A method for preparing high-performance tin-containing perovskite solar cells by using bifunctional hydrazide small molecules

Abstract

This invention discloses a method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazide small molecules. The method focuses on selecting bifunctional acylhydrazide small molecules such as p-toluenesulfonylhydrazide (PTSH) and oxaloyl dihydrazide (ODZ) as additives to enhance the performance of tin-containing perovskite (ASn) solar cells. x Pb 1‑x X3) Modification of the active layer of solar cells. Compared to traditional Sn 2+ The coordination strategy of the bifunctional hydrazide small molecule selected in this invention can, in addition to coordinating with Sn... 2+ In addition to providing an antioxidant environment through coordination, Sn can also achieve... 4+ To Sn 2+ The reduction of Sn in perovskite films can be minimized. 4+ This leads to the P-type self-doping effect and defect density. The photoelectric conversion efficiency and device stability of the tin-containing perovskite solar cells prepared based on this invention are effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of perovskite solar cell technology, specifically relating to a method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazine small molecules. Background Technology

[0002] The energy crisis has spurred the development and utilization of solar energy, with solar cells being a prime example of photovoltaic (PV) conversion. Currently, further improving the photoelectric conversion efficiency of solar cells and reducing their cost per kilowatt-hour is imperative. In recent years, organic-inorganic metal halide perovskite solar cells (PSCs) have developed rapidly due to their outstanding photoelectric properties. In just fourteen years, the power conversion efficiency (PCE) of single-junction PSCs has increased from 3.8% to 25.8%, and they have passed industrial stability requirements (IEC 61215:2016 damp heat and humidity freezing tests), solidifying their position as a candidate for next-generation photovoltaic products. However, the toxicity of lead and its band gap being larger than the optimal band gap for single-junction solar cells have significantly hampered the commercialization of PSCs. Therefore, developing green and environmentally friendly perovskite materials is particularly important. Tin-containing perovskite materials stand out among many low-lead and lead-free perovskite materials due to their low toxicity, high electron mobility, and low exciton binding energy. In addition, the band gap can be flexibly adjusted by changing the Sn content, which makes it show great research potential and commercial value in perovskite tandem solar cells.

[0003] Although tin-containing PSCs have developed rapidly in recent years, with PCE reaching as high as 23.7%, they still have many problems that urgently need improvement. For example: Sn 2+ It is easily oxidized to a stable Sn 4+ The formation of high-density tin vacancies and severe p-type self-doping effects, excessively rapid thin-film crystallization leading to poor film and crystal quality, energy level mismatch between perovskite and charge transport materials, numerous surface defects, and poor stability significantly limit their photovoltaic performance and practical applications. Therefore, developing more suitable strategies to optimize the performance of tin-containing perovskite photovoltaic devices is imperative.

[0004] Additive engineering is an effective strategy for optimizing tin-containing perovskite sintered crystals (PSCs). Additives such as SnX2, large organic cations, Lewis bases, and reducing agents are commonly used in the preparation of tin-containing PSCs. These additive molecules stabilize the octahedral structure of the perovskite and inhibit the growth of Sn through coordination bonds, ionic bonds, and hydrogen bonds formed with the perovskite components. 2+The oxidation of perovskite films, optimization of perovskite film surface morphology, and suppression of single-molecule recombination in perovskite can all enhance the photoelectric properties and stability of tin-containing PSCs. In recent years, researchers have discovered that additives containing coordinating functional groups (such as aminothiourea, N,N'-methylenebisacrylamide, and phthalimide) can effectively improve the quality of tin-containing perovskite films. For example, Priya et al. used phthalimide (PTM) as an additive to optimize B-γCsSnI3 films, utilizing the lone pair electrons of the -NH and two -CO functional groups in PTM to interact with Sn. 2+ This generates coordination, reducing its oxidation to Sn. 4+ This approach reduces the defect density in the thin film, resulting in a more ordered perovskite film grain. The optimized B-γCsSnI3 perovskite solar cell exhibits significantly improved efficiency and stability (Localized Electron Density Engineering for Stabilized B-γCsSnI3-Based Perovskite Solar Cells with Efficiencies>10%[J].ACS Energy Letters,2021:1480–1489.).

[0005] Although many documents have reported Sn 2+ Coordination strategy is an effective optimization strategy, but this strategy only enhances Sn by utilizing the lone pairs of electrons in some coordination functional groups. 2+ The surrounding electron density provides a localized environment that resists oxidation, preventing Sn from oxidizing. 2+ Oxidized to Sn 4+ We know that this single antioxidant protection is unlikely to completely eliminate Sn. 4+ The generation of Sn is difficult to achieve effectively with simple ligands of this type. 4+ Convert to Sn 2+ This poses a significant threat to the long-term stability of the device. Although reducing additives can effectively reduce Sn... 4+ Convert to Sn 2+ However, its film-forming properties for tin-containing perovskite films are still unclear. Summary of the Invention

[0006] To address the problems associated with tin-containing perovskite solar cells, this invention provides a method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazine small molecules. This invention incorporates acylhydrazine small molecules into a perovskite precursor solution to form an antioxidant solution system, aiming to utilize the acylhydrazine small molecules to inhibit Sn oxidation. 2+ It can reduce oxidation, decrease the surface defect density of tin-containing perovskite thin films, and improve the overall optoelectronic performance and stability of devices.

[0007] This invention combines Sn 2+ Coordination and Sn 4+ Restore the dual strategies to jointly achieve Sn 2+ Protection and protection of Sn 4+ The reduction of Sn on the thin film surface, this dual optimization strategy is to reduce the Sn content. 4+ The high content and high defect density provide a dual guarantee, maximizing the photoelectric performance of tin-containing perovskite solar cells. To this end, this invention has selected two bifunctional hydrazide-based small molecule compounds that can be used to optimize tin-containing PSCs through a series of experiments, and provides two methods for preparing tin-containing PSCs.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazine small molecules mainly involves selecting suitable bifunctional acylhydrazine small molecules and doping them into a tin-containing perovskite system (tin-lead mixed perovskite). This method utilizes the lone pair electrons in the coordinating functional groups (S=O, C=O, -NH2) of these molecules to interact with Sn. 2+ Strong coordination occurs, inhibiting oxidation, passivating surface defects in the thin film, and improving Sn. 2+ Oxidation barrier; furthermore, Sn in the film can also be reduced by -NH2 during the annealing process of perovskite wet films. 4+ By reducing the content of P-type self-doping, the non-radiative recombination caused by deep-level defects in perovskite films can be suppressed, thereby realizing high-performance tin-lead hybrid perovskite solar cells.

[0010] This invention provides a method for preparing high-performance tin-containing perovskite solar cells using bifunctional hydrazide small molecules. The main preparation steps of the perovskite solar cell, from bottom to top, are: cleaning of ITO conductive glass, preparation of hole transport layer, preparation of tin-containing perovskite thin film, preparation of electron transport layer, and thermal deposition of metal counter electrode.

[0011] The fabrication of the perovskite solar cell specifically includes the following steps:

[0012] Step 1: First, scrub the indium tin oxide (ITO) glass with a cleaning powder, then ultrasonically clean it with pure water, acetone, isopropanol and ethanol in sequence for 20-30 minutes. Dry the cleaned ITO glass with a hot air gun and treat it with ultraviolet ozone (UV-zone) for 15-30 minutes.

[0013] Step 2: Prepare 15-25 mg / mL nickel oxide nanocrystals (NiO). xThe aqueous solution was spin-coated onto the ITO glass substrate prepared in step one at 3000-5000 rpm for 30-45 seconds. After spin-coating, the substrate was annealed at 120-150℃ for 20-30 minutes to obtain a smooth hole transport layer (HTL). The HTL was then treated with a UV-zone for 5-7 minutes.

[0014] Step 3: Dissolve cesium iodide (CsI), stannous iodide (SnI2), stannous fluoride (SnF2), and lead iodide (PbI2) in a mixed solvent of dimethyl sulfoxide (DMF) and N,N-dimethylformamide (DMSO) in a volume ratio of (3-5):1 to prepare CsSn 0.6 Pb 0.4 I3 solution; FA is prepared by dissolving formamidin hydroiodate (FAI), SnI2, SnF2, methylamine hydroiodate (MAI), and lead iodide (PbI2) in a mixed solvent of DMF and DMSO at a volume ratio of (3-5):1. 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3 solution: Take an appropriate amount of hydrazide-type small molecule compound and dissolve it in an appropriate amount of prepared tin-containing perovskite solution. After complete dissolution, filter it through a 0.22μm polytetrafluoroethylene membrane for later use.

[0015] Step 4: Spin-coat the tin-containing perovskite precursor solution prepared in Step 3 onto the HTL treated in Step 2. For CsSn 0.6 Pb 0.4 I3 and FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 For I3 perovskite solution, an appropriate amount of antisolvent needs to be added dropwise during spin coating; after spin coating, annealing is performed to obtain high-quality tin-containing perovskite thin films.

[0016] Step 5: Prepare a 20-30 mg / mL solution of zinc oxide nanocrystals (ZnO) in trifluoroethanol and a 15-25 mg / mL solution of fullerene derivatives (PC). 61 BM) Chlorobenzene solution, ZnO and PC are spin-coated sequentially onto an annealed perovskite film. 61 BM electron transport layer.

[0017] Step Six: Transfer the glass substrate with the battery transport layer deposited in Step Five to a vacuum evaporation chamber, and deposit the metal counter electrode under low vacuum conditions.

[0018] The high-performance tin-containing perovskite solar cell can be obtained by completing the above steps.

[0019] According to a preferred embodiment of the present invention, CsSn 0.6 Pb0.4 The molar ratio of CsI, SnI2, SnF2, and PbI2 in the I3 solution is 1:0.6:0.06:0.4, and the solution concentration is 0.8-1.2M, preferably 1.0M; FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 The molar ratio of FAI, SnI2, SnF2, MAI, and PbI2 in the I3 solution is 0.3:0.3:0.03:0.7:0.7, and the solution concentration is 1.6-2.4M, preferably 1.8M.

[0020] According to the present invention, the general formula of the bifunctional acylhydrazine small molecule material is R-CO-NHNH2 or R-SO-NHNH2, wherein R is one of alkyl, benzene ring, hydrazine group, or acylhydrazine group. The bifunctional acylhydrazine small molecule material can be p-toluenesulfonyl hydrazine (PTSH), oxaloyl dihydrazine (ODZ), etc., with preferred concentrations of 4 mg / mL and 3 mg / mL, respectively.

[0021] According to a preferred embodiment of the present invention, CsSn 0.6 Pb 0.4 The spin coating process for the I3 perovskite system is 4000-6000 rpm for 60-45 seconds, with an acceleration of 2000-3000 rpm / s; FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 The spin coating process for the I3 perovskite system is 5000-7000 rpm for 60-45 s with an acceleration of 2500-3500 rpm / s.

[0022] According to a preferred embodiment of the present invention, CsSn 0.6 Pb 0.4 I3 and FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 The antisolvent added during the I3 thin film preparation process is chlorobenzene, with a drop volume of 120-180 μL, and the drop times are 12-17 s and 7-9 s after the start of the respective spin coating program.

[0023] According to a preferred embodiment of the present invention, CsSn 0.6 Pb 0.4 The annealing process for the I3 perovskite system is 70℃ for 10 min followed by 105℃ for 5 min; FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 The annealing process for the I3 perovskite system is 3 minutes at 55°C followed by 7 minutes at 105°C.

[0024] According to a preferred embodiment of the present invention, the electron transport layer consists of ZnO and PC from bottom to top. 61 BM is composed of ZnO, with an optimal concentration of 25 mg / mL, and PC. 61 The preferred concentration of BM is 20 mg / mL.

[0025] According to a preferred embodiment of the present invention, the spin-coating process for the ZnO electron transport layer is: 2500-3500 rpm for 35-25 s, with an acceleration of 2000-3000 rpm / s; PC 61 The spin coating process for the BM electron transport layer is: 2000-3000 rpm for 35-25 s, with an acceleration of 2000-3000 rpm / s.

[0026] According to a preferred embodiment of the present invention, the vacuum degree of the vacuum evaporation chamber is in the range of 1×10⁻⁶. -5 ~3×10 -4 Between Pa, the metal counter electrode layer is a silver (Ag) counter electrode with a thickness of 80-120 nm, preferably 100 nm.

[0027] According to a preferred embodiment of the present invention, the tin-containing perovskite thin film prepared by the preparation method described above is denoted as CsSn. 0.6 Pb 0.4 I3:PTSH, FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3:ODZ.

[0028] According to a preferred embodiment of the present invention, except for the hole transport layer, the perovskite active layer and the electron transport layer are prepared in a protective gas atmosphere, wherein the protective gas is nitrogen.

[0029] This invention incorporates small molecule compounds with acyl (RS=O, RC=O) and amino (-NH2) functional groups as additives into tin-containing perovskite precursor solutions. The lone pair electrons in the coordination functional groups (S=O, C=O, -NH2) of these molecules interact with Sn. 2+ Coordination occurs to inhibit its oxidation; furthermore, during the annealing of perovskite wet films, Sn in the film can be reduced by -NH2. 4+ The reduced p-type self-doping content helps suppress nonradiative recombination caused by deep-level defects in perovskite films. Through numerous experiments, the inventors determined the optimal concentration of this additive within the designed concentration range. Ultimately, at this optimal concentration, a dense, flat, and pore-free tin-containing perovskite film was prepared, and the solar cells fabricated from it exhibited excellent photoelectric performance.

[0030] This invention further discloses a method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazine small molecules, wherein the high-performance tin-containing perovskite solar cells utilize the tin-containing perovskite thin film CsSn. 0.6 Pb 0.4 I3:PTSH or FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 Using I3:ODZ as the light-absorbing layer, the perovskite solar cells fabricated exhibit good photoelectric performance and stability. Among them, CsSn... 0.6 Pb 0.4 I3:PTSH exhibited an initial efficiency of 16.44%, compared to unencapsulated CsSn. 0.6 Pb 0.4 I3:PTSH devices retain approximately 93% of their initial efficiency after 60 days of storage in an inert atmosphere (argon atmosphere) at 25°C and 30% relative humidity; after 1000 hours of continuous output at maximum power point in an inert atmosphere (argon atmosphere) at 65°C and 30% relative humidity, they retain approximately 82% of their initial efficiency; and after 200 hours in an air environment, they retain approximately 85% of their initial efficiency. FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3:ODZ also exhibited an initial efficiency of 19.48% and good photostability.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] (1) The two types of tin-containing perovskite thin films provided by the present invention have a band gap of about 1.20-1.30 eV, and have the characteristics of strong light absorption, not easy to fall off and high stability.

[0033] (2) This invention provides a method for preparing high-performance tin-containing perovskite solar cells. The process is simple and convenient, widely applicable, safe and fast, and has the potential for large-scale promotion.

[0034] (3) The bifunctional hydrazide small molecule compounds selected in this invention have simple structures and are inexpensive and readily available.

[0035] (4) The method of preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazine small molecules in this invention mainly involves selecting suitable bifunctional acylhydrazine small molecules and doping them into a tin-lead mixed perovskite precursor, utilizing the coordination functional groups (S=O, C=O, -NH2) in these molecules with Sn 2+ Strong coordination interactions occur, passivating surface defects in the thin film and improving Sn. 2+Oxidation barrier; in addition, the reducing hydrazide group in the molecule can lower the Sn on the film surface. 4+ The method reduces p-type self-doping, thereby suppressing nonradiative recombination caused by deep-level defects. Ultimately, the photoelectric conversion efficiency and stability of the tin-containing perovskite solar cell prepared according to the method of this invention are significantly improved compared to the basic cell. Attached Figure Description

[0036] Figure 1 The photocurrent density-voltage curves (JV curves) of the tin-containing perovskite solar cells prepared in Examples 1, 4 and Comparative Examples 1-2 of this invention are shown, based on CsSn. 0.6 Pb 0.4 I3 and CsSn 0.6 Pb 0.4 I3:PTSH thin film (a), based on FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3 and FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3:ODZ thin film (b). The horizontal axis represents voltage, and the vertical axis represents photocurrent density.

[0037] Figure 2 These are schematic diagrams of the device structures of tin-containing perovskite solar cells prepared in Examples 1-5 and Comparative Examples 1-2 of this invention. From bottom to top, they are indium tin oxide (ITO) conductive glass, NiO... x Hole transport layer, tin-containing perovskite thin film layer, ZnO electron transport layer, PCBM electron transport layer, Ag counter electrode layer.

[0038] Figure 3 This is a schematic diagram of the preparation of tin-lead mixed perovskite thin films by two-step annealing at low and high temperatures in step three of Examples 1-5 and Comparative Examples 1-2 of the present invention.

[0039] Figure 4 CsSn prepared for Example 1 and Comparative Example 1 of this invention 0.6 Pb 0.4 Normalized PCE variation curves of I3 perovskite solar cells stored in an inert atmosphere (argon atmosphere) at 25°C and 30% relative humidity for 60 days.

[0040] Figure 5 CsSn prepared for Example 1 and Comparative Example 1 of this invention 0.6 Pb 0.4 Normalized PCE variation curve of I3 perovskite solar cell at maximum power point for 1000h under an inert atmosphere (argon atmosphere) of 65℃ and 30% relative humidity.

[0041] Figure 6 CsSn prepared for Example 1 and Comparative Example 1 of this invention 0.6 Pb 0.4 Normalized PCE variation curves of I3 perovskite solar cells placed in an air environment of 25℃ and 30% relative humidity for 200 hours.

[0042] Figure 7 FA prepared in Example 4 of the present invention 0.3 MA 0.7 Sn 0.3 Pb 0.7 Steady-state output curve of I3 perovskite thin solar cell at maximum power point.

[0043] Figure 8 The CsSn undoped with p-toluenesulfonylhydrazine prepared in step three of Comparative Example 1 and Example 1 of this invention 0.6 Pb 0.4 I3 perovskite thin films (a) and CsSn doped with p-toluenesulfonyl hydrazine 0.6 Pb 0.4 SEM image of I3 perovskite film (b).

[0044] Figure 9 The FA without oxaloyl dihydrazine doping prepared in step three of Comparative Example 2 and Example 4 of this invention 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3 perovskite thin film (a) and FA doped with oxalyl dihydrazine 0.3 MA 0.7 Sn 0.3 Pb 0.7 SEM image of I3 perovskite film (b). Detailed Implementation

[0045] To further understand the present invention, the technical solutions in the embodiments of the present invention will be described in detail below. It should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and the described embodiments are only some embodiments of the present invention, and not for limiting the claims of the present invention.

[0046] The structural formulas and general formulas of the bifunctional acylhydrazine-based small molecule materials involved in the embodiments of the present invention are shown in Table 1 below.

[0047] Table 1

[0048]

[0049] Example 1:

[0050] A high-performance tin-containing perovskite solar cell prepared using bifunctional acylhydrazine small molecules, such as Figure 2 As shown, from bottom to top, they are indium tin oxide (ITO) transparent conductive glass, nickel oxide (NiO) glass, and so on. x Hole transport layer, tin-containing perovskite films doped with hydrazide small molecules, zinc oxide (ZnO), and fullerene derivatives (PC) 61 BM) electron transport layer, Ag counter electrode layer with a thickness of 100nm.

[0051] Preparation of high-performance CsSn using p-toluenesulfonyl hydrazide (PTSH) 0.6 Pb 0.4 The fabrication process of I3 perovskite solar cells is as follows:

[0052] Step 1: Place the ITO transparent conductive glass (length × width: 1.5 × 1.5 cm) 2 First, scrub with detergent powder, then ultrasonically clean with pure water, acetone, isopropanol and ethanol for 20 minutes in sequence. Dry the cleaned ITO glass with a hot air gun and treat it under ultraviolet ozone (UV-zone) conditions for 30 minutes.

[0053] Step 2: Prepare 15 mg / mL NiO x A 30 μL aqueous solution was pipetted and spin-coated onto the ITO conductive glass prepared in step one. The specific spin-coating process was as follows: spin speed 3000 rpm, spin time 30 s, spin acceleration 2000 rpm / s. After spin-coating, the glass was annealed on a hot plate at 150°C for 25 min to form a dense hole transport layer. Before spin-coating the perovskite precursor solution, the glass was treated under ultraviolet ozone (UV-zone) conditions for 6 min. All the above preparation processes were carried out in air.

[0054] Step 3: Weigh 0.1299g CsI (0.4mmol), 0.1118g SnI2 (0.24mmol), 0.0047g SnF2 (0.024mmol), 0.0922g PbI2 (0.16mmol), and 2mg PTSH. Add a mixed solvent of 400μL DMF and 100μL DMSO, and stir at 60℃ for 12h to obtain 1.0M CsSn. 0.6 Pb 0.4 I3 perovskite precursor solution. Using a pipette, pipette 30 μL of CsSn after filtration through a 0.22 μm polytetrafluoroethylene membrane. 0.6 Pb 0.4 The I3 perovskite precursor solution was uniformly spin-coated onto the NiO treated in step two using a spin coater. xOn the hole transport layer, the specific spin-coating process was as follows: spin-coating speed 5000 rpm, spin-coating time 60 s, spin-coating acceleration 2000 rpm / s. 135 μL of the anti-solvent chlorobenzene was added dropwise at 12 s after spin-coating began. After spin-coating, the layer was placed on a hot plate for annealing. The specific annealing process was: first annealing at 70℃ for 10 min, then annealing at 105℃ for 5 min. This yielded dense CsSn. 0.6 Pb 0.4 I3:PTSH perovskite thin films. All preparation processes were carried out under a nitrogen atmosphere.

[0055] Step 4: Prepare a 25 mg / mL zinc oxide nanocrystal (ZnO) trifluoroethanol solution. Use a pipette to take 25 μL of the solution and spin-coat the CsSn prepared in step 3. 0.6 Pb 0.4 On the I3 perovskite thin film, the specific spin-coating process was as follows: spin-coating speed 2500 rpm, spin-coating time 25 s, spin-coating acceleration 2000 rpm / s. A ZnO electron transport layer was formed. The above preparation process was carried out under a nitrogen atmosphere.

[0056] Step 5: Prepare a 20 mg / mL solution of fullerene derivative (PC). 61 BM) Chlorobenzene solution: 20 μL of solution was pipetted and spin-coated onto the ZnO electron transport layer prepared in step four. Specific spin-coating process: spin-coating speed 2000 rpm, spin-coating time 30 s, spin-coating acceleration 2000 rpm / s. This forms PC. 61 BM electron transport layer. The above preparation process was carried out under a nitrogen atmosphere.

[0057] Step Six: Transfer the processed components from Step Five to the vacuum evaporation chamber, and wait until the vacuum level of the chamber is less than 3 × 10⁻⁶. -4 After Pa, the Ag counter electrode layer is deposited. The specific deposition process is as follows: the deposition rate for 0-5nm is... The deposition rate of 5-10nm is The deposition rate for 10-30nm is The deposition rate for 30-100nm is The thickness of the co-deposited Ag was 100 nm.

[0058] like Figure 1 As shown in (a) and Table 2, under standard test conditions (AM 1.5G), Example 1 is based on CsSn 0.6 Pb 0.4 The reverse scan PCE of the solar cell device fabricated from I3:PTSH perovskite thin film is 16.44%, V oc It is 0.817V, J sc 28.35 mA·cm-2 FF is 71.01%. For example... Figure 4 As shown, the unencapsulated CsSn prepared in Example 1 0.6 Pb 0.4 I3:PTSH devices, when stored at 25°C and 30% relative humidity in an inert atmosphere (argon atmosphere) for 60 days, retain approximately 93% of their initial efficiency; Figure 5 As shown, CsSn 0.6 Pb 0.4 I3:PTSH devices retain approximately 82% of their initial efficiency after 1000 hours of continuous output at maximum power point in an inert atmosphere (argon atmosphere) at 65℃ and 30% relative humidity; For example... Figure 6 As shown, CsSn 0.6 Pb 0.4 I3:PTSH devices can maintain about 85% of their initial efficiency even after being placed in air for 200 hours.

[0059] Example 2:

[0060] A method for preparing a tin-containing perovskite solar cell is described in Example 1, except that: in step three, CsSn 0.6 Pb 0.4 The PTSH content in the I3 perovskite precursor solution was 1 mg. Other steps and conditions were the same as in Example 1.

[0061] As shown in Table 2, under standard test conditions (AM 1.5G), Example 2 is based on CsSn 0.6 Pb 0.4 The reverse scanning PCE of the solar cell device fabricated from I3 perovskite thin film was 14.81%, V oc It is 0.808V, J sc 27.02 mA·cm -2 FF was 67.86%.

[0062] Example 3:

[0063] A method for preparing a tin-containing perovskite solar cell is described in Example 1, except that: in step three, CsSn 0.6 Pb 0.4 The PTSH content in the I3 perovskite precursor solution was 3 mg. Other steps and conditions were the same as in Example 4.

[0064] As shown in Table 2, under standard test conditions (AM 1.5G), Example 3 is based on CsSn. 0.6 Pb 0.4 The reverse scanning PCE of the solar cell device fabricated from I3 perovskite thin film was 13.74%, V oc It is 0.833V, Jsc 28.89 mA·cm -2 The FF value was 57.09%.

[0065] Comparative Example 1:

[0066] A method for preparing a tin-containing perovskite solar cell is described in Example 1, except that: in step three, CsSn 0.6 Pb 0.4 PTSH was not added to the I3 perovskite precursor solution. Other steps and conditions were the same as in Example 1.

[0067] like Figure 1 As shown in (a) and Table 2, under standard test conditions (AM 1.5G), Comparative Example 1 is based on CsSn 0.6 Pb 0.4 The reverse scanning PCE of the solar cell device fabricated from I3 perovskite thin film was 12.36%, V oc It is 0.752V, J sc 26.46 mA·cm -2 FF is 62.12%. For example... Figure 4 As shown, the unencapsulated CsSn prepared in Comparative Example 1 0.6 Pb 0.4 The I3 device, stored at 25°C and 30% relative humidity in an inert atmosphere (argon atmosphere) for 60 days, retained only 37% of its initial efficiency; Figure 5 As shown, CsSn 0.6 Pb 0.4 The efficiency of the I3 device decreased to 53% of its initial efficiency after 270 hours of continuous output at maximum power point in an inert atmosphere (argon atmosphere) at 65°C and 30% relative humidity; Figure 6 As shown, CsSn 0.6 Pb 0.4 The efficiency of the I3 device drops drastically to about 10% of its initial efficiency after being placed in air for only 20 hours.

[0068] contrast Figure 1 (a) based on CsSn 0.6 Pb 0.4 I3 and CsSn 0.6 Pb 0.4 Performance data of I3:PTSH thin films show that the addition of an appropriate amount of PTSH significantly improves the performance of CsSn. 0.6 Pb 0.4 Photovoltaic conversion efficiency of I3 perovskite solar cell devices; comparison Figures 4-6 The stability data shows that the addition of an appropriate amount of PTSH greatly improves the stability of CsSn. 0.6 Pb 0.4Stability of I3 perovskite solar cell devices.

[0069] Comparative Example 1: CsSn without p-toluenesulfonylhydrazine doping prepared in step three 0.6 Pb 0.4 I3 perovskite thin film and CsSn doped with p-toluenesulfonyl hydrazine prepared in step three of Example 1. 0.6 Pb 0.4 SEM images of the I3:PTSH perovskite thin film are shown below. Figure 8 As shown in (a) and (b), it can be seen that the addition of an appropriate amount of PTSH makes CsSn 0.6 Pb 0.4 The I3 perovskite thin film has a smoother morphology and is free of pinholes, with a larger crystal size, which greatly improves its light-harvesting ability and device performance.

[0070] Example 4:

[0071] A high-performance tin-containing perovskite solar cell prepared using bifunctional acylhydrazide small molecules, such as Figure 2 As shown, from bottom to top, they are indium tin oxide (ITO) transparent conductive glass, nickel oxide (NiO) glass, and so on. x Hole transport layer, tin-containing perovskite films doped with hydrazide small molecules, zinc oxide (ZnO), and fullerene derivatives (PC) 61 BM) electron transport layer, Ag counter electrode layer with a thickness of 100nm.

[0072] Preparation of high-performance FA using oxaloyl dihydrazide (ODZ) 0.3 MA 0.7 Sn 0.3 Pb 0.7 The fabrication process of the I3 perovskite solar cell is as described in Example 1, except that: in step three, the perovskite precursor solution consists of 0.0464 g FAI (0.27 mmol), 0.1006 g SnI2 (0.27 mmol), 0.0042 g SnF2 (0.027 mmol), 0.1002 g MAI (0.63 mmol), 0.2904 g PbI2 (0.63 mmol), and 1.5 mg ODZ; the solvent is a mixed solvent of 400 μL DMF and 100 μL DMSO; the concentration of the perovskite precursor solution is 1.8 M; the spin coating process is a spin coating speed of 6500 rpm, a spin coating time of 45 s, and a spin coating acceleration of 3500 rpm / s; 135 μL of the anti-solvent chlorobenzene is added dropwise 7 s after the start of spin coating; the annealing process is to first anneal at 55 °C for 3 min and then anneal at 105 °C for 7 min. The other steps and conditions are the same as in Example 1.

[0073] like Figure 1As shown in (b) and Table 2, under standard test conditions (AM 1.5G), Example 4 is based on FA. 0.3 MA 0.7 Sn 0.3 Pb 0.7 The reverse scanning PCE of the solar cell device fabricated from I3:ODZ perovskite thin film is 19.48%, V oc It is 0.848V, J sc 32.16 mA·cm -2 FF is 71.45%. For example... Figure 7 As shown, under standard test conditions (AM 1.5G),

[0074] Example 4 is based on FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 Solar cell devices fabricated from I3:ODZ perovskite thin films exhibit stable maximum power output, indicating that FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3:ODZ perovskite exhibits good photostability.

[0075] Example 5:

[0076] A method for fabricating a tin-containing perovskite solar cell is described in Example 4, except that in step three, FA... 0.3 MA 0.7 Sn 0.3 Pb 0.7 The ODZ content in the I3 perovskite precursor solution was 3 mg, and the other steps and conditions were the same as in Example 4.

[0077] As shown in Table 2, under standard test conditions (AM 1.5G), this embodiment is based on FA. 0.3 MA 0.7 Sn 0.3 Pb 0.7 The reverse scanning PCE of the solar cell device fabricated from I3 perovskite thin film was 18.37%, V oc It is 0.827V, J sc 31.94 mA·cm -2 FF was 69.52%.

[0078] Comparative Example 2:

[0079] A method for fabricating a tin-containing perovskite solar cell is described in Example 4, except that in step three, FA... 0.3 MA 0.7 Sn 0.3 Pb0.7 ODZ was not added to the I3 perovskite precursor solution, and the other steps and conditions were the same as in Example 4.

[0080] like Figure 1 As shown in (b) and Table 2, under standard test conditions (AM 1.5G), this embodiment is based on FA. 0.3 MA 0.7 Sn 0.3 Pb 0.7 The reverse scanning PCE of the solar cell device fabricated from I3 perovskite thin film was 17.28%, V oc It is 0.793V, J sc 31.70 mA·cm -2 FF was 68.72%.

[0081] contrast Figure 1 (b) based on FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3 and FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 Performance data of I3:ODZ thin films show that the addition of an appropriate amount of ODZ significantly improves FA. 0.3 MA 0.7 Sn 0.3 Pb 0.7 Photovoltaic conversion efficiency of I3 perovskite solar cell devices.

[0082] Comparative Example 2: FA without oxaloyl dihydrazine doping prepared in step three 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3 perovskite thin film and FA doped with oxaloyl dihydrazine prepared in step three of Example 4 0.3 MA 0.7 Sn 0.3 Pb 0.7 SEM images of the I3:ODZ perovskite thin film are shown below. Figure 9 As shown in (a) and (b), it can be seen that the addition of an appropriate amount of ODZ makes FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3 perovskite films have fewer impurities and larger crystal sizes, which greatly improves their light-harvesting ability and device performance.

[0083] Figure 3In Examples 1-5 and Comparative Examples 1-2, tin-lead mixed perovskite (CsSn) was prepared by a two-step annealing process involving low temperature (55-75℃) and high temperature (100-110℃) in step three. 0.6 Pb 0.4 I3, FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 Schematic diagram of the I3 thin film. It can be seen that the tin-lead mixed perovskite wet film underwent a crystallization phase transition process during low-temperature annealing, generating some Sn during the phase transition. 4+ Then, annealing at high temperature was performed to achieve a Sn 4+ To Sn 2+ The transformation process reduces the amount of Sn in the thin film. 4+ The content of Sn. Therefore, a two-step annealing process can achieve two objectives in the tin-lead mixed perovskite system: (1) low-temperature annealing can realize the phase transformation of tin-lead mixed perovskite, and a suitable temperature can effectively control the crystallization rate of perovskite; (2) high-temperature annealing can make uncoordinated bifunctional hydrazide small molecules act as reducing agents to reduce Sn. 4+ Restore to Sn 2+ .

[0084] The photoelectric performance parameters of the tin-containing perovskite solar cells prepared in Examples 1-5 and Comparative Examples 1-2 are shown in Table 2 below.

[0085] Table 2

[0086]

[0087]

Claims

1. A method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazide small molecules, characterized in that, The main fabrication steps of a perovskite solar cell, from bottom to top, are: cleaning of the conductive glass, preparation of the hole transport layer, preparation of the tin-containing perovskite thin film, preparation of the electron transport layer, and thermal deposition of the metal counter electrode; the specific fabrication steps of the perovskite solar cell include the following: Step 1: First, scrub the ITO glass with a cleaning powder, then ultrasonically clean it in sequence with pure water, acetone, isopropanol and ethanol. Dry the cleaned ITO glass with a hot air gun and treat it with a UV-zone. Step 2: Prepare 15-25 mg / mL nickel oxide nanocrystals (NiO) x The aqueous solution was spin-coated onto the ITO glass substrate prepared in step one at 3000-5000 rpm for 30-45 seconds. After spin-coating, the substrate was annealed at 120-150℃ for 20-30 minutes to obtain a smooth hole transport layer. The substrate was then treated with a UV-zone for 5-7 minutes. Step 3: Dissolve the bifunctional hydrazide-based small molecule material and the tin-containing perovskite material together in a polar solvent, and add stannous fluoride as an antioxidant. Stir continuously until transparent to obtain a tin-containing perovskite precursor solution, filter it through a 0.22μm polytetrafluoroethylene membrane and set it aside for later use. Step 4: Spin-coat the tin-containing perovskite precursor solution prepared in Step 3 onto the hole transport layer prepared in Step 2. During the spin-coating process, add the anti-solvent chlorobenzene as needed. After spin-coating, anneal to obtain the tin-containing perovskite film. Step 5: Prepare a 20-30 mg / mL solution of zinc oxide nanocrystals (ZnO) in trifluoroethanol and a 15-25 mg / mL solution of fullerene derivative PC. 61 BM chlorobenzene solution was used to spin-coat ZnO and PC sequentially onto an annealed tin-containing perovskite film. 61 BM electron transport layer; Step Six: Transfer the glass substrate with the battery transport layer deposited in Step Five to a vacuum evaporation chamber, and evaporate the metal counter electrode under low vacuum conditions; The high-performance tin-containing perovskite solar cell can be obtained by completing the above steps.

2. The method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazide small molecules according to claim 1, characterized in that, In step three, the general formula for bifunctional hydrazide-based small molecule materials is R-CO-NHNH2 or R-SO-NHNH2, where R is one of alkyl, benzene ring, hydrazine group, or hydrazide group, including PTSH and ODZ; the general formula for tin-containing perovskite materials is ASN. x Pb 1-x X3, including CsSn 0.6 Pb 0.4 I3-Inorganic Tin-Lead Mixed System, FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3-Organic-Inorganic Tin-Lead Mixed System.

3. The method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazide small molecules according to claim 2, characterized in that, In step three, the mass concentrations of PTSH and ODZ are 0-6 mg / mL.

4. The method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazide small molecules according to claim 1, characterized in that, In step three, the polar solvents are DMF and DMSO.

5. The method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazide small molecules according to claim 1, characterized in that, Step three involves dissolving CsI, SnI2, SnF2, and PbI2 in a mixed solvent of DMF and DMSO at a volume ratio of (3-5):1 to prepare CsSn 0.6 Pb 0.4 I3 solution; prepare FA by dissolving FAI, SnI2, SnF2, MAI, and PbI2 in a mixed solvent of DMF and DMSO at a volume ratio of (3-5):

1. 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3 solution; dissolve the hydrazide-type small molecule compounds separately in the prepared tin-containing perovskite solution, filter through a 0.22μm polytetrafluoroethylene membrane after complete dissolution, and then use for later use.

6. The method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazide small molecules according to claim 5, characterized in that, For CsSn 0.6 Pb 0.4 For the I3 perovskite system, the spin coating speed and time are 4000-6000 rpm and 60-45 s; for FA... 0.3 MA 0.7 Sn 0.3 Pb 0.7 For the I3 perovskite system, the spin coating speed and time are 5000-7000 rpm and 60-45s.

7. The method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazide small molecules according to claim 5, characterized in that, Spin-coated CsSn 0.6 Pb 0.4 I3 and FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 During the process of preparing the I3 perovskite solution, an antisolvent, CsSn, needs to be added dropwise. 0.6 Pb 0.4 I3 and FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 During the preparation of I3 thin films, the amount of chlorobenzene, the antisolvent, added was 120-180 μL, and the addition time was 12-17 s and 7-9 s after the start of the respective spin coating program.

8. The method for preparing high-performance tin-containing perovskite solar cells using bifunctional acylhydrazide small molecules according to claim 1, characterized in that, In step four, CsSn 0.6 Pb 0.4 The I3 film annealing procedure is 65-75℃ for 8-12 min followed by 95-110℃ for 5-7 min; FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 The I3 thin film annealing procedure is 50-70℃ for 3-5 min, followed by 100-110℃ for 7-10 min.

9. The tin-containing perovskite thin film prepared by the preparation method according to any one of claims 1-8, characterized in that, The tin-containing perovskite film is CsSn. 0.6 Pb 0.4 I3:PTSH, FA 0.3 MA 0.7 Sn 0.3 Pb 0.7 I3:ODZ.

10. A high-performance tin-containing perovskite solar cell, characterized in that, The high-performance tin-containing perovskite solar cell uses the tin-containing perovskite thin film of claim 9 as the light-absorbing layer.

Images