Perovskite precursor solution and perovskite solar cell and method of manufacturing the same

Abstract

The application discloses a perovskite precursor solution and a perovskite solar cell and a preparation method thereof, the perovskite precursor solution comprises lead iodide, methyl amine iodide, an organic solvent and 1-benzyl-3-hydroxyl pyridine chloride; the perovskite solar cell comprises a perovskite layer, and the perovskite layer is obtained by spin coating the perovskite precursor solution; and the perovskite precursor solution is prepared by adding 1-benzyl-3-hydroxyl pyridine chloride (1B3HPC) in the preparation process of the perovskite precursor solution, so that the thin film grains in the perovskite layer are dense and uniform, the grain size is large, the number of grain boundaries is reduced, the stability of the crystal structure in the perovskite layer is improved, and the photoelectric performance and stability of the perovskite solar cell device are improved.

Description

Technical Field

[0001] This invention relates to the field of thin-film solar cell technology, specifically to a perovskite precursor solution, a perovskite solar cell, and a method for preparing the same. Background Technology

[0002] With population growth, global energy demand is increasing. Therefore, developing new energy sources is urgent. Hydropower and wind power require specific natural environmental conditions, nuclear power poses safety risks, while solar energy offers advantages such as long-term stability, high energy output, low cost, and environmental friendliness, making it a current hot topic in new energy research. Solar energy is inexhaustible and pollution-free. There are three ways to directly utilize solar energy: converting light energy into electrical energy, heat energy, and chemical energy, with power generation showing the greatest potential. Since the discovery of the photovoltaic effect in 1839, research on solar cells has begun. In 1957, the first monocrystalline silicon solar cell was manufactured. Today, solar cells have undergone three generations of evolution, such as... Figure 1 As shown, the first generation is silicon-based solar cells, which are also the longest-developed and most technologically mature generation of cells. Second-generation solar cells are manufactured using various thin-film substrates. Compared to the first generation, they require significantly less material and are easier to mass-produce; representative examples are copper indium gallium selenide (CIGS) and gallium arsenide (GaAs) cells. CIGS has excellent photoelectric performance and does not exhibit light-induced degradation, but its application is severely limited due to its low reserves and rarity. Gallium arsenide has a theoretical PCE of 28%, but its commercialization is difficult due to its epitaxial manufacturing technology, the high cost caused by the scarcity of gallium, and the presence of toxic arsenic.

[0003] Therefore, further development of novel photovoltaic cells is needed to meet the demands for low cost and high efficiency. Perovskite materials are a class of materials with an ABX3 molecular structure, composed of cations (A), divalent metal cations (B), and halide ions (X). Perovskite solar cells utilize an organometal halide perovskite layer as a light-absorbing material, directly converting light energy into electrical energy through the photoelectric effect, belonging to the third generation of solar cells. Their working principle is that when light shines on the device, electrons in the valence band of the perovskite layer absorb light energy and jump to the conduction band, thus forming photogenerated electron-hole pairs. Electrons flow to the electron transport layer, and holes flow to the hole transport layer, forming a circuit and generating current. After ten years of development, the PCE of PSCs has rapidly increased from an initial 3.9% to over 25%.

[0004] In an ideal crystal structure, each atom has its own corresponding position. However, in actual crystal structures, defects are introduced due to the crystal growth and post-processing. These defects introduce transition levels into the band gap. When these transition levels are close to the valence or conduction bands, shallow level defects are formed. Carriers trapped in shallow level traps are easily released, so shallow level defects have little impact on carrier recombination. When the transition level is located in the middle third of the band gap, deep level defects are formed. These defects firmly trap electrons or holes, forming recombination centers. This is detrimental to carrier extraction in perovskites and severely affects conductivity, carrier mobility, and carrier lifetime.

[0005] The perovskite layer in perovskite solar cells fabricated using existing technologies faces two key problems. First, the original perovskite film has a small grain size and contains numerous grain boundaries, which are defect-rich regions that hinder carrier transport and affect device lifetime and current density. Second, the perovskite layer contains numerous defects, primarily originating from low-coordinated Pb at the perovskite layer surface. 2+ Halogen ions and vacancies. Summary of the Invention

[0006] This invention addresses the technical problem of small grain size and numerous defects in the original thin film of perovskite layer in existing perovskite solar cells, which hinders carrier transport in the perovskite and seriously affects the lifespan and photoelectric performance of perovskite solar cells. The purpose is to provide a perovskite precursor solution, a perovskite solar cell, and a method for preparing the same, which can increase the grain size of the perovskite layer and improve the lifespan and photoelectric performance of the cell.

[0007] One objective of this invention is to provide a perovskite precursor solution comprising lead iodide, methylamine iodide, and an organic solvent, wherein the perovskite precursor solution further comprises 1-benzyl-3-hydroxypyridine chloride.

[0008] Preferably, the concentration of lead iodide (PbI2) is 1–1.5 mol / L, more preferably 1 mol / L; the concentration of methylamine iodide (MAI) is 1–1.5 mol / L, more preferably 1 mol / L; and the concentration of 1-benzyl-3-hydroxypyridine chloride (1B3HPC) is 0.03–0.05 mol / L, more preferably 0.03 mol / L.

[0009] The organic solvent is a mixed solution of dimethylformamide and dimethyl sulfoxide, wherein the volume ratio of dimethylformamide to dimethyl sulfoxide is 5:1 to 9:1.

[0010] Another object of the present invention is to provide a perovskite solar cell, the perovskite solar cell comprising a perovskite layer, the perovskite layer being obtained by spin-coating the perovskite precursor solution.

[0011] Preferably, the perovskite solar cell comprises, from bottom to top: a glass substrate, an electron transport layer, and a perovskite layer.

[0012] Preferably, the perovskite solar cell further comprises, in sequence, a hole transport layer and a metal electrode on the perovskite layer.

[0013] Preferably, the perovskite solar cell further includes a carbon electrode on the perovskite layer.

[0014] Another object of the present invention is to provide a method for fabricating a perovskite solar cell, the method comprising the following steps:

[0015] S1. Clean the glass substrate;

[0016] S2. The electron transport layer is prepared on the glass substrate;

[0017] S3. Prepare the perovskite precursor solution;

[0018] S4. Spin-coat the perovskite precursor solution onto the electron transport layer, and then anneal it to obtain the perovskite layer.

[0019] Preferably, the method further includes the following steps:

[0020] S5a. Spin-coating the hole transport layer onto the perovskite layer obtained in step S4 with a solution, and then oxidizing it fully to obtain the hole transport layer.

[0021] S6. Deposit the metal electrode onto the hole transport layer.

[0022] Preferably, the method further includes the following steps:

[0023] S5b: Carbon paste is coated onto the perovskite layer obtained in step S4, and the carbon electrode is obtained after annealing.

[0024] Preferably, the preparation of the perovskite precursor solution in step S3 refers to: dissolving 1-1.5 mmol lead iodide and 1-1.5 mmol methyl iodide in 1 mL of organic solvent, and then adding 0.03 mmol-0.05 mmol 1-benzyl-3-hydroxypyridine chloride and stirring thoroughly to obtain the perovskite precursor solution;

[0025] The organic solvent is a mixed solution of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), wherein the volume ratio of dimethylformamide to dimethyl sulfoxide is 5:1 to 9:1.

[0026] The term "thorough stirring" refers to stirring at room temperature for 5 to 8 hours.

[0027] Step S4, spin-coating the perovskite precursor solution onto the electron transport layer, refers to: first spin-coating the perovskite precursor solution at a low speed of 1000-1800 r / min onto a 1×1 cm layer. 2 After 10–15 s on the electron transport layer, the perovskite precursor solution is spin-coated at a high speed of 3500–5000 r / min onto a 1×1 cm plate. 2 25–35 s on the electron transport layer;

[0028] The spin-coating amount of the perovskite precursor solution is 50–70 μL / cm. 2 ;

[0029] During the high-speed spin coating process of 6–8 s, the anti-solvent chlorobenzene is added dropwise, and the ratio of the amount of anti-solvent chlorobenzene added to the amount of spin coating solution of the perovskite precursor solution is 2:3.

[0030] The annealing process refers to annealing at 100–120°C for 10–20 minutes.

[0031] Preferably, the cleaning of the glass substrate in step S1 refers to ultrasonically cleaning the glass substrate in ethanol, detergent, ultrapure water, isopropanol and ethanol in sequence for 10 to 30 minutes, and then drying the cleaned glass substrate with nitrogen gas; the glass substrate is selected from indium tin oxide and FTO.

[0032] Preferably, the electron transport layer in step S2 is selected from tin oxide, titanium dioxide, and zinc oxide; and the preparation method of the electron transport layer on the glass substrate is selected from solvent bath method, spin coating method, blade coating method, screen printing, spraying, slot coating and vapor deposition method.

[0033] Preferably, the hole transport layer solution in step S5a is a 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro) solution;

[0034] The method for preparing the hole transport layer solution includes: dissolving 500-600 mg of lithium bis(trifluoromethane) yellow imide in 1-3 mL of acetonitrile (ACN) to obtain a lithium bis(trifluoromethane) yellow imide solution; then adding 16-20 μL of the lithium bis(trifluoromethane) yellow imide solution, 20-30 μL of tetra-tert-butylpyridine, and 1-3 mL of chlorobenzene (CB) to 70-80 mg of 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene, and fully dissolving to obtain the hole transport layer solution;

[0035] The hole transport layer is spin-coated onto the perovskite layer obtained in step S4 at a spin-coating speed of 3000-5000 r / min and a spin-coating time of 20-30 s.

[0036] The oxidation time for complete oxidation is 10–25 hours.

[0037] Preferably, the annealing treatment in step S5b refers to annealing at 100–120°C for 20–40 min.

[0038] Preferably, the metal electrode in step S6 is selected from silver, gold, copper, and aluminum;

[0039] The thickness of the metal electrode deposited on the hole transport layer obtained in step S5a is 60-200 nm.

[0040] The positive and progressive effects of this invention are as follows:

[0041] This invention effectively solves two problems existing in the perovskite layer of perovskite solar cells prepared by prior art, by adding the additive 1-benzyl-3-hydroxypyridine chloride (1B3HPC) during the preparation of the perovskite precursor solution. The Cl in 1B3HPC... - It can coordinate with PbI2, increasing solubility. The hydroxyl groups can form hydrogen bonds with MA and I, delaying the nucleation and crystallization of perovskite. This results in denser and more uniform grains in the perovskite layer after annealing, with larger grain sizes and fewer grain boundaries, thus improving the stability of the crystal structure in the perovskite layer. Simultaneously, the pyridine functional group in 1B3HPC acts as a Lewis base, passivating poorly coordinated Pb on the surface that function as Lewis acids. 2+ The formation of Lewis adducts reduces nonradiative recombination and increases carrier lifetime, thereby improving the photoelectric performance and stability of perovskite solar cells. Furthermore, the hydrogen bonds formed between the hydroxyl groups in 1B3HPC and organic cations suppress ion migration, further enhancing the stability of perovskite solar cells. Attached Figure Description

[0042] Figure 1This is a schematic diagram of the perovskite solar cells prepared in Examples 1 and 3 of the present invention. Detailed Implementation

[0043] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0044] The perovskite solar cell passivated by the additives of the present invention includes two structures: the first structure consists of a glass substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode from bottom to top; the second structure consists of a glass substrate, an electron transport layer, a perovskite layer, and a carbon electrode from bottom to top.

[0045] Examples 1-8 used perovskite precursor solutions containing 1B3HPC to prepare perovskite solar cells. Examples 1-3 are described below, and the preparation process of Examples 4-8 is consistent with that of Examples 1-3. The experimental parameters are shown in Table 2.

[0046] Example 1: A perovskite solar cell was fabricated with the following structure: ITO, tin dioxide, perovskite layer, hole transport layer, and silver electrode. The glass substrate used was indium tin oxide (ITO). The specific structure is as follows: Figure 1 As shown in Figure 1a, the specific steps are as follows:

[0047] Step S1: Clean the glass substrate. (The text abruptly ends here, likely due to an incomplete sentence or a formatting error.) 2 Indium tin oxide (ITO) glass substrates were ultrasonically cleaned for 15 minutes in sequence by immersion in 200 mL of ethanol, detergent, ultrapure water, isopropanol and ethanol, and then dried with nitrogen.

[0048] Step S2: Prepare the electron transport layer on the glass substrate. Mix 200 μL of 15 wt% tin dioxide (SnO2) aqueous dispersion with 1 mL of ultrapure water, and stir thoroughly to obtain a tin oxide solution. Then, take 60 μL of the tin oxide solution and coat it onto a 1×1 cm substrate after UV ozone treatment for 15 min. 2 A tin dioxide electron transport layer was obtained by annealing at 180°C for 30 minutes on an ITO glass substrate.

[0049] Step S3: Prepare the perovskite precursor solution. Weigh 1 mmol of lead iodide (PbI2) and 1 mmol of methylamine iodide (MAI) and dissolve them in a mixed solvent of 100 μL of dimethyl sulfoxide (DMSO) and 900 μL of dimethylformamide (DMF) (total volume of mixed solvent is 1 mL). The volume ratio of dimethyl sulfoxide (DMSO) to dimethylformamide (DMF) in the mixed solvent is 9:1. Add 0.03 mmol of 1B3HPC and stir thoroughly to form the perovskite precursor solution. Stir for 8 h.

[0050] Step S4: Spin-coat the perovskite precursor solution onto the electron transport layer, and anneal the resulting perovskite layer. Clean the glass substrate with the electron transport layer deposited in step S2 in an SC-UV-I type ultraviolet ozone cleaner for 15 minutes, then anneal it at a 1×1 cm depth. 2 The perovskite layer was prepared by spin-coating 60 μL of the perovskite precursor solution onto the surface of the electron transport layer. The spin-coating consisted of two steps: first, a low-speed spin-coating at 1000 r / min for 10 s; and second, a high-speed spin-coating at 4000 r / min for 30 s. During the high-speed spin-coating, the perovskite layer was formed within 6–7 s at a depth of 1 × 1 cm. 2 150 μL of the antisolvent chlorobenzene was dropped onto the electron transport layer, and then annealed at 100 °C for 10 min to obtain a 1 × 1 cm⁻¹ electron transport layer. 2 The perovskite layer.

[0051] Step S5a: Spin-coat the hole transport layer solution onto the perovskite layer obtained in step S4, and obtain the hole transport layer after complete oxidation. The hole transport layer solution is a 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene solution, prepared as follows: Dissolve 520 mg of lithium bis(trifluoromethane)xanimide in 1 mL of acetonitrile to obtain a lithium bis(trifluoromethane)xanimide solution. Then, add 17.5 μL of lithium bis(trifluoromethane)xanimide solution, 28.8 μL of tetra-tert-butylpyridine, and 1 mL of chlorobenzene to 72.3 mg of 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene, and dissolve completely to obtain the hole transport layer solution. Then, spin-coat 60 μL of the hole transport layer solution onto the 1×1 cm layer obtained in step S4. 2 On the perovskite layer, the spin coating speed is 3000 r / min and the spin coating time is 30 s. After being fully oxidized for 20 h, the 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro) hole transport layer in the perovskite solar cell of Example 1 is obtained.

[0052] Step S6: Deposit the metal electrode onto the hole transport layer. The silver electrode is deposited using a ZHDS400 evaporation machine. Silver metal is evaporated in a high vacuum to deposit onto the hole transport layer in step S5a, resulting in the silver electrode in the perovskite solar cell of Example 1. The thickness of the silver electrode is 200 nm.

[0053] Example 2: A perovskite solar cell was fabricated with the following battery structure in sequence: FTO, dense titanium oxide layer, mesoporous titanium oxide layer, perovskite layer, hole transport layer and silver electrode. The glass substrate used was fluorine-doped tin oxide (FTO substrate).

[0054] Step S1: Clean the glass substrate. (The text abruptly ends here, likely due to an incomplete sentence or a formatting error.) 2 The FTO glass substrate was ultrasonically cleaned for 15 minutes in 200 mL of ethanol, detergent, ultrapure water, isopropanol and ethanol in sequence, and then dried with nitrogen.

[0055] Step S2: Prepare the electron transport layer on the glass substrate. A dense titanium dioxide layer is prepared using a hydrolysis method: 70 μL of 2 mol / L hydrochloric acid aqueous solution and 750 mL of isopropyl titanate are added to 10 mL of anhydrous ethanol, and the mixture is stirred thoroughly to obtain a titanium dioxide precursor solution. The FTO substrate, after being treated with UV ozone for 15 min, is placed on a KW-4 spin coater, and 60 μL of the titanium dioxide precursor solution is added dropwise. The substrate is then spin-coated at 4000 r / min for 30 s, annealed at 150 °C for 15 min, and then transferred to an SX2-12-10 muffle furnace for annealing at 500 °C for 1 h. Then, 2.845g of P25 titanium dioxide, 1.425g of ethyl cellulose, 11.538g of terpineol and 63.222g of ethanol were weighed and ball-milled for 24h to obtain titanium dioxide slurry. The slurry was coated onto the surface of dense titanium dioxide at 3000r / min and annealed at 500℃ for 1h to form mesoporous titanium dioxide.

[0056] Step S3: Prepare the perovskite precursor solution. Weigh 1 mmol of lead iodide (PbI2) and 1 mmol of methylamine iodide and dissolve them in a mixed solvent of 100 μL of dimethyl sulfoxide (DMSO) and 900 μL of dimethylformamide (DMF). Add 0.03 mmol of 1B3HPC and stir thoroughly to form the perovskite precursor solution for 8 hours.

[0057] Step S4: Spin-coat the perovskite precursor solution onto the electron transport layer, and anneal the resulting perovskite layer. Clean the glass substrate with the electron transport layer deposited in step S2 in an SC-UV-I type ultraviolet ozone cleaner for 15 minutes, then anneal it at a 1×1 cm depth. 2The electron transport layer, i.e., the mesoporous titanium dioxide layer, obtained in step S2, is spin-coated with 60 μL of perovskite precursor solution to prepare a perovskite layer. The spin-coating is divided into two steps: first, low-speed spin-coating at 1000 r / min for 10 s; second, high-speed spin-coating at 4000 r / min for 30 s. During the high-speed spin-coating, the perovskite layer is formed within 6–7 s at a depth of 1 × 1 cm. 2 150 μL of the antisolvent chlorobenzene was dropped onto the mesoporous titanium dioxide layer, and then annealed at 100 °C for 10 min to obtain a 1×1 cm⁻¹ layer. 2 The perovskite layer.

[0058] Step S5a: Spin-coat the hole transport layer solution onto the perovskite layer obtained in step S4, and obtain the hole transport layer after complete oxidation. The hole transport layer solution is a 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene solution, prepared as follows: Dissolve 520 mg of lithium bis(trifluoromethane)flavinimide in 1 mL of acetonitrile, then add 17.5 μL of lithium bis(trifluoromethane)flavinimide solution, 28.8 μL of tetra-tert-butylpyridine, and 1 mL of chlorobenzene to 72.3 mg of 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene, and dissolve completely to obtain the hole transport layer solution. Then, spin-coat 60 μL of the hole transport layer solution onto the 1×1 cm layer obtained in step S4. 2 On the perovskite layer, the spin coating speed is 3000 r / min and the spin coating time is 30 s. After full oxidation for 20 h, the hole transport layer in the perovskite solar cell of Example 2 is obtained.

[0059] Step S6: Evaporate the metal electrode onto the hole transport layer. The silver electrode is deposited onto the hole transport layer in step S5a by evaporating silver metal in a high vacuum using a ZHDS400 evaporation machine, resulting in the silver electrode of the perovskite solar cell in Example 2. The thickness of the silver electrode is 200 nm.

[0060] Example 3: Fabrication of a perovskite solar cell with a battery structure consisting of ITO, tin dioxide, a perovskite layer, and a carbon electrode, wherein the glass substrate used is indium tin oxide (ITO), as detailed below. Figure 1 As shown in Figure 1b, the specific preparation steps are as follows.

[0061] Step S1: Clean the glass substrate. (The text abruptly ends here, likely due to an incomplete sentence or a formatting error.) 2 Indium tin oxide (ITO) glass substrates were ultrasonically cleaned for 15 minutes in sequence by immersion in 200 mL of ethanol, detergent, ultrapure water, isopropanol and ethanol, and then dried with nitrogen.

[0062] Step S2: Prepare the electron transport layer on the glass substrate. Mix 200 μL of 15 wt% tin dioxide (SnO2) aqueous dispersion with 1 mL of ultrapure water, and stir thoroughly to obtain a tin oxide solution. Then, take 60 μL of the tin oxide solution and coat it onto a 1×1 cm substrate after UV ozone treatment for 15 min. 2 A tin dioxide electron transport layer was obtained by annealing at 180°C for 30 minutes on an ITO glass substrate.

[0063] Step S3: Prepare the perovskite precursor solution. Weigh 1 mmol of lead iodide (PbI2) and 1 mmol of methylamine iodide and dissolve them in a mixed solvent of 100 μL of dimethyl sulfoxide (DMSO) and 900 μL of dimethylformamide (DMF). Add 0.03 mmol of 1B3HPC and stir thoroughly to form the perovskite precursor solution for 8 hours.

[0064] Step S4: Spin-coat the perovskite precursor solution onto the electron transport layer, and anneal the solution to obtain the perovskite layer. Clean the glass substrate with the electron transport layer deposited in step S2 in an SC-UV-I type ultraviolet ozone cleaner for 15 minutes, then spin-coat the substrate onto a 1×1 cm plate. 2 The perovskite layer was prepared by spin-coating 60 μL of perovskite precursor solution onto the surface of the electron transport layer. The spin-coating consisted of two steps: first, a low-speed spin-coating at 1000 r / min for 10 s; and second, a high-speed spin-coating at 4000 r / min for 30 s. During the high-speed spin-coating, the perovskite layer was formed within 6–7 s at a depth of 1 × 1 cm. 2 150 μL of the antisolvent chlorobenzene was dropped onto the electron transport layer, and then annealed at 100 °C for 10 min to obtain a 1 × 1 cm⁻¹ electron transport layer. 2 Perovskite layer.

[0065] S5b: Carbon paste is coated onto the perovskite layer obtained in step S4, and the carbon electrode is obtained after annealing. A small amount of carbon paste is directly coated onto the surface of the perovskite layer obtained in step S4 using a glass slide to completely cover the entire surface of the perovskite layer. The carbon electrode in the perovskite solar cell of Example 3 is obtained after annealing at 100°C for 30 minutes.

[0066] Comparative Examples 1-3: Perovskite solar cells were fabricated using perovskite precursor solutions without the addition of 1B3HPC.

[0067] The fabrication steps of the perovskite solar cells in Comparative Examples 1-3 are consistent with those in Examples 1-3, and the experimental parameters of Comparative Examples 1-3 are shown in Table 1 below:

[0068] Table 1. Experimental parameters for the fabrication of perovskite solar cells in Examples 1-3 and Comparative Examples 1-3.

[0069]

[0070]

[0071]

[0072] Table 2. Experimental parameters for the fabrication of perovskite solar cells in Examples 4-8.

[0073]

[0074]

[0075]

[0076] Performance Effect Examples

[0077] The photoelectric performance of Examples 1-3 and Comparative Examples 1-3 was tested using an SS-X160R solar simulator and KA6000 testing software. The test results are shown in Table 3 below:

[0078] Table 3. Photoelectric performance test results of Examples 1-3 and Comparative Examples 1-3

[0079] Open circuit voltage (V) <![CDATA[Short-circuit current density (mA cm -2 )]]> FF PCE (%) Example 1 1.12 24.72 72.94 22.36 Example 2 1.15 22.46 71.82 20.54 Example 3 1.09 19.56 65.42 15.65 Comparative Example 1 1.11 23.77 70.09 20.47 Comparative Example 2 1.08 22.96 69.87 19.18 Comparative Example 3 1.05 19.32 62.47 14.03

[0080] Table 4. Stability test results of perovskite solar cells after 1000 hours of irradiation by an SS-X160R solar simulator at room temperature and ambient air.

[0081]

[0082] As shown in Table 3, the performance comparison between Examples 1-3 and Comparative Examples 1-3 demonstrates that the perovskite solar cells prepared using the perovskite precursor solution containing 1B3HPC provided by this invention exhibit significantly superior photoelectric performance compared to perovskite solar cells prepared using existing technologies. Furthermore, Table 4 shows that the perovskite solar cells of this invention demonstrate better short-circuit current density and stability compared to Examples 1-3 and Comparative Examples 1-3, indicating less non-radiative recombination in the perovskite solar cells prepared by this invention. In other words, compared to perovskite solar cells prepared using existing technologies, the perovskite thin film in the perovskite solar cells prepared by this invention exhibits significantly fewer defects and a larger perovskite thin film grain size, thereby promoting carrier transport and improving cell stability. In other words, the addition of 1-benzyl-3-hydroxypyridine chloride to the perovskite precursor solution of this invention can increase grain size and improve the stability of the perovskite solar cell. In summary, this invention solves the problems of small initial thin film grain size and numerous defects in perovskite layers prepared using existing technologies.

[0083] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A perovskite precursor solution comprising lead iodide, methylamine iodide, and an organic solvent, characterized in that... It also includes 1-benzyl-3-hydroxypyridine chloride.

2. The perovskite precursor solution as described in claim 1, characterized in that, The concentration of lead iodide is 1~1.5 mol / L, the concentration of methylamine iodide is 1~1.5 mol / L, and the concentration of 1-benzyl-3-hydroxypyridine chloride is 0.03~0.05 mol / L; The organic solvent is a mixed solution of dimethylformamide and dimethyl sulfoxide, wherein the volume ratio of dimethylformamide to dimethyl sulfoxide is 5:1 to 9:

1.

3. A perovskite solar cell, said perovskite solar cell comprising a perovskite layer, characterized in that... The perovskite layer is obtained by spin-coating the perovskite precursor solution as described in claim 1 or 2.

4. The perovskite solar cell as described in claim 3, characterized in that... The perovskite solar cell comprises, from bottom to top: a glass substrate, an electron transport layer, and a perovskite layer.

5. The perovskite solar cell as described in claim 4, characterized in that... The perovskite solar cell further comprises, in sequence, a hole transport layer and a metal electrode on top of the perovskite layer.

6. The perovskite solar cell as described in claim 4, characterized in that... The perovskite solar cell further includes a carbon electrode on top of the perovskite layer.

7. A method for preparing the perovskite solar cell according to claim 4, characterized in that, The method includes the following steps: S1. Clean the glass substrate; S2. The electron transport layer is prepared on the glass substrate; S3. Prepare the perovskite precursor solution; S4. Spin-coat the perovskite precursor solution onto the electron transport layer, and then anneal it to obtain the perovskite layer.

8. The method as described in claim 7, characterized in that, The method further includes the following steps: S5a. Spin-coating the hole transport layer onto the perovskite layer obtained in step S4 with a solution, and then oxidizing it fully to obtain the hole transport layer. S6. Deposit a metal electrode onto the hole transport layer.

9. The method as described in claim 7, characterized in that, The method further includes the following steps: S5b: Carbon paste is coated onto the perovskite layer obtained in step S4, and the carbon electrode is obtained after annealing.

10. The method as described in claim 7, characterized in that, The preparation of the perovskite precursor solution in step S3 refers to: dissolving 1~1.5 mmol lead iodide and 1~1.5 mmol methyl iodide in 1 mL of organic solvent, and then adding 0.03~0.05 mmol 1-benzyl-3-hydroxypyridine chloride and stirring thoroughly to obtain the perovskite precursor solution; The organic solvent is a mixed solution of dimethylformamide and dimethyl sulfoxide, wherein the volume ratio of dimethylformamide to dimethyl sulfoxide is 5:1 to 9:

1. The term "thorough stirring" refers to stirring at room temperature for 5-8 hours. Step S4, spin-coating the perovskite precursor solution onto the electron transport layer, refers to: first spin-coating the perovskite precursor solution at a low speed of 1000~1800 r / min onto a 1×1 cm layer. 2 After 10-15 seconds on the electron transport layer, the perovskite precursor solution is spin-coated at a high speed of 3500-5000 r / min onto a 1×1 cm plate. 2 25-35s on the electron transport layer; The spin-coating amount of the perovskite precursor solution is 50~70 μL / cm. 2 ; During high-speed spin coating for 6-8 seconds, the anti-solvent chlorobenzene is added dropwise at a rate of 150-180 μL / cm. 2 ; The annealing process refers to annealing at 100~120℃ for 10~20 minutes.

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