Perovskite solar cell passivated by a sulfur-containing passivation agent

Abstract

The application discloses a perovskite solar cell passivated by a sulfur-containing passivation agent, and a passivation layer is formed on an APbX3 peroviskite film by using the sulfur-containing passivation agent. 2+ S in the sulfur-containing passivation agent interacts with the weakly acidic Pb as a Lewis base, and H in the passivation molecule can form a hydrogen bond with the nearby iodide to further strengthen the interaction, reduce the surface defect density of the APbX3 peroviskite film, improve the interface energy level matching between the peroviskite and the charge transport layer, reduce the environmental resistance of the peroviskite solar cell, and greatly improve the photoelectric conversion efficiency and stability of the APbX3 peroviskite solar cell.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a perovskite solar cell that passivates surface defects of perovskite thin films using a sulfur-containing passivating agent. Background Technology

[0002] Over the past decade, perovskite solar cells (PSCs) have been extensively studied as a promising alternative to traditional photovoltaic (PV) technologies. Halide perovskite materials have attracted widespread attention due to their excellent photoelectric properties, such as tunable bandgap, high absorption coefficient, and ultra-high carrier mobility, advantages that are highly attractive in PV technology. For example, inorganic perovskites, with a bandgap of 1.73 eV, can be used as top cells in perovskite tandem / silicon-based tandem solar cells. Furthermore, pin-type PSCs are generally more stable than nip-type PSCs, often involving the use of hygroscopic dopants. Currently, almost all records for single-junction PSC efficiency are based on nip architectures, where the standard doped hole transport layer poses a challenge to simultaneously achieving high efficiency and excellent operational reliability. Pin-cell structures are an attractive option for PSC commercialization due to their low-temperature processing and compatibility with large-scale manufacturing. Since a key application of pin cells is the development of multi-junction series cells capable of breaking the single-junction SQ limit, the development of high-voltage output pin-structured cells is crucial for the industrialization of PSCs.

[0003] Perovskite-hole transport layer (PSC) devices have two key points at the interfaces of the perovskite / electron transport layer and the perovskite / hole transport layer. These interface contacts are crucial to device performance, including photoelectric conversion efficiency, current-voltage hysteresis, and stability. Therefore, achieving high-quality interface contacts is key to achieving high PSC performance. During the fabrication of perovskite thin films, due to I... - The volatile nature of these molecules makes them prone to forming defects on the surface of perovskite films. These charged Ig molecules... - Vacant and undermatched Pb 2+ As recombination centers, perovskite defects terminate the charge lifetime before free charge carriers can transfer to adjacent charge transport layers. Furthermore, surface defects possess deep energy levels, which can lead to band bending, narrowing the energy difference between the Fermi levels of the charge transport layers and causing a mismatch between the interface energy levels and the output voltage. Poor interface energy level matching between the perovskite and the charge transport layer affects charge extraction and efficiency improvement. Moreover, these defective sites are prone to trapping moisture from the environment, initiating phase transitions or chemical degradation, severely impacting the long-term stability of the device. Therefore, perovskite surface modification is crucial for achieving high-power conversion efficiency devices. Thus, effective surface and interface modification is an important research direction for fabricating efficient and stable perovskite solar cells. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a perovskite solar cell passivated with a sulfur-containing passivating agent. This reduces the surface defect density of the perovskite thin film, improves the interface energy level matching between the perovskite and the charge transport layer, reduces the tolerance of the external environment to the perovskite solar cell, and improves the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0005] To achieve the above objectives, the perovskite solar cell passivated with a sulfur-containing passivating agent provided by the present invention comprises, from bottom to top, a transparent conductive glass, a hole transport layer, a perovskite absorber layer, a sulfur-containing interface modification layer, an electron transport layer, and a metal electrode, stacked sequentially; or comprises, from bottom to top, a transparent conductive glass, an electron transport layer, a perovskite absorber layer, a sulfur-containing interface modification layer, a hole transport layer, and a metal electrode; wherein, the perovskite absorber layer is an APbX3 perovskite thin film with a perovskite structure, wherein A is cesium ions (Cs). + ), formamidinium ion (FA) + ) and methylamine ions (MA + X can be any one or more of the following, where X is any one or more halide anions, such as chlorine (Cl). - ), bromine (Br) - ), iodine (I - The sulfur-containing interface modification layer is formed by depositing a sulfur-containing passivating agent onto the perovskite absorber layer via spin coating.

[0006] The aforementioned sulfur-containing passivating agents include any one of 2-mercapto-1-methylimidazolium, 1-[(1-methyl-1H-imidazol-2-yl)sulfonyl]-1H-benzotriazole, 2-mercapto-1H-benzimidazole-5-carboxylic acid, 5-(difluoromethoxy)-2-mercapto-1H-benzimidazole, 4-chloro-1-(dimethylaminosulfonyl)-5-(p-tolyl)imidazol-2-carboxynitrile, benzylchloromethyl sulfide, 4,4'-diaminodiphenyl disulfide, bis(trimethylsilylmethyl) sulfide, 2,2'-disulfide dipyridine, thiocarbonate O,O'-di-2-pyridine ester, dibenzyl disulfide, 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol, bidithiophene, O-benzylhydroxylamine hydrochloride, benzyl isothiourea hydrochloride, benzylchloromethyl sulfide, and benzyl methyl disulfide. The structural formula is as follows:

[0007]

[0008] 2-Mercapto-1-methylimidazolium

[0009]

[0010] 1-[(1-methyl-1H-imidazol-2-yl)sulfonyl]-1H-benzotriazole

[0011]

[0012] 2-Mercapto-1H-benzimidazole-5-carboxylic acid

[0013]

[0014] 5-(difluoromethoxy)-2-mercapto-1H-benzimidazole

[0015]

[0016] 4-Chloro-1-(dimethylaminosulfonyl)-5-(p-tolyl)imidazol-2-carboxynitrile

[0017]

[0018] benzyl methyl sulfide

[0019]

[0020] Chloromethyl phenyl sulfide

[0021]

[0022] benzyl methyl disulfide

[0023]

[0024] 4,4'-Diaminodiphenyldisulfide

[0025]

[0026] bis(trimethylsilylmethyl)sulfide

[0027]

[0028] 2,2'-Dithiodipyridine

[0029]

[0030] O,O'-di-2-pyridine thiocarbonate

[0031]

[0032] Dibenzyl disulfide

[0033]

[0034] 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol

[0035]

[0036] Dithiophene

[0037]

[0038] O-Benzylhydroxyamine hydrochloride

[0039]

[0040] Benzyl isothiourea hydrochloride

[0041] The method for preparing the perovskite solar cell of the present invention includes the following steps:

[0042] Step 1: Indium tin oxide (ITO) conductive glass or fluorine-doped tin oxide (FTO) conductive glass is ultrasonically cleaned in acetone, isopropanol and ethanol for 10-30 minutes each, and then dried with nitrogen to obtain clean transparent conductive glass.

[0043] Step 2: Using spin coating, a hole transport layer solution with a concentration of 1-30 mg / mL is spin-coated onto a transparent conductive glass at a spin speed of 1000-5000 rpm / min for 40 s. After spin coating, annealing is performed at a temperature of 100-200℃ for 10-40 min to obtain a hole transport layer with a thickness of 10-60 nm. The hole transport layer is made of any one of the following: NiO, WO3, MoO3, poly(9-vinylcarbazole) (PVK), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), polymer of 3-hexylthiophene (P3HT), poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS), CuSCN, N′-di(phenyl)benzidine (NPB), and 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (spiro-OMeTAD). The solvent used is any one or a mixture of several of the following: deionized water, anhydrous ethanol, chlorobenzene, isopropanol, acetonitrile, and anisole.

[0044] Step 3: Dissolve the APbX3 precursor in a solvent by molar ratio and stir at room temperature for more than 6 hours to obtain a perovskite precursor solution with a concentration of 0.5-1.5 mol / L; wherein, A is a methylamine cation (MA + ), formamidinium cation (FA) + ), cesium cation (Cs) + ), rubidium cations (Rb + Any one or more of the following, where X is a halide anion (I2). - ,Br - Cl -The solvent is any one or a mixture of dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, and N-methylpyrrolidone. The obtained perovskite precursor solution is spin-coated onto the electron transport layer of step 1. The spin-coating process consists of two stages: the first stage has a spin speed of 500–1500 rpm / min and a spin-coating time of 5–30 s; the second stage has a spin speed of 2000–5000 rpm / min and a spin-coating time of 30–50 s; annealing is performed after spin-coating; the annealing temperature is 100–210℃ and the annealing time is 5–40 min, thus obtaining the perovskite absorber layer.

[0045] Step 4: Dissolve the sulfur-containing passivating agent in one or more of the following: chlorobenzene, isopropanol, toluene, ethyl acetate, etc., to prepare a passivating agent solution with a concentration of 1-20 mg / mL. Spin-coat the passivating agent solution onto the perovskite absorption layer at a speed of 2000-6000 rpm / min for 20-80 s. Then, place it in a low vacuum environment and let it stand for 10-60 min. After standing, a passivation layer, i.e., a sulfur-containing interface modification layer, is formed on the perovskite absorption layer. The chlorobenzene, isopropanol, toluene, ethyl acetate, etc., are analytical grade reagents.

[0046] Step 5: Spin-coat an electron transport layer solution with a concentration of 1–20 mg / mL directly onto the sulfur-containing interface modification layer at a rotation speed of 2000–4000 rpm / min for 20–40 s to obtain an electron transport layer with a thickness of 20–50 nm. The electron transport layer material is TiO2, SnO2, methyl (6,6)-phenyl-C61-butyrate (PCBM), and C... 60 The solvent used is any one of Nb2O3, 1,3,5-tris-(N-phenyl-imidazolium-2-yl)benzene (TBPi), and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the solvent used is any one or a mixture of several of chlorobenzene, isopropanol, anisole, ethyl acetate, etc.

[0047] Step 6: Deposit Au, Ag, or Cu metal electrodes with a thickness of 80–100 nm on the electron transport layer to obtain a titanium dioxide solar cell.

[0048] The beneficial effects of this invention are as follows:

[0049] Compared with the prior art, the present invention forms a passivation layer on an APbX3 perovskite film by using a sulfur-containing passivating agent. The sulfur in the sulfur-containing passivating agent acts as a Lewis base and reacts with the poorly coordinated weakly acidic Pb. 2+The interaction between the passivating molecules and the hydrogen bonds formed by the H atoms in the passivating molecules with similar iodides further enhances this effect. This reduces the surface defect density of the APbX3 perovskite film while improving the interfacial energy level matching between the inorganic perovskite and the charge transport layer. This reduces the environmental tolerance of the perovskite solar cell, significantly improving the photoelectric conversion efficiency and stability of the APbX3 perovskite solar cell. The sulfur-containing passivating agent and passivation method of this invention are applicable to both conventional and inverted perovskite solar cells. Attached Figure Description

[0050] Figure 1 Trans-all-inorganic CsPbI prepared in Comparative Example 1 and Examples 1, 6, and 14 3-x Br x Comparison of JV curves for perovskite solar cells.

[0051] Figure 2 Trans-inorganic CsPbI prepared in Comparative Example 1 and Example 1 3-x Br x Ultraviolet photoelectron spectroscopy (UPS) of perovskite thin films.

[0052] Figure 3 Trans-inorganic CsPbI prepared in Comparative Example 1 and Example 1 3-x Br x Fluorescence (PL) spectrum of perovskite thin film.

[0053] Figure 4 Trans-inorganic CsPbI prepared in Comparative Example 1 and Example 1 3-x Br x Time-resolved fluorescence (TRPL) spectrum of perovskite thin film.

[0054] Figure 5 Trans-inorganic CsPbI prepared in Comparative Example 1 and Example 1 3-x Br x A comparison chart of the humidity stability of perovskite solar cell devices.

[0055] Table 1 shows the performance statistics of the perovskite solar cell devices prepared in the comparative examples and embodiments. Detailed Implementation

[0056] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited to these embodiments.

[0057] This invention provides a reverse inorganic perovskite solar cell passivated with a sulfur-containing passivating agent. By using a sulfur-containing passivating agent to form a passivation layer on an APbX3 perovskite thin film, the efficiency and stability of the perovskite solar cell are effectively improved. The cell structure, from bottom to top, consists of a transparent conductive glass, a hole transport layer, a perovskite absorber layer, a sulfur-containing interface modification layer, an electron transport layer, and a metal electrode. The entire fabrication method includes the following steps:

[0058] Step 1: Clean the indium tin oxide (ITO) conductive glass or fluorine-doped tin oxide (FTO) conductive glass sequentially by ultrasonic cleaning in acetone, isopropanol and ethanol for 10-30 minutes each, and then dry it with nitrogen to obtain clean transparent conductive glass.

[0059] Step 2: Using spin coating, a hole transport layer solution with a concentration of 1–20 mg / mL is spin-coated onto a transparent conductive glass substrate at a spin speed of 1000–4000 rpm / min for 40 s. After spin coating, annealing is performed at a temperature of 100–150℃ for 10–40 min to obtain a hole transport layer with a thickness of 20–50 nm. The hole transport layer material is NiO, WO3, MoO3, PVK, PTAA, P3HT, PEDOT:PSS, CuSCN, or NPB, and the solvent used is any one or a mixture of several of the following: deionized water, anhydrous ethanol, chlorobenzene, and isopropanol anisole.

[0060] Step 3: Dissolve the APbX3 precursor in a solvent by molar ratio, and stir at room temperature for more than 6 hours to obtain a perovskite precursor solution with a concentration of 0.5-1.5 mol / L; wherein, A is a methylamine cation (MA + ), formamidinium cation (FA) + ), cesium cation (Cs) + ), rubidium cations (Rb + Any one or more of the following, where X is a halide anion (I2). - ,Br - Cl - The solvent is any one or a mixture of dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, and N-methylpyrrolidone. The obtained perovskite precursor solution is spin-coated onto the electron transport layer of step 1. The spin-coating process consists of two stages: the first stage has a spin speed of 500–1500 rpm / min and a spin-coating time of 5–30 s; the second stage has a spin speed of 2000–5000 rpm / min and a spin-coating time of 30–50 s; annealing is performed after spin-coating; the annealing temperature is 100–210℃ and the annealing time is 5–40 min, thus obtaining the perovskite absorber layer.

[0061] Step 4: Dissolve the sulfur-containing passivating agent in any one or a mixture of chlorobenzene, isopropanol, and ethyl acetate to prepare a passivating agent solution with a concentration of 1-10 mg / mL. Spin-coat the passivating agent solution onto the perovskite absorber layer at a speed of 3000-5000 rpm / min for 30-50 seconds. Then place it in a low vacuum environment to dry for 10-60 minutes. After drying, a passivation layer, namely a sulfur-containing interface modification layer, is formed on the perovskite absorber layer. The sulfur-containing passivating agent comprises any one of 2-mercapto-1-methylimidazolium, 1-[(1-methyl-1H-imidazol-2-yl)sulfonyl]-1H-benzotriazole, 2-mercapto-1H-benzimidazole-5-carboxylic acid, 5-(difluoromethoxy)-2-mercapto-1H-benzimidazole, 4-chloro-1-(dimethylaminosulfonyl)-5-(p-tolyl)imidazol-2-carboxynitrile, benzylchloromethyl sulfide, 4,4'-diaminodiphenyl disulfide, bis(trimethylsilylmethyl) sulfide, 2,2'-disulfide dipyridine, O,O'-di-2-pyridine thiocarbonate, dibenzyl disulfide, 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol, bidithiophene, O-benzylhydroxylamine hydrochloride, benzyl isothiourea hydrochloride, benzylchloromethyl sulfide, and benzyl methyl disulfide. The chlorobenzene, isopropanol, and ethyl acetate were analytical grade reagents.

[0062] Step 5: Spin-coat an electron transport layer solution with a concentration of 1–20 mg / mL directly onto the sulfur-containing interface modification layer at a spin speed of 2000–4000 rpm / min for 20–40 s to obtain an electron transport layer with a thickness of 20–50 nm; the electron transport layer material includes PCBM and C. 60 Any one of Nb2O3, TBPi, and BCP, and a mixture of any one or more of chlorobenzene, isopropanol, anisole, and ethyl acetate in the solvent.

[0063] Step 6: Deposit Au, Ag, or Cu metal electrodes with a thickness of 80–100 nm on the electron transport layer to obtain a perovskite solar cell.

[0064] Comparative Example 1

[0065] Step 1: The FTO conductive glass is ultrasonically cleaned in acetone, isopropanol and ethanol for 30 minutes each, and then dried with nitrogen to obtain clean FTO conductive glass.

[0066] Step 2: NiO nanoparticles were dispersed in deionized water to prepare a NiO solution with a concentration of 10 mg / mL. The solution was then spin-coated onto FTO conductive glass at a spin speed of 3000 rpm / min for 40 s. After spin-coating, the glass was annealed at a temperature of 120℃ for 20 min to obtain a hole transport layer with a thickness of 30 nm.

[0067] Step 3: Dissolve CsI, DMAI, PbI2, and PbBr2 in a molar ratio of 3.00:1:2.85:0.15 in a mixture of dimethylformamide and dimethyl sulfoxide in a volume ratio of 9:1. Stir the mixture on a stirring table for at least 6 hours to obtain a CsPbI2 solution with a concentration of 0.6 mol / L. 3-x Br x Perovskite precursor solution; the prepared CsPbI 3-x Br x The perovskite precursor solution was spin-coated onto the hole transport layer prepared in step 2. The spin-coating process consisted of two stages: the first stage had a spin speed of 1000 rpm / min and a spin-coating time of 10 s; the second stage had a spin speed of 4000 rpm / min and a spin-coating time of 30 s; after spin-coating, the perovskite absorber layer was obtained by hot-setting at 210℃ for 5 min.

[0068] Step 4: Spin-coat a 20 mg / mL PCBM chlorobenzene solution directly onto the sulfur-containing interface modification layer at a spin speed of 2000 rpm / min for 30 s to obtain an electron transport layer with a thickness of 50 nm.

[0069] Step 5: Deposit a 120nm thick Ag film on the electron transport layer of step 4, resulting in a cell area of ​​0.09cm². 2 Thus, an inverse perovskite solar cell was obtained.

[0070] Example 1

[0071] Step 1: The FTO conductive glass is ultrasonically cleaned in acetone, isopropanol and ethanol for 30 minutes each, and then dried with nitrogen to obtain clean FTO conductive glass.

[0072] Step 2: NiO nanoparticles were dispersed in deionized water to prepare a NiO solution with a concentration of 10 mg / mL. The solution was then spin-coated onto FTO conductive glass at a spin speed of 3000 rpm / min for 40 s. After spin-coating, the glass was annealed at a temperature of 120℃ for 20 min to obtain a hole transport layer with a thickness of 30 nm.

[0073] Step 3: Dissolve CsI, DMAI, PbI2, and PbBr2 in a molar ratio of 3.00:1:2.85:0.15 in a mixture of dimethylformamide and dimethyl sulfoxide in a volume ratio of 9:1. Stir the mixture on a stirring table for at least 6 hours to obtain a CsPbI2 solution with a concentration of 0.6 mol / L. 3-x Br x Perovskite precursor solution; the prepared CsPbI 3-x Br xThe perovskite precursor solution was spin-coated onto the hole transport layer prepared in step 2. The spin-coating process consisted of two stages: the first stage had a spin speed of 1000 rpm / min and a spin-coating time of 10 s; the second stage had a spin speed of 4000 rpm / min and a spin-coating time of 30 s; after spin-coating, the perovskite absorber layer was obtained by hot-setting at 210℃ for 5 min.

[0074] Step 4: Add 2-mercapto-1-methylimidazole to chlorobenzene to prepare a passivating agent solution with a concentration of 3 mg / mL. Spin-coat this solution evenly onto the perovskite absorber layer at a speed of 4000 rpm / min for 40 s; then place it in a low vacuum environment to dry for 30 min. After drying, a passivation layer, i.e., a sulfur-containing interface modification layer, is formed on the perovskite absorber layer.

[0075] Step 5: Spin-coat a 20 mg / mL PCBM chlorobenzene solution directly onto the sulfur-containing interface modification layer at a speed of 2000 rpm / min for 30 s to obtain an electron transport layer with a thickness of 50 nm.

[0076] Step 6: Deposit a 120nm thick Ag film on the electron transport layer of step 5, with a cell area of ​​0.09cm². 2 The trans-inorganic CsPbI was obtained. 3-x Br x Perovskite solar cells.

[0077] Example 2

[0078] In step 4 of this embodiment, the concentration of the 2-mercapto-1-methylimidazole solution is replaced with 5 mg / mL, and the other steps are the same as in Example 1, to obtain trans-inorganic CsPbI. 3-x Br x Perovskite solar cells.

[0079] Example 3

[0080] In step 5 of this embodiment, the rotation speed of 2000 rpm / min is replaced with 4000 rpm / min, and the other steps are the same as in embodiment 1, to obtain trans-inorganic CsPbI. 3-x Br x Perovskite solar cells.

[0081] Example 4

[0082] In step 4 of this embodiment, 2-mercapto-1-methylimidazole in Example 1 is replaced with 1-[(1-methyl-1H-imidazol-2-yl)sulfonyl]-1H-benzotriazole, and the other steps are the same as in Example 1, to obtain trans-all-inorganic CsPbI 3-x Br x Perovskite solar cells.

[0083] Example 5

[0084] In step 4 of this embodiment, 2-mercapto-1-methylimidazole in Example 1 is replaced with 2-mercapto-1H-benzimidazole-5-carboxylic acid. The other steps are the same as in Example 1, yielding trans-all-inorganic CsPbI 3-x Br x Perovskite solar cells.

[0085] Example 6

[0086] In step 4 of this embodiment, 2-mercapto-1-methylimidazolium in Example 1 is replaced with 4-chloro-1-(dimethylaminosulfonyl)-5-(p-tolyl)imidazolium-2-carboxynitrile. The other steps are the same as in Example 1, yielding trans-all-inorganic CsPbI. 3- x Br x Perovskite solar cells.

[0087] Example 7

[0088] In step 4 of this embodiment, benzyl methyl sulfide is used to replace 2-mercapto-1-methylimidazolium in Example 1, and isopropanol is used to replace chlorobenzene in Example 1. The other steps are the same as in Example 1, resulting in trans-inorganic CsPbI 3-x Br x Perovskite solar cells.

[0089] Example 8

[0090] In step 4 of this embodiment, 2-mercapto-1-methylimidazolium in Example 1 is replaced with 4,4'-diaminodiphenyl disulfide, and isopropanol is replaced with chlorobenzene in Example 1. The other steps are the same as in Example 1, yielding trans-inorganic CsPbI 3-x Br x Perovskite solar cells.

[0091] Example 9

[0092] In step 4 of this embodiment, 2-mercapto-1-methylimidazolium in Example 1 is replaced with bis(trimethylsilylmethyl)sulfide, and isopropanol is replaced with chlorobenzene in Example 1. The other steps are the same as in Example 1, yielding trans-inorganic CsPbI 3-x Br x Perovskite solar cells.

[0093] Example 10

[0094] In step 4 of this embodiment, 2-mercapto-1-methylimidazolium in Example 1 is replaced with 2,2'-dithiopyridine, and isopropanol is replaced with chlorobenzene in Example 1. The other steps are the same as in Example 1, yielding trans-inorganic CsPbI 3-x Br x Perovskite solar cells.

[0095] Example 11

[0096] In step 4 of this embodiment, 2-mercapto-1-methylimidazolium thiocarbonate is replaced with O,O'-di-2-pyridinium ester in Example 1, and isopropanol is replaced with chlorobenzene in Example 1. The other steps are the same as in Example 1, yielding trans-inorganic CsPbI 3-x Br x Perovskite solar cells.

[0097] Example 12

[0098] In step 4 of this embodiment, 2-mercapto-1-methylimidazolium in Example 1 is replaced with 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol, and chlorobenzene in Example 1 is replaced with ethyl acetate. The other steps are the same as in Example 1, yielding trans-inorganic CsPbI. 3-x Br x Perovskite solar cells.

[0099] Example 13

[0100] In step 4 of this embodiment, 2-mercapto-1-methylimidazole in Example 1 is replaced with dithiophene, and the other steps are the same as in Example 1, to obtain trans-all-inorganic CsPbI 3-x Br x Perovskite solar cells.

[0101] Example 14

[0102] In step 4 of this embodiment, 2-mercapto-1-methylimidazolium in Example 1 is replaced with O-benzylhydroxylamine hydrochloride, and chlorobenzene in Example 1 is replaced with ethyl acetate. The other steps are the same as in Example 1, yielding trans-inorganic CsPbI 3-x Br x Perovskite solar cells.

[0103] Example 15

[0104] In step 4 of this embodiment, benzyl isothiourea hydrochloride is used to replace 2-mercapto-1-methylimidazolium in Example 1, and ethyl acetate is used to replace chlorobenzene in Example 1. The other steps are the same as in Example 1, yielding trans-all-inorganic CsPbI. 3-x Br x Perovskite solar cells.

[0105] Example 16

[0106] In step 4 of this example, benzyl chloromethyl sulfide was used to replace 2-mercapto-1-methylimidazole in Example 1, and isopropyl alcohol was used to replace chlorobenzene in Test Example 1. Other steps were the same as those in Example 1, and trans all-inorganic CsPbI 3-x Br x perovskite solar cells were obtained.

[0107] Example 17

[0108] In step 4 of this example, benzyl methyl disulfide was used to replace 2-mercapto-1-methylimidazole in Example 1, and isopropyl alcohol was used to replace chlorobenzene in Test Example 1. Other steps were the same as those in Example 1, and trans all-inorganic CsPbI 3-x Br x perovskite solar cells were obtained.

[0109] Example 18

[0110] In step 3 of this example, in step 3, FAI and PbI2 were dissolved in a mixed solution of dimethylformamide and dimethyl sulfoxide with a volume ratio of 9:1 and a molar ratio of 1:1, and stirred on a stirring table for more than 12 h to obtain a FAPbI3 perovskite precursor solution with a concentration of 1.0 mol / L to replace step 3 in Example 1.

[0111] Example 19

[0112] In step 3 of this example, in step 3, MAI and PbI2 were dissolved in a mixed solution of dimethylformamide and dimethyl sulfoxide with a volume ratio of 85:15 and a molar ratio of 1:1, and stirred on a stirring table for more than 12 h to obtain a MAPbI3 perovskite precursor solution with a concentration of 1.0 mol / L to replace step 3 in Example 1.

[0113] Example 20

[0114] In step 3 of this example, in step 3, FAI, CsI and PbI2 were dissolved in a mixed solution of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) with a volume ratio of 85:15 and a molar ratio of (1-y):y:1.0 (0<y<1), and stirred on a stirring table for more than 6 h to obtain a FA 1-y Cs y PbI3 perovskite precursor solution to replace step 3 in Example 1.

[0115] The perovskite solar cells prepared in the above Examples 1-20 and Comparative Example 1 were characterized respectively, and the results are shown in Figures 1-5 and Table 1.

[0116] Depend on Figure 1 The trans-all-inorganic CsPbI prepared in Comparative Example 1 and Examples 1, 6, and 14 3-x Br x As can be seen from the JV curve comparison chart of perovskite solar cells, the device efficiencies obtained by the preparation methods of Examples 1, 6, and 14 are all significantly higher than those of Comparative Example 1. This indicates that the perovskite solar cells modified with sulfur-containing interfaces have higher photoelectric performance.

[0117] Depend on Figure 2 The trans-inorganic CsPbI prepared in Comparative Example 1 and Example 1 3-x Br x As can be seen from the UPS spectrum of the perovskite thin film, compared with Comparative Example 1, the inorganic CsPbI film modified with a sulfur-containing interface in Example 1... 3-x Br x The energy levels of the perovskite thin film shift upwards as a whole, enabling energy level matching between the inorganic perovskite and the charge transport layer.

[0118] Depend on Figure 3 The trans-inorganic CsPbI prepared in Comparative Example 1 and Example 1 3-x Br x As can be seen from the PL spectrum of the perovskite thin film, compared with Comparative Example 1, the all-inorganic CsPbI film modified with a sulfur-containing interface in Example 1... 3-x Br x The perovskite film exhibits a stronger PL emission peak and a slight blue shift, indicating that nonradiative recombination on the film surface is suppressed and defects are reduced.

[0119] Depend on Figure 4 The trans-inorganic CsPbI prepared in Comparative Example 1 and Example 1 3-x Br x As can be seen from the TRPL spectrum of the perovskite thin film, compared with Comparative Example 1, the inorganic CsPbI film modified with a sulfur-containing interface in Example 1... 3-x Br x The average charge lifetime of the perovskite film increased from 66.1 nanoseconds to 125.9 nanoseconds, indicating that sulfur-containing interface modification can effectively suppress non-radiative charge recombination and passivate defects.

[0120] Depend on Figure 5 The trans-inorganic CsPbI prepared in Comparative Example 1 and Example 1 3-x Br xAs shown in the humidity stability comparison chart of perovskite solar cell devices, within a 1000-hour test period, the efficiency of the device in Comparative Example 1 decreased to 50%, while the efficiency of the device prepared in Example 1 decreased to 90% of its initial value. This is because sulfur-containing interface modification can passivate surface defects in the perovskite film, thereby reducing the defect density. Furthermore, sulfur-containing interface modification can reduce phase transitions or chemical degradation, thus extending the long-term stability of the device.

[0121] As shown in Table 1, compared with Comparative Example 1, the open-circuit voltage and efficiency of the devices obtained in Examples 1 to 17 are much higher than those in Comparative Example 1. This indicates that after modification with a sulfur-containing interface, non-radiative energy in the perovskite thin film is effectively suppressed, the energy levels are more matched, and finally, a high-efficiency and stable solar cell is obtained.

[0122] Table 1 Performance parameters of perovskite solar cells prepared in comparative examples and embodiments.

[0123]

Claims

1. A perovskite solar cell passivated with a sulfur-containing passivating agent, comprising, from bottom to top, a transparent conductive glass, a hole transport layer, a perovskite absorber layer, a sulfur-containing interface modification layer, an electron transport layer, and a metal electrode, stacked sequentially; or comprising, from bottom to top, a transparent conductive glass, an electron transport layer, a perovskite absorber layer, a sulfur-containing interface modification layer, a hole transport layer, and a metal electrode; characterized in that, The perovskite absorber layer is an APbX3 perovskite thin film with a perovskite structure, wherein A is any one or more of cesium ions, formamidinium ions, and methylamine ions, and X is any one or more of halide anions; the sulfur-containing interface modification layer is formed by depositing a sulfur-containing passivating agent onto the perovskite absorber layer by spin coating. The sulfur-containing passivating agent comprises any one of 1-[(1-methyl-1H-imidazol-2-yl)sulfonyl]-1H-benzotriazole, 2-mercapto-1H-benzimidazole-5-carboxylic acid, 4-chloro-1-(dimethylaminosulfonyl)-5-(p-tolyl)imidazol-2-carboxynitrile, benzyl methyl sulfide, 4,4'-diaminodiphenyl disulfide, bis(trimethylsilylmethyl) sulfide, dibenzyl disulfide, 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol, and benzyl methyl disulfide.

2. The perovskite solar cell passivated with a sulfur-containing passivating agent according to claim 1, characterized in that, The method for preparing the sulfur-containing interface modification layer is as follows: a sulfur-containing passivating agent is added to a mixture of any one or more of chlorobenzene, isopropanol, toluene, ethyl acetate, etc., and heated and stirred until dissolved to obtain a passivating agent solution; the passivating agent solution is spin-coated onto the perovskite absorber layer, and then placed in a low vacuum environment to stand. After standing, a passivation layer, i.e., a sulfur-containing interface modification layer, is formed on the perovskite absorber layer.

3. The perovskite solar cell passivated with a sulfur-containing passivating agent according to claim 2, characterized in that, The concentration of sulfur-containing passivating agent in the passivating agent solution is 1–20 mg / mL, the spin coating speed is 2000–6000 rpm, the time is 20–80 s, and the standing time is 10–60 min.

4. The perovskite solar cell passivated with a sulfur-containing passivating agent according to claim 1, characterized in that, The hole transport layer has a thickness of 10–60 nm and is formed by spin-coating a hole transport layer solution with a concentration of 1–30 mg / mL onto a transparent conductive glass substrate followed by annealing. The hole transport layer material is any one of NiO, WO3, MoO3, poly(9-vinylcarbazole), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], a polymer of 3-hexylthiophene, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, CuSCN, N′-di(phenyl)benzidine, or 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene. The spin-coating speed is 1000–5000 rpm for 40 s, and the annealing temperature is 100–200 ℃ for 10–40 min.

5. The perovskite solar cell passivated with a sulfur-containing passivating agent according to claim 1, characterized in that, The thickness of the perovskite absorber layer is 300–800 nm, and it is formed by spin-coating a perovskite precursor solution onto the hole transport layer followed by annealing. The perovskite precursor solution uses a mixture of dimethylformamide and dimethyl sulfoxide as a solvent, and the concentration of the perovskite precursor solution is 0.5–1.5 mol / L. The spin-coating is performed in two stages: the first stage has a rotation speed of 500–1500 rpm and a time of 5–30 s, and the second stage has a rotation speed of 2000–5000 rpm and a time of 30–50 s. The annealing temperature is 100–210 °C and the time is 5–40 min.

6. The perovskite solar cell passivated with a sulfur-containing passivating agent according to claim 1, characterized in that, The electron transport layer has a thickness of 20–50 nm and is obtained by directly spin-coating an electron transport layer solution with a concentration of 1–20 mg / mL onto a sulfur-containing interface modification layer; wherein the electron transport layer material is TiO2, SnO2, methyl (6,6)-phenyl-C61-butyrate, C 60 The coating is prepared by selecting any one of Nb2O3, 1,3,5-tris-(N-phenyl-imidazolium-2-yl)benzene, and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; the spin coating is performed at a speed of 2000–4000 rpm for 20–40 s, and the annealing temperature is 60–210 ℃ for 10–30 min.

7. The perovskite solar cell passivated with a sulfur-containing passivating agent according to claim 1, characterized in that, The metal electrode is made of any one of Au, Ag, or Cu, and is deposited on the electron transport layer with a deposition thickness of 80–100 nm.

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