0089] Comparative Example 1

[0090] Preparation process of perovskite precursor solution without doping BSH. The perovskite solar cell device includes a conductive base layer, a hole transport layer, a perovskite light absorption layer, an electron transport layer and a metal electrode from bottom to top.

[0091] The preparation steps of the perovskite solar cell device are as follows:

[0092] (1) Select ITO conductive glass with a sheet resistance of 8 Ω, a transmittance of 85%, and a size of 1.96 cm × 1.96 cm as the substrate. The ITO conductive substrate needs to be ultrasonically cleaned successively with deionized water, acetone and isopropanol before use, dried with nitrogen, and then cleaned by ultraviolet light irradiation for 30 min.

[0093] (2) Preparation of the hole transport layer: Dissolve 0.8 mg of [4-(7H-dibenzo[c,g]carbazol-7-yl)butyl]phosphonic acid (4PADCB) in 2 mL of ethanol to prepare the hole transport layer solution. Then, 80 μL of the hole transport layer solution is dropped onto the ITO conductive substrate, and a thin layer of 4PADCB is deposited by spin coating at 3000 rpm for 30 s, and then annealed at 100 °C for 10 min to prepare the hole transport layer.

[0094] (3) Preparation of the perovskite light absorption layer: Drop the prepared 1.67 MFA 0.85 MA 0.1 Cs 0.05 PbI3 perovskite precursor solution onto the hole transport layer, spin coat at 4000 rpm for 30 s, and add 500 - 800 μL of anhydrous ether (DE) to the perovskite wet film for anti-solution 10 s after the start of spin coating, and then anneal at 100 °C for 30 min to obtain the perovskite light absorption layer;

[0095] (4) Preparation of the electron transport layer: The sample prepared in step (3) is placed in a vacuum evaporation coating equipment. After the vacuum degree reaches 5×10 -4 Pa, deposit C at an evaporation rate of to obtain an electron transport layer with a thickness of 25 nm. 60

[0096] (5) Preparation of the interface control layer: The sample prepared in step (4) is placed in a vacuum evaporation coating equipment. After the vacuum degree reaches 5×10 -4 Pa, deposit to obtain a BCP interface control layer with a thickness of 6 nm at an evaporation rate of ​

[0097] (6) Preparation of the metal electrode layer: The sample prepared in step (5) is placed in a vacuum evaporation coating equipment. After the vacuum degree reaches 5×10 -4 Pa, deposit metal Ag at an evaporation rate of to obtain an Ag metal electrode layer with a thickness of 100 nm.

[0098] Based on the above steps, a perovskite solar cell device is obtained, with an effective area of 0.04 cm 2 .

[0099] Comparative Example 2

[0100] The preparation steps of Comparative Example 2 are the same as those of Comparative Example 1, except that: the prepared 1.62 M Cs 0.05 (FA 0.96 MA 0.04 ) 0.95 (I 0.95 Br 0.05 )3 perovskite precursor solution is dropped onto the hole transport layer.

[0101] Comparative Example 3

[0102] The preparation steps of Comparative Example 3 are the same as those of Comparative Example 1, except that: in the preparation of the perovskite light absorption layer, anneal at 130 °C for 10 min to obtain the perovskite light absorption layer.

[0103] Detection Example 1

[0104] Analyze the optoelectronic properties of the perovskite solar cells (PSCs) prepared in Examples 1, 3, 4, 5 and Comparative Examples 1, 2, 3.

[0105] Under the simulated sunlight irradiation condition of AM1.5 (light intensity is 100 mW / cm 2 ), test the current-voltage curves (J-V) of the PSCs prepared in Examples 1, 3, 4, 5 and Comparative Examples 1, 2, 3 respectively, with a reverse scan from 1.5 V to 0.5 V and a scan rate of 20 mV / s, (device effective area: 0.04 cm 2 ), and the results are shown in Tables 1, 2, 3 and Figure 3 , 4 , 5, 6. Among them, Table 1 shows the optoelectronic performance parameters of PSCs prepared by doping BSH into FA 0.85 MA 0.1 Cs 0.05 PbI3 and annealing at 100 °C, Table 2 shows the optoelectronic performance parameters of PSCs prepared by doping TSH into FA 0.85 MA 0.1 Cs 0.05 PbI3 and annealing at 100 °C, and Table 3 shows the optoelectronic performance parameters of PSCs prepared by doping BSH into Cs0.05 (FA 0.96 MA 0.04 ) 0.95 (I 0.95 Br 0.05 )3 and anneal at 100 °C to prepare the optoelectronic performance parameters of PSCs.

[0106] Table 1

[0107]

[0108] Table 2

[0109]

[0110] Table 3

[0111]

[0112] From Tables 1, 2 and Figure 3 and 4 it can be seen that after doping with BSH and TSH, the open-circuit voltage (V OC ) and fill factor (FF) of the perovskite solar cells have both been improved. Among them, the optoelectronic efficiency (25.62%) of the device doped with BSH in Example 1 (effective area: 0.04 cm 2 ) is higher than that of the device without BSH doping in Comparative Example 1 (23.18%). The optoelectronic efficiency (24.80%) of the device doped with TSH in Example 3 (effective area: 0.04 cm 2 ) is higher than that of the device without TSH doping in Comparative Example 1 (23.90%). It is proved that after doping treatment with BSH and TSH, both play a role in improving the optoelectronic performance of the perovskite cells. The treatment effect of TSH is weaker than that of BSH because in Examples 1 and 3, the annealing temperature of the perovskite film is only 100 °C. At this temperature, only BSH can foam to produce S-containing donor passivators and trace amounts of water vapor. These foaming products can further regulate the defects and grain growth in the film, thereby improving the film quality. While TSH fails to start foaming at 100 °C and only plays a passivation role by its own sulfonylhydrazide group. Although it can also improve the device performance, the improvement effect is not as good as that of the foamed BSH.

[0113] From Table 3 and Figure 5 it can be seen that for the perovskite solar cell device of the Cs 0.05 (FA 0.96 MA 0.04 ) 0.95 (I 0.95 Br 0.05 )3 system doped with BSH in Example 4 (effective area: 0.04 cm 2) The photoelectric efficiency (26.02%) is higher than that of the battery device without BSH doping in Comparative Example 2 (23.90%), which once again proves that the BSH doping treatment plays a role in improving the optoelectronic performance of perovskite solar cells, and also reflects the universal effect of BSH treatment on different perovskite systems.

[0114] It can be seen from Figure 6 that after the TSH regulation in Example 3, the device efficiency of the perovskite solar cell is improved. For the perovskite solar cell in Example 5, annealing is carried out at 130 °C, and 130 °C is within the foaming temperature range of TSH. After the TSH doping treatment in Example 5, the average device efficiency (24.25%) is greatly improved compared with that in Comparative Example 1 (22.75%), and it is also higher than the efficiency of the TSH-doped device (23.84%) annealed at 100 °C in Example 3. The results show that TSH has a good improvement effect on the device performance after foaming during the perovskite thermal annealing process, because new S-containing donor passivators and trace amounts of water vapor are also generated during the TSH foaming process. Under the combined action of the new passivators and trace amounts of water, the defects generated during the annealing process in the perovskite film are passivated in real time, greatly improving the film quality.

[0115] Test Example 2

[0116] The scanning electron microscope (SEM) was used to characterize the microtopography of the perovskite light absorption layer films prepared in the examples and comparative examples.

[0117] It can be seen from Figure 7 (a) and Figure 7 (b) that by comparison, the grain size of the perovskite film in Comparative Example 1 is smaller, and there are obvious holes between the grains. After BSH doping, the perovskite film has larger grains, and the holes on the grain boundaries basically disappear. This is the result of the regulation of grain growth by BSH and its foaming products, greatly improving the film quality and device performance.

[0118] It can be seen from Figure 8 that as the BSH doping concentration increases, the grain size continuously increases. When the concentration exceeds 10 mg / ml, white particles begin to appear on the grain surface. This is because the sulfonylhydrazine blowing agent gradually undergoes thermal decomposition to produce trace amounts of water vapor. These trace products can diffuse along the grain boundaries and induce the grains to achieve secondary fusion growth. However, if the concentration exceeds 40 mg / ml, obvious holes appear between the grain boundaries, but the film quality deteriorates, and the amount of water vapor generated by BSH foaming is too much, leading to the degradation of perovskite.

[0119] It can be observed from Figure 9 that for the sample doped with BSH prepared in Example 1, the grains are significantly larger in cross-section, and at the same time, more grains show a vertical orientation, indicating that BSH doping can effectively regulate the crystallization orientation and improve the film morphology.

[0120] Figure 10 Scanning electron microscope images of the surface of the perovskite light absorption layer prepared in Comparative Example 3 without TSH doping and the perovskite light absorption layer prepared in Example 5 with TSH doping and annealed at 130 °C. It can be seen that white particles appear between the grains after annealing at 130 °C. It may be that lead iodide is produced due to the degradation of perovskite under such long-term high-temperature annealing. Obvious stepped rough patterns appear on the grain surface. After being regulated by TSH, the grain size increases significantly, which once again proves that the foamed TSH also has an improvement effect on the growth of perovskite crystals.

[0121] Detection Example 3

[0122] The photoluminescence spectra (PL) of the perovskite light absorption layer films prepared in Example 1 and Comparative Example 1 were analyzed to characterize the defect density. From Figure 11 (a), it can be seen that the emission intensity of the perovskite light absorption layer film after BSH doping treatment is much higher than that of the perovskite light absorption layer film without BSH doping treatment. This can be attributed to the fact that the modification effect of the additive improves the film-forming quality of the perovskite film, making the film grain size larger and suppressing non-radiative transitions. From Figure 11 (b), it can be seen that the average lifetime of the perovskite film without BSH doping is 230 ns, while the lifetime of the perovskite film doped with BSH increases to 1150 ns. It shows that BSH can effectively passivate the defects in the film and improve the quality of the perovskite film.

[0123] Detection Example 4

[0124] The atomic force microscope (AFM) was used to test the perovskite light absorption layer films prepared in Example 1 and Comparative Example 1 to obtain the surface roughness (Ra) of the perovskite film, as Figure 12 shown.

[0125] From Figure 12 the results, it can be seen that the Ra of Comparative Example 1 is 18.5 nm, while the surface roughness of Example 1 decreases significantly, and its Ra is 12.7 nm. The test results of AFM show that the perovskite film doped with BSH is smoother and flatter. Doping BSH in the perovskite light absorption layer can effectively reduce the roughness of the perovskite film.

[0126] Detection Example 5

[0127] The performance of the perovskite solar cell devices prepared in the examples and comparative examples was characterized.

[0128] Figure 13 For the relationship diagram of V of the perovskite solar cell prepared in Comparative Example 1 without BSH doping and the perovskite solar cell doped with BSH prepared in Example 1; From OC the figure; FromFigure 13 It can be seen that the slope of the perovskite solar cell device prepared in Example 1 after BSH doping is smaller than that of the perovskite solar cell device prepared in Comparative Example 1 without BSH doping, indicating that the defect-assisted recombination of the perovskite solar cell device prepared in Example 1 after BSH doping is significantly reduced.

Claims

1. A perovskite solar cell doped with a sulfonylhydrazide blowing agent, the perovskite solar cell adopting an inverted structure, comprising a conductive base layer, a hole transport layer, a perovskite light absorption layer, an electron transport layer, an interface regulation layer, and a metal back electrode layer, characterized in that, The perovskite light absorption layer is FA doped with sulfonyl hydrazide foaming agent 1-x-y MA x Cs y Pb(I 1-z Br z )3, where x = 0 to 1, y = 0 to 1, z = 0 to 1.

2. The perovskite solar cell according to claim 1, characterized in that, The so-called FA 1-x-y MA x Cs y Pb(I 1- z Br z )3 is FA 0.85 MA 0.1 Cs 0.05 PbI3 or FA 0.84 MA 0.1 Cs 0.06 Pb(I 0.95 Br 0.05 )3.

3. The perovskite solar cell according to claim 1, wherein The sulfonylhydrazide blowing agent is benzenesulfonyl hydrazide, p-toluenesulfonyl hydrazide or 4,4'-oxybis(benzenesulfonyl hydrazide).

4. The perovskite solar cell according to claim 1, characterized in that, Sulfonylhydrazine blowing agent and FA 1-x- y MA x Cs y Pb(I 1-z Br z )3 has a mass ratio of 0.05:1 to 55.

5. The perovskite solar cell according to claim 1, characterized in that, The conductive base layer is ITO glass; The hole transport layer is [4-(7H-dibenzo[c,g]carbazol-7-yl)butyl]phosphonic acid, and the thickness is 5 nm to 50 nm.

6. A method for preparing a perovskite solar cell according to any one of claims 1 to 5, comprising the following steps: (1) Pretreat the conductive substrate, spin-coat the hole transport layer and anneal to obtain the hole transport layer; (2) Add sulfonylhydrazine blowing agent to FA 1-x-y MA x Cs y Pb(I 1-z Br z )3 perovskite precursor solution and stir to obtain FA 1-x-y MA x Cs y Pb(I 1-z Br z )3 perovskite precursor solution containing sulfonylhydrazine blowing agent; (3) Spin-coat FA containing a sulfonylhydrazide foaming agent on the hole transport layer prepared in step (1). 1-x-y MA x Cs y Pb(I 1- z Br z )3 perovskite precursor solution, and after the anti-solvent process and annealing treatment, a perovskite light-absorbing layer is obtained. (4) Evaporate C on the perovskite light absorption layer obtained in step (3). 60 to prepare C 60 electron transport layer; Then deposit BCP by evaporation to obtain a BCP interface control layer; then deposit Ag to obtain a perovskite solar cell doped with a sulfonylhydrazide blowing agent.

7. The method for preparing a perovskite solar cell according to claim 6, wherein The annealing temperature in step (1) is not lower than 100 °C, and the annealing time is not less than 10 min.

8. The preparation method of the perovskite solar cell according to claim 6, characterized in that, The spreading of the precursor solution is carried out by spin coating, blade coating or slot coating, wherein the rotation speed of spin coating is 500 rpm to 5000 rpm, and the spin coating time is 20 s to 45 s.

9. The method for preparing a perovskite solar cell according to claim 6, wherein The antisolvent is added for antisolvent dissolution 10 s to 25 s after the spreading of the precursor solution on the hole transport layer substrate starts, wherein the antisolvent is anhydrous ether.

10. The method for preparing a perovskite solar cell according to claim 6, wherein, The annealing temperature in step (3) is 80 to 150 °C, and the annealing time is 10 min to 30 min.

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