A three-dimensional two-dimensional core-shell self-encapsulation structure anti-perovskite solar cell and a preparation method thereof

Abstract

This invention belongs to the technical field of solar cells and discloses a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell and its preparation method. The method involves preparing an inverted planar heterojunction perovskite solar cell using NiO nanocrystals with a particle size of 3-5 nm and SnO2 nanorods with a particle size of 2-4 nm and an aspect ratio of 3-5, respectively, forming a hole transport layer (15-25 nm) and an electron transport layer (15-30 nm). A pyridylamine derivative hydrohalate is attached as a ligand to the surface of the NiO nanocrystals and SnO2 nanorods and added to the PbI2 layer. During the two-step preparation of the three-dimensional perovskite light-absorbing layer (500-800 nm) of formamidine triiodide(II)ate (FAPbI3), two-dimensional perovskites are simultaneously generated at the FAPbI3 / hole transport layer interface, the FAPbI3 / electron transport layer interface, and the grain boundaries within the FAPbI3 layer, thus forming a three-dimensional two-dimensional core-shell self-encapsulated perovskite light-absorbing layer. Finally, an aluminum-doped zinc oxide (AZO) top electrode was sputtered onto the electron transport layer to obtain a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and in particular to a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell and its preparation method. Background Technology

[0002] Perovskite solar cells, with their advantages such as high light absorption coefficient, high carrier mobility, tunable bandgap, and low-temperature solution processing, have become the core development direction of next-generation high-efficiency and low-cost photovoltaic technology, and their photoelectric conversion efficiency has rapidly exceeded 27%, demonstrating enormous potential. However, problems such as the difficulty in balancing efficiency and stability, interface defects and ion migration, and insufficient environmental tolerance remain key bottlenecks restricting their industrialization.

[0003] Three-dimensional perovskites, with their typical ABX3 cubic / tetragonal crystal structure, possess outstanding advantages such as long carrier diffusion length, excellent charge transport performance, strong light absorption, and high photoelectric conversion efficiency, making them a core material system for realizing high-efficiency devices. However, their crystal structure has inherent defects such as weak ionic bonding, numerous grain boundary defects, and sensitivity to water, oxygen, temperature, and ultraviolet light. Under conditions such as damp heat and light cycling, they are prone to phase transitions, decomposition, and ion migration, leading to rapid performance degradation and poor long-term operational stability, making it difficult to meet the requirements of outdoor applications.

[0004] Two-dimensional perovskites, by introducing large-sized organic / inorganic spacer cations, form layered quantum well-like structures. These structures exhibit superior hydrophobicity, structural rigidity, and environmental stability compared to three-dimensional perovskites, effectively suppressing water and oxygen intrusion and ion migration. They are widely used for surface / grain boundary passivation of three-dimensional perovskites. However, two-dimensional perovskites suffer from drawbacks such as high interlayer tunneling barriers, low carrier mobility, wider band gaps, and weak light absorption. Using them alone significantly reduces device short-circuit current and fill factor, making it difficult to achieve high-efficiency output. Furthermore, conventional three-dimensional and two-dimensional heterojunctions are mostly surface-covered or simply mixed, resulting in weak interfacial bonding, significant phase separation, and a tendency to generate interfacial recombination centers. Long-term operation can lead to interface degradation and stability failure.

[0005] Current mainstream three-dimensional and two-dimensional composite perovskite light-absorbing layers generally suffer from the following technical pain points: the two-dimensional layer only covers the surface and cannot achieve full-dimensional encapsulation of the three-dimensional grains, allowing water and oxygen to still penetrate along the grain boundaries; the interface matching between the two-dimensional and three-dimensional phases is poor, and the charge transport impedance is high, making it difficult to achieve a balance between efficiency and stability; there is no self-encapsulation effect, relying on external encapsulation, resulting in complex processes, high costs, and limited reliability; grain boundary defects and ion migration have not been fundamentally suppressed, and the stability under humid heat and light exposure is still not up to standard.

[0006] To overcome the aforementioned bottlenecks, it is urgent to construct a novel perovskite structure that combines high photoelectric efficiency with high environmental stability.

[0007] In view of this, the inventor of this case conducted in-depth research, which led to the creation of this case. Summary of the Invention

[0008] The purpose of this invention is to provide a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell, which can generate a two-dimensional perovskite shell at the grain boundaries within the three-dimensional perovskite layer and at the interface with the hole and electron transport layer, thereby achieving "high-efficiency power generation in the core and self-encapsulation and protection in the shell", ensuring high photoelectric conversion efficiency and long-term stability of the solar cell.

[0009] The present invention also aims to provide a method for preparing the above-mentioned three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell.

[0010] To achieve the above objectives, the technical solution of the present invention is as follows: A three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell includes a conductive glass conductive layer, a hole transport layer, a FAPbI3 three-dimensional two-dimensional core-shell self-encapsulated perovskite light absorption layer, an electron transport layer, and an AZO electrode layer arranged sequentially, wherein the hole transport layer is stacked on the conductive glass conductive layer. A PbI2 layer for two-step preparation of FAPbI3 layer is formed on the hole transport layer. The PbI2 layer is an intermediate for generating FAPbI3 layer. The PbI2 layer is prepared by coating the hole transport layer with PbI2 solution. The hole transport layer, the PbI2 layer, and the electron transport layer all introduce organic macrocations for generating two-dimensional titanium ore, and the source of the organic macrocations is a pyridylamine derivative hydrohalate; the electron transport layer is formed on the FAPbI3 layer, and the AZO electrode layer is sputtered on the electron transport layer; During the preparation of the FAPbI3 three-dimensional two-dimensional core-shell self-encapsulated perovskite light absorption layer, two-dimensional perovskites are simultaneously generated at the interface between the FAPbI3 layer and the hole transport layer, at the interface between the FAPbI3 layer and the electron transport layer, and at each grain boundary within the FAPbI3 layer, thus forming the FAPbI3 three-dimensional two-dimensional core-shell self-encapsulated perovskite light absorption layer. The thickness of the FAPbI3 three-dimensional two-dimensional core-shell self-encapsulated perovskite light-absorbing layer is 500~800 nm. With FAPbI3 three-dimensional perovskite as the core, the residual PbI2 is reacted with or replaced by the pyridylamine derivative hydrohalate at its grain boundaries and at the interfaces with the hole transport layer and the electron transport layer, respectively. + Ions generate a two-dimensional perovskite shell.

[0011] Furthermore, the hole transport layer has a thickness of 15-25 nm and is prepared using NiO nanocrystals with a particle size of 3-5 nm; the hole transport layer is a NiO nanocrystal hole transport layer. The electron transport layer has a thickness of 15-30 nm and is prepared using SnO2 nanorods with a particle size of 2-4 nm and an aspect ratio of 3-5; the electron transport layer is a SnO2 nanorod electron transport layer. The AZO electrode layer is an aluminum-doped zinc oxide top electrode. The hole transport layer has a planar structure. The electron transport layer has a planar structure.

[0012] Furthermore, the pyridylamine derivative hydrohalate is attached to the surface of NiO nanocrystals and SnO2 nanorods through ligand exchange; In preparing the PbI2 layer, a pyridylamine derivative hydrohalate is added to the PbI2 solution.

[0013] Furthermore, the pyridylamine derivative hydrohalate is a compound whose molecular structure contains both a pyridine ring and an amino group and forms a salt with a hydrohalic acid. The amino group is -NH2, -NHR, or -NR2, and R is an alkyl, aryl, or other non-hydrogen organic substituent. The hydrohalic acid includes HCl, HBr, HI, or HF.

[0014] Further, the pyridylamine derivative hydrohalate is 4-formamidinylpyridine dihydrochloride, 2-formamidinylpyridine hydrochloride, 2-(2-pyridyl)ethylamine hydroiodate, 3-pyridineethylamine hydroiodate, or 2-pyridinemethylamine hydrochloride.

[0015] A method for fabricating a three-dimensional / two-dimensional core-shell self-encapsulated inverted perovskite solar cell includes the following steps: Step 1: Disperse NiO nanocrystals with an oil amine ligand and a particle size of 3-5 nm in n-hexane to prepare a NiO nanocrystal dispersion with a concentration of 2-8 mg / mL. The dispersion was spin-coated onto the conductive layer of conductive glass in two steps. First, the dispersion was spin-coated at 400-800 rpm for 3-5 seconds to allow it to spread and wet the conductive layer. Then, the dispersion was spin-coated at 3000-5000 rpm for 30-60 seconds to control the thickness of the NiO nanocrystalline particle layer. The NiO nanocrystal layer was placed in an N,N-dimethylformamide solution containing a mixture of NOBF4 and pyridylamine derivative hydrohalides at 40-60°C for 6-12 hours to fully complete ligand exchange. The concentration of NOBF4 was 10-25 mg / mL and the concentration of pyridylamine derivative hydrohalides was 2.5-6 mg / mL. The strong oxidizing nitrosamine cations underwent electrophilic addition and oxidation with oleylamine to generate non-coordinating nitrosamines, which desorbed from the surface of the NiO nanocrystals. The NiO nanocrystal particles spontaneously and tightly bound together and adsorbed the pyridylamine derivative hydrohalides to form a hole transport layer with a thickness of 15-25 nm. After rinsing with anhydrous ethanol, the layer was dried by heating at 50-100°C for 15-30 minutes. Step 2: Disperse SnO2 nanorods with a particle size of 2-4 nm, an aspect ratio of 3-5, and containing oleylamine ligands in toluene to prepare a SnO2 nanorod toluene dispersion with a concentration of 10-50 mg / mL; dissolve NOBF4 and pyridylamine derivative hydrohalide in N,N-dimethylformamide to prepare a mixed solution, so that the concentrations of NOBF4 and pyridylamine derivative hydrohalide are 5-12 mg / mL and 2.5-6 mg / mL, respectively. Under magnetic stirring at 500-1000 rpm, a N,N-dimethylformamide solution containing 1-4 times the volume of NOBF4 and pyridylamine derivative hydrohalide salts was added dropwise to the SnO2 nanorod toluene dispersion. The mixture was stirred continuously for 0.5-2 hours to completely transfer the SnO2 nanorods from the upper toluene solution to the lower N,N-dimethylformamide solution, thus completing the ligand exchange. Collect the lower layer solution, add 2 to 5 times its volume of acetone to precipitate the SnO2 nanorods, and centrifuge at 6000 to 10000 rpm for 15 to 30 minutes, and collect the centrifuged material. The centrifuged material was ultrasonically dispersed in isopropanol at 150-180W to prepare an isopropanol dispersion of SnO2 nanorods containing pyridylamine derivative hydrohalate ligands at a concentration of 2-8 mg / mL. Step 3: Prepare a solution of N,N-dimethylformamide and dimethyl sulfoxide with a concentration of 1.2~1.5 M PbI2, with a volume ratio of N,N-dimethylformamide to dimethyl sulfoxide of 4:1~9:1. Then add pyridinylamine derivative hydrohalate to the solution, with a concentration of 2~10 mg / mL. Continue spin-coating the solution onto the planar hole transport layer prepared in step 1. Use a two-step spin-coating process: first spin-coat at 400-800 rpm for 5-10 s to allow the PbI2 solution to fully spread and wet the hole transport layer; then spin-coat at 1000-3000 rpm for 30-60 s to control the thickness of the PbI2 layer; and finally anneal at 50-100℃ for 15-30 minutes. Step 4: Prepare isopropanol mixed solutions of formamidin hydroiodate and methylamine hydrochloride with concentrations of 0.6~1.0 M and 0.02~0.08 M, respectively; After the PbI2 layer prepared in step 3 has cooled to room temperature, a mixed solution of formamidinium hydroiodide and methylamine hydrochloride in isopropanol is spin-coated. The spin-coating is done in two steps: first, spin-coat at 400-800 rpm for 10-30 s to allow the mixed solution of formamidinium hydroiodide and methylamine hydrochloride in isopropanol to fully spread and wet the PbI2 layer; then spin-coat at 2000-5000 rpm for 30-60 s to allow the PbI2 to fully react with the formamidinium hydroiodide and methylamine hydrochloride to form an FAPbI3 layer. Continue spin-coating the isopropanol dispersion of SnO2 nanorods containing pyridylamine derivative hydrohalate ligands prepared in step 2. Use a two-step spin-coating method: first spin-coat at 400-800 rpm for 5-10 s to allow the dispersion to fully spread and wet the FAPbI3 layer, and then spin-coat at 3000-5000 rpm for 30-60 s to control the thickness of the SnO2 nanorod layer to be 15-30 nm. Step 5: Anneal the sample prepared in Step 4 at 150-170 °C for 30-60 minutes to generate a three-dimensional perovskite with FAPbI3 as the core. At its grain boundaries and interfaces with the hole transport layer and electron transport layer, the residual PbI2 is reacted with or replaced by pyridylamine derivative hydrohalates. + A three-dimensional two-dimensional core-shell self-encapsulated perovskite light-absorbing layer with a thickness of 500~800 nm is generated by ion-generated two-dimensional perovskite shell. Finally, an AZO top electrode is sputtered onto the electron transport layer to obtain a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell.

[0016] By adopting the above technical solution, the present invention provides a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell and its fabrication method, which has the following beneficial effects: The three-dimensional two-dimensional core-shell self-encapsulation structure uses a three-dimensional perovskite core to ensure efficient generation and transport of photogenerated carriers; using a two-dimensional perovskite as the grain boundary shell of the three-dimensional perovskite and the interface transition layer between the three-dimensional perovskite and the hole and electron transport layer provides a strong hydrophobic barrier and defect passivation. The strength of hydrophobicity is characterized by water contact angle data; an increase in water contact angle of 25-35% reduces the defect density of the perovskite light absorption layer by 30-50%, achieving "high-efficiency power generation in the core and self-encapsulation protection in the shell." This ensures high photoelectric conversion efficiency and long-term stability of the solar cell, with a photoelectric conversion efficiency reaching over 25%, typically around 24% to 25%. This represents a 10%-20% improvement in efficiency compared to traditional pure FAPbI3 perovskite light absorption layer devices, providing key technical support for the industrialization of perovskite solar cells. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the battery structure of the present invention and the separation and transport of photogenerated carriers during the photoelectric conversion process.

[0018] In the picture: ITO is a conductive glass with an indium-doped SnO2 conductive layer; HTL is a hole transport layer prepared from NiO nanocrystal particles; PVK is a self-encapsulated perovskite light-absorbing layer with a three-dimensional FAPbI3 core and a two-dimensional shell formed by the reaction with pyridylamine derivative hydrohalides. ETL is a planar electron transport layer fabricated from SnO2 nanorods; AZO is an aluminum-doped zinc oxide top electrode. Detailed Implementation

[0019] Example 1 I. Preparation This invention discloses a method for fabricating a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell, comprising the following steps: Step 1: Disperse NiO nanocrystals with an oil amine ligand and a particle size of 3.6 nm in n-hexane to prepare a NiO nanocrystal dispersion with a concentration of 2 mg / mL. The dispersion was spin-coated onto the conductive layer of conductive glass in two steps. First, the dispersion was spin-coated at 500 rpm for 5 seconds to allow it to spread and wet the conductive layer. Then, the dispersion was spin-coated at 4000 rpm for 30 seconds to control the thickness of the NiO nanocrystal particle layer. NiO nanocrystal particles were placed in a solution of N,N-dimethylformamide (DMF) containing a mixture of nitrosotetrafluoroborate (NOBF4) (15 mg / mL) and 4-formamidinium pyridine dihydrochloride (4-FAPyCl2) (4 mg / mL) at 40 °C for 10 hours. Through electrophilic addition and oxidation of oleylamine with strongly oxidizing nitrosamine cations, non-coordinating nitrosamines were generated and desorbed from the NiO nanocrystal surface. The clean NiO nanocrystals were extremely unstable, and the particles spontaneously and tightly bound together, adsorbing 4-FAPyCl2 to form a stable hole transport layer (20 nm thick). This hole transport layer was the NiO nanocrystal hole transport layer. After rinsing with anhydrous ethanol, the particles were dried at 100 °C for 30 minutes.

[0020] Step 2: Disperse SnO2 nanorods with a particle size of 3 nm, an aspect ratio of 5, and containing oleylamine ligands in toluene to prepare a SnO2 nanorod toluene dispersion with a concentration of 25 mg / mL. A mixed solution was prepared by dissolving NOBF4 and 4-FAPyCl2 in DMF, with the concentrations of NOBF4 and 4-FAPyCl2 being 5 mg / mL and 2.5 mg / mL, respectively, to obtain a mixed DMF solution of NOBF4 and 4-FAPyCl2. Under magnetic stirring at 600 rpm, a mixed DMF solution of NOBF4 and 4-FAPyCl2 with a volume of 4 times its own volume was slowly added dropwise to the SnO2 nanorod toluene dispersion. The stirring was continued for 2 hours to completely transfer the SnO2 nanorods from the upper toluene solution to the lower DMF solution, thus completing the ligand exchange. Collect the lower layer solution, add acetone equivalent to 3 times the volume of the lower layer solution to precipitate the SnO2 nanorods, and centrifuge at 8000 rpm for 15 minutes to collect the centrifuged material; disperse the centrifuged material in isopropanol using 180 W ultrasonication to prepare a SnO2 nanorod isopropanol dispersion with a concentration of 3 mg / mL containing 4-FAPyCl2 ligand.

[0021] Step 3: Prepare a 1.5 M PbI2 solution of DMF and dimethyl sulfoxide (DMSO) with a volume ratio of DMF to DMSO of 9:1. Add 4-FAPyCl2 to the solution to make the concentration of 4-FAPyCl2 4 mg / mL. This solution will be referred to as the PbI2 solution below. The PbI2 solution was spin-coated onto the planar hole transport layer prepared in step 1 using a two-step spin-coating method. First, the PbI2 solution was spin-coated at 500 rpm for 10 s to allow it to fully spread and wet the hole transport layer. Then, the PbI2 layer was spin-coated at 2000 rpm for 30 s to control its thickness. Finally, the layer was annealed at 100°C for 15 minutes.

[0022] Step 4: Prepare mixed solutions of formamidin hydroiodide (FAI) and methylamine hydrochloride (MACl) in isopropanol at concentrations of 0.8 M and 0.05 M, respectively; After the PbI2 layer prepared in step 3 has cooled to room temperature, spin-coat a mixed solution of FAI and MACl isopropanol. The spin-coating is done in two steps: first, spin-coat at 500 rpm for 10 s to allow the mixed solution of FAI and MACl isopropanol to fully spread and wet the PbI2 layer; then spin-coat at 2500 rpm for 30 s to allow the PbI2 to fully react with FAI and MACl to form a formicinium triiodolead(II)ate (FAPbI3) layer. Continue spin-coating the isopropanol dispersion of SnO2 nanorods containing 4-FAPyCl2 ligands prepared in step 2. Use a two-step spin-coating process: first, spin-coat at 500 rpm for 10 s to allow the dispersion to fully spread and wet the FAPbI3 layer; then spin-coat at 4000 rpm for 50 s to control the thickness of the electron transport layer (25 nm). The electron transport layer is a SnO2 nanorod electron transport layer with a planar structure.

[0023] Step 5: Anneal the sample prepared in Step 4 at 160 °C for 30 minutes to generate a three-dimensional perovskite with FAPbI3 core. At its grain boundaries and interfaces with the hole transport layer and electron transport layer, 4-FAPyCl2 reacts with residual PbI2 or replaces FA. + A three-dimensional two-dimensional core-shell self-encapsulated perovskite light-absorbing layer (700 nm) with ion-generated two-dimensional perovskite shell. Finally, an AZO top electrode (aluminum-doped zinc oxide top electrode) is sputtered onto the electron transport layer to obtain a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell.

[0024] It should be noted that, in this invention, in addition to 4-FAPyCl2, pyridylamine derivative hydrohalides such as 2-formamidinylpyridine hydrochloride, 2-(2-pyridyl)ethylamine hydroiodide, 3-pyridineethylamine hydroiodide, or 2-pyridinemethylamine hydrochloride may also be used, depending on the desired effect.

[0025] Pyridylamine derivative hydrohalides are compounds whose molecular structure contains both a pyridine ring and an amino group (-NH2 / -NHR / -NR2) and forms salts with hydrohalic acids (HCl, HBr, HI, HF). 4-FAPyCl2 in this embodiment is a preferred example.

[0026] This invention discloses a three-dimensional / two-dimensional core-shell self-encapsulated inverted perovskite solar cell, such as... Figure 1As shown, the solar cell comprises, sequentially arranged, a conductive glass conductive layer, a hole transport layer, a FAPbI3 three-dimensional core-shell self-encapsulated perovskite light-absorbing layer, an electron transport layer, and an AZO electrode layer. The hole transport layer is stacked on the conductive glass conductive layer of the solar cell. A PbI2 layer for two-step preparation of the FAPbI3 layer is formed on the hole transport layer. The PbI2 layer is prepared by coating the hole transport layer with a PbI2 solution. The electron transport layer is formed on the FAPbI3 layer, and the AZO electrode layer is sputtered onto the electron transport layer. The two-step method involves first preparing PbI2, and then reacting it with an ammonium salt to generate FAPbI3.

[0027] The hole transport layer, the PbI2 layer, and the electron transport layer all introduce organic macrocations for generating two-dimensional titanium ore, and the source of the organic macrocations is a pyridylamine derivative hydrohalate. During the preparation of the FAPbI3 three-dimensional two-dimensional core-shell self-encapsulated inverse perovskite light absorption layer, two-dimensional perovskites are simultaneously generated at the interface between the FAPbI3 layer and the hole transport layer, at the interface between the FAPbI3 layer and the electron transport layer, and at each grain boundary within the FAPbI3 layer, thus forming the FAPbI3 three-dimensional two-dimensional core-shell self-encapsulated perovskite light absorption layer. The thickness of the FAPbI3 three-dimensional two-dimensional core-shell self-encapsulated perovskite light-absorbing layer is 500~800 nm. With FAPbI3 three-dimensional perovskite as the core, pyridylamine derivative hydrohalates react with residual PbI2 or replace FA at its grain boundaries and at the interfaces with the hole transport layer and the electron transport layer, respectively. + Ions generate a two-dimensional perovskite shell.

[0028] This invention discloses a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell. The three-dimensional two-dimensional core-shell self-encapsulation structure uses a three-dimensional perovskite core to ensure efficient photogenerated carrier generation and transport. The two-dimensional perovskite serves as the grain boundary shell of the three-dimensional perovskite and the interface transition layer between the three-dimensional perovskite and the hole and electron transport layer, providing a strong hydrophobic barrier and defect passivation. The strength of hydrophobicity is characterized by water contact angle data; an increase of 25-35% in the water contact angle reduces the defect density of the perovskite light absorption layer by 30-50%, achieving "high-efficiency power generation in the core and self-encapsulated protection in the shell." This ensures high photoelectric conversion efficiency and long-term stability of the solar cell, achieving a photoelectric conversion efficiency of over 25%, compared to the typical 24%-25% for solar cells. This represents a 10-20% efficiency improvement over traditional pure FAPbI3 perovskite light absorption layer devices, providing key technological support for the industrialization of perovskite solar cells.

[0029] II. Performance Testing This invention discloses a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell. Compared with traditional three-dimensional two-dimensional composite inverted perovskite solar cells (pure FAPbI3 perovskite light-absorbing layer), the two-dimensional perovskite is confined to the three-dimensional perovskite grain boundaries and the interface between the three-dimensional perovskite and the hole and electron transport layer, achieving "high-efficiency power generation in the core and self-encapsulation and protection in the shell," thus ensuring high photoelectric conversion efficiency and long-term stability of the solar cell. A 1 cm [structure / material] was prepared. 2 The photoelectric conversion efficiency of the three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell reaches 24.5%~25.5%, which is 10%~20% higher than that of traditional pure FAPbI3 perovskite light absorption layer devices.

[0030] Test method: Current density-voltage (V) of inverted perovskite solar cells J-V The characteristic curve test was conducted using a solar simulator (SS-F5-3A, Taiwan Guangyan Technology) equipped with a Keithley 2400 digital source meter. The light source was set to the standard AM1.5G solar spectrum with a light intensity of 100 mW·cm. -2 Before each test, the simulator's light intensity is precisely calibrated using a certified standard silicon reference cell, and the irradiance is confirmed using a calibration spectrometer. J-V The curve's scan range is set to 0.1 V to 1.2 V, forward scan ( (0.1 V → 1.2 V). During the test, the device electrodes were reversed, the voltage step size was set to 20 mV, and the delay time was 10 ms.

[0031] Long-term stability data are obtained by testing the photoelectric conversion efficiency of the device after it has been exposed to standard simulated sunlight for 1000 hours, and then comparing it with the initial efficiency to calculate the percentage.

[0032] Test data: The following shows 5 groups (A, B, C, D, E) that passed. J-V The open-circuit voltage obtained by the test ( V oc ), short-circuit current ( J sc ), fill factor ( FF The photoelectric conversion efficiency (PCE) data are shown in Table 1 below. Furthermore, the efficiency of this group of devices remained at 95% of its initial value after 1000 hours of continuous exposure to standard simulated sunlight.

[0033] Table 1. Device in Example 1 J-V Four photoelectric performance parameters obtained in the test

[0034] As shown in Table 1 above, the device prepared by this invention has… J-V During testing, it consistently exhibited high efficiency (>24.6%), high open-circuit voltage (≈1.19 V), and high fill factor (>81%), with minimal performance fluctuations; after 1000 hours of continuous exposure to standard simulated sunlight, its efficiency remained at 95% of its initial value. This ensures high photoelectric conversion efficiency, good repeatability, and long-term stability of the solar cell, providing key technological support for the industrialization of perovskite solar cells.

[0035] Example 2 I. Preparation A method for fabricating a three-dimensional / two-dimensional core-shell self-encapsulated inverted perovskite solar cell includes the following steps: Step 1: NiO nanocrystals with a particle size of 5 nm containing oleylamine ligands were dispersed in n-hexane to prepare a NiO nanocrystal dispersion with a concentration of 4 mg / mL. This dispersion was then spin-coated onto a conductive glass conductive layer using a two-step spin-coating process: first, spin-coating at 500 rpm for 5 s to allow the dispersion to fully spread and wet the conductive layer; then, spin-coating at 5000 rpm for 30 s to control the thickness of the NiO nanocrystal layer. The NiO nanocrystal film was placed in a DMF solution of NOBF4 (25 mg / mL) and 2-(2-pyridyl)ethylamine hydroiodate (2-PyEAI) (6 mg / mL) at 60 ℃ for 6 hours. Through electrophilic addition and oxidation of oleylamine with strongly oxidizing nitrosamine cations, non-coordinating nitrosamines were generated and desorbed from the NiO nanocrystal surface. The clean NiO nanocrystals were extremely unstable, and the particles spontaneously and tightly bound together and adsorbed 2-PyEAI, forming a stable hole transport layer (25 mg / mL). After being rinsed with anhydrous ethanol, the sample was dried at 100°C for 30 minutes.

[0036] Step 2: Disperse 2 nm, aspect ratio 4, oleylamine ligand-containing SnO2 nanorods in toluene to prepare a 25 mg / mL SnO2 nanorod toluene dispersion. Dissolve NOBF4 and 2-PyEAI in DMF to prepare a mixed solution with NOBF4 and 2-PyEAI concentrations of 6 mg / mL and 3 mg / mL, respectively. Under magnetic stirring at 600 rpm, slowly add 4 times the volume of the NOBF4 and 2-PyEAI mixed DMF solution to the SnO2 nanorod toluene dispersion, and continue stirring for 2 hours to completely transfer the SnO2 nanorods from the upper toluene solution to the lower DMF solution, completing the ligand exchange. Collect the lower solution, add 3 times the volume of acetone to precipitate the SnO2 nanorods, and centrifuge at 8000 rpm for 15 minutes, collecting the centrifuged material. Sonicate the centrifuged material in isopropanol at 180 W to prepare a 5% concentration. mg / mL SnO2 nanorod isopropanol dispersion containing 2-PyEAI ligand.

[0037] Step 3: Prepare a 1.2 M PbI2 solution of DMF and DMSO (volume ratio 9:1), and add 2-PyEAI (concentration 4 mg / mL). Spin-coat this solution onto the planar hole transport layer prepared in Step 1 using a two-step spin-coating method. First, spin-coat at 500 rpm for 10 s to allow the PbI2 solution to fully spread and wet the hole transport layer. Then, spin-coat at 2500 rpm for 30 s to control the thickness of the PbI2 layer. Finally, anneal at 100℃ for 15 minutes.

[0038] Step 4: Prepare mixed solutions of FAI and MACl isopropanol with concentrations of 0.6 M and 0.02 M, respectively. After the PbI2 layer prepared in Step 3 has cooled to room temperature, spin-coat the mixed solution of FAI and MACl isopropanol using a two-step spin-coating method. First, spin-coat at 500 rpm for 10 s to allow the mixed solution of FAI and MACl to fully spread and wet the PbI2 layer. Then, spin-coat at 2500 rpm for 30 s to allow the PbI2 to fully react with FAI and MACl to form the FAPbI3 layer. Continue spin-coating the isopropanol dispersion of SnO2 nanorods containing 2-PyEAI ligand prepared in Step 2 using a two-step spin-coating method. First, spin-coat at 500 rpm for 10 s to allow the dispersion to fully spread and wet the FAPbI3 layer. Then, spin-coat at 3000 rpm for 50 s to control the thickness of the electron transport layer (30 nm). The electron transport layer is the SnO2 nanorod electron transport layer. The electron transport layer has a planar structure.

[0039] Step 5: Anneal the sample prepared in Step 4 at 160 °C for 30 minutes to generate a three-dimensional perovskite with FAPbI3 as the core. At its grain boundaries and interfaces with the hole and electron transport layers, 2-PyEAI reacts with the residual PbI2 or replaces FA.+ A three-dimensional two-dimensional core-shell self-encapsulated perovskite light-absorbing layer (500 nm) is generated by ion generation of a two-dimensional perovskite shell; finally, an AZO top electrode is sputtered onto the electron transport layer to obtain a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell.

[0040] II. Performance Testing: This invention discloses a three-dimensional two-dimensional core-shell self-encapsulated inverse perovskite solar cell. Pyridylamine derivative hydrohalides are attached as ligands to the surfaces of NiO nanocrystals and SnO2 nanorods. By controlling the degree of ligand exchange and the thickness of the carrier transport layer, the amount of pyridylamine derivative hydrohalides is precisely controlled, thereby controlling the distribution and thickness of the two-dimensional perovskite shell at the interface. This effectively controls interface defects while ensuring smooth carrier transport. A 1 cm⁻¹ perovskite solar cell was prepared. 2 The photoelectric conversion efficiency of the three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell reaches 23.5%~24.5%, which is 5%~15% higher than that of traditional pure FAPbI3 perovskite light absorption layer devices.

[0041] Test method: Inverted perovskite solar cells J-V Characteristic curve testing was performed using a solar simulator (SS-F5-3A, Taiwan Guangyan Technology) equipped with a Keithley 2400 digital source meter. The light source was set to the standard AM 1.5G solar spectrum with a light intensity of 100 mW·cm². -2 Before each test, the simulator's light intensity is precisely calibrated using a certified standard silicon reference cell, and the irradiance is confirmed using a calibration spectrometer. J-V The curve's scan range is set to 0.1 V to 1.2 V, forward scan ( (0.1 V → 1.2 V). During the test, the device electrodes were reversed, the voltage step size was set to 20 mV, and the delay time was 10 ms.

[0042] Long-term stability data are obtained by testing the photoelectric conversion efficiency of the device after it has been exposed to standard simulated sunlight for 1000 hours, and then comparing it with the initial efficiency to calculate the percentage.

[0043] Test data: The following shows 5 groups (A, B, C, D, E) that passed. J-V Test results V oc , J sc , FF The test results, along with PCE data, are shown in Table 2 below. Furthermore, after 1000 hours of continuous exposure to standard simulated sunlight, the efficiency of this group of devices remains at 93% of its initial value.

[0044] Table 2. Devices in Example 2 J-V Four photoelectric performance parameters obtained in the test

[0045] As shown in Table 2 above, the device prepared by this invention has… J-V During testing, the cell consistently exhibited an efficiency of approximately 24%, a high open-circuit voltage (≈1.19 V), and a high fill factor (>80%), with minimal performance fluctuations. After 1000 hours of continuous exposure to standard simulated sunlight, the efficiency remained at 93% of its initial value. This ensures high photoelectric conversion efficiency, good repeatability, and long-term stability of the solar cell, validating the effectiveness of the proposed technology and providing crucial technical support for the industrialization of perovskite solar cells.

[0046] Comparative Example 1 Compared with Example 1, Comparative Example 1 did not add pyridylamine derivative hydrohalates that can generate two-dimensional perovskites to any of the functional layers, and prepared a conventional inverted perovskite solar cell containing a hole transport layer, an FAPbI3 perovskite light absorption layer and an electron transport layer.

[0047] I. Preparation Fabricating a conventional inverted perovskite solar cell containing a hole transport layer, a FAPbI3 perovskite light-absorbing layer, and an electron transport layer includes the following steps: Step 1: Disperse NiO nanocrystals with an oil amine ligand and a particle size of 3.6 nm in n-hexane to prepare a NiO nanocrystal dispersion with a concentration of 2 mg / mL. The dispersion was spin-coated onto the conductive layer of conductive glass in two steps. First, the dispersion was spin-coated at 500 rpm for 5 seconds to allow it to spread and wet the conductive layer. Then, the dispersion was spin-coated at 4000 rpm for 30 seconds to control the thickness of the NiO nanocrystal particle layer. The NiO nanocrystal layer was placed in a DMF solution of NOBF4 (15 mg / mL) at 40 °C for 10 hours. The strong oxidizing nitrosamine cations reacted with oleylamine via electrophilic addition and oxidation to generate non-coordinating nitrosamines, which desorbed from the surface of the NiO nanocrystals. The clean NiO nanocrystals were extremely unstable, and the particles easily and spontaneously bonded together to form a stable hole transport layer (20 nm thick). After rinsing with anhydrous ethanol, the particles were dried by heating at 100 °C for 30 minutes.

[0048] Step 2: Disperse SnO2 nanorods with a particle size of 3 nm, an aspect ratio of 5, and containing oleylamine ligands in toluene to prepare a SnO2 nanorod toluene dispersion with a concentration of 25 mg / mL. Prepare a DMF solution with a concentration of 5 mg / mL NOBF4; Under magnetic stirring at 600 rpm, a DMF solution of NOBF4 with a volume of 4 times its own volume was slowly added dropwise to the SnO2 nanorod toluene dispersion. The stirring was continued for 2 hours to completely transfer the SnO2 nanorods from the upper toluene solution to the lower DMF solution, thus completing the ligand exfoliation. Collect the lower layer solution, add acetone equivalent to 3 times the volume of the lower layer solution to precipitate the SnO2 nanorods, and centrifuge at 8000 rpm for 15 minutes to collect the centrifuged material; disperse the centrifuged material in isopropanol using 180 W ultrasonication to prepare a SnO2 nanorod isopropanol dispersion with a concentration of 3 mg / mL.

[0049] Step 3: Prepare a 1.5 M PbI2 solution of DMF and DMSO with a volume ratio of 9:1. This solution will be referred to as the PbI2 solution below. The PbI2 solution was spin-coated onto the planar hole transport layer prepared in step 1 using a two-step spin-coating method. First, the PbI2 solution was spin-coated at 500 rpm for 10 s to allow it to fully spread and wet the hole transport layer. Then, the PbI2 layer was spin-coated at 2000 rpm for 30 s to control its thickness. Finally, the layer was annealed at 100°C for 15 minutes.

[0050] Step 4: Prepare mixed solutions of FAI and MACl isopropanol with concentrations of 0.8 M and 0.05 M, respectively; After the PbI2 layer prepared in step 3 has cooled to room temperature, spin-coat a mixed solution of FAI and MACl isopropanol. The spin-coating is done in two steps: first, spin-coat at 500 rpm for 10 s to allow the mixed solution of FAI and MACl to fully spread and wet the PbI2 layer; then spin-coat at 2500 rpm for 30 s to allow the PbI2 to fully react with FAI and MACl to form the FAPbI3 layer. Continue spin-coating the SnO2 nanorod isopropanol dispersion prepared in step 2. Use a two-step spin-coating method: first spin-coat at 500 rpm for 10 s to allow the dispersion to fully spread and wet the FAPbI3 layer, and then spin-coat at 4000 rpm for 50 s to control the SnO2 nanorod layer thickness (25 nm).

[0051] Step 5: Place the sample prepared in step 4 at 160 °C for annealing for 30 minutes to allow the FAPbI3 perovskite light-absorbing layer to fully crystallize (700 nm). Finally, an AZO top electrode is sputtered onto the electron transport layer to obtain an inverted perovskite solar cell.

[0052] II. Performance Testing The 1 cm prepared in this comparative example 2 Traditional inverted perovskite solar cells achieve a photoelectric conversion efficiency of 21.5% to 22.5%.

[0053] Test method: Inverted perovskite solar cells J-V Characteristic curve testing was performed using a solar simulator (SS-F5-3A, Taiwan Guangyan Technology) equipped with a Keithley 2400 digital source meter. The light source was set to the standard AM 1.5G solar spectrum with a light intensity of 100 mW·cm². -2 Before each test, the simulator's light intensity is precisely calibrated using a certified standard silicon reference cell, and the irradiance is confirmed using a calibration spectrometer. J-V The curve's scan range is set to 0.1 V to 1.2 V, forward scan ( (0.1 V → 1.2 V). During the test, the device electrodes were reversed, the voltage step size was set to 20 mV, and the delay time was 10 ms.

[0054] Long-term stability data are obtained by testing the photoelectric conversion efficiency of the device after it has been exposed to standard simulated sunlight for 1000 hours, and then comparing it with the initial efficiency to calculate the percentage.

[0055] Test data: The following shows 5 groups (A, B, C, D, E) that passed. J-V Test results V oc , J sc , FF The test results, along with PCE data, are shown in Table 3 below. Furthermore, after 1000 hours of continuous exposure to standard simulated sunlight, the efficiency of this group of devices remains at 82% of its initial value.

[0056] Table 3 Comparative Example 1 Device in J-V Four photoelectric performance parameters obtained in the test

[0057] As shown in Table 3 above, the device in Comparative Example 1... J-V During testing, the photoelectric performance parameters remained relatively stable, with the photoelectric conversion efficiency consistently ranging from 22.0% to 22.5% with minimal fluctuations, indicating good repeatability of the device structure. Compared to Example 1, the relatively lower efficiency is mainly due to the lower short-circuit current and fill factor, demonstrating the significant effectiveness of Example 1 in defect control.

[0058] Comparative Example 2 Compared with Example 1, Comparative Example 2 only added pyridylamine derivative hydrohalate to the PbI2 solution during the two-step preparation of the perovskite light-absorbing layer, and generated two-dimensional perovskite in situ at the grain boundaries during the FAPbI3 growth process. However, no two-dimensional perovskite was generated at the interface between the perovskite light-absorbing layer and the hole transport layer and electron transport layer.

[0059] I. Preparation The fabrication of an inverted perovskite solar cell comprising a hole transport layer, a perovskite light-absorbing layer formed in situ at FAPbI3 grain boundaries, and an electron transport layer includes the following steps: Step 1: Disperse NiO nanocrystals with an oil amine ligand and a particle size of 3.6 nm in n-hexane to prepare a NiO nanocrystal dispersion with a concentration of 2 mg / mL. The dispersion was spin-coated onto the conductive layer of conductive glass in two steps. First, the dispersion was spin-coated at 500 rpm for 5 seconds to allow it to spread and wet the conductive layer. Then, the dispersion was spin-coated at 4000 rpm for 30 seconds to control the thickness of the NiO nanocrystal particle layer. The NiO nanocrystal layer was placed in a DMF solution of NOBF4 (15 mg / mL) at 40 °C for 10 hours. The strong oxidizing nitrosamine cations reacted with oleylamine via electrophilic addition and oxidation to generate non-coordinating nitrosamines, which desorbed from the surface of the NiO nanocrystals. The clean NiO nanocrystals were extremely unstable, and the particles easily and spontaneously bonded together to form a stable hole transport layer (20 nm thick). After rinsing with anhydrous ethanol, the particles were dried by heating at 100 °C for 30 minutes.

[0060] Step 2: Disperse SnO2 nanorods with a particle size of 3 nm, an aspect ratio of 5, and containing oleylamine ligands in toluene to prepare a SnO2 nanorod toluene dispersion with a concentration of 25 mg / mL. Prepare a DMF solution with a concentration of 5 mg / mL NOBF4; Under magnetic stirring at 600 rpm, a DMF solution of NOBF4 with a volume of 4 times its own volume was slowly added dropwise to the SnO2 nanorod toluene dispersion. The stirring was continued for 2 hours to completely transfer the SnO2 nanorods from the upper toluene solution to the lower DMF solution, thus completing the ligand exchange. Collect the lower layer solution, add acetone equivalent to 3 times the volume of the lower layer solution to precipitate the SnO2 nanorods, and centrifuge at 8000 rpm for 15 minutes to collect the centrifuged material; disperse the centrifuged material in isopropanol using 180 W ultrasonication to prepare a SnO2 nanorod isopropanol dispersion with a concentration of 3 mg / mL.

[0061] Step 3: Prepare a 1.5 M PbI2 solution of DMF and DMSO with a volume ratio of 9:1. Add 4-FAPyCl2 to make the concentration of 4-FAPyCl2 4 mg / mL. This solution will be referred to as the PbI2 solution below. The PbI2 solution was spin-coated onto the planar hole transport layer prepared in step 1 using a two-step spin-coating method. First, the PbI2 solution was spin-coated at 500 rpm for 10 s to allow it to fully spread and wet the hole transport layer. Then, the PbI2 layer was spin-coated at 2000 rpm for 30 s to control its thickness. Finally, the layer was annealed at 100°C for 15 minutes.

[0062] Step 4: Prepare mixed solutions of FAI and MACl isopropanol with concentrations of 0.8 M and 0.05 M, respectively; After the PbI2 layer prepared in step 3 has cooled to room temperature, spin-coat a mixed solution of FAI and MACl isopropanol. The spin-coating is done in two steps: first, spin-coat at 500 rpm for 10 s to allow the mixed solution of FAI and MACl isopropanol to fully spread and wet the PbI2 layer; then spin-coat at 2500 rpm for 30 s to allow Pb2 to fully react with FAI and MACl to form the FAPbI3 layer. Continue spin-coating the SnO2 nanorod isopropanol dispersion prepared in step 2. Use a two-step spin-coating method: first spin-coat at 500 rpm for 10 s to allow the dispersion to fully spread and wet the FAPbI3 layer, and then spin-coat at 4000 rpm for 50 s to control the SnO2 nanorod layer thickness (25 nm).

[0063] Step 5: Anneal the sample prepared in Step 4 at 160 °C for 30 minutes to allow FAPbI3 to fully crystallize. Simultaneously, 4-FAPyCl2 reacts with or replaces residual PbI2 at the grain boundaries of FAPbI3. + Perovskite light-absorbing layer (700 nm) with ion-generated two-dimensional perovskite shell. Finally, an AZO top electrode is sputtered onto the electron transport layer to obtain an inverted perovskite solar cell.

[0064] II. Performance Testing Prepared 1 cm 2 The photoelectric conversion efficiency of FAPbI3 grain boundary inverted perovskite solar cells with two-dimensional shells reaches 23.0%~24.0%, which is 2%~7% higher than that of traditional FAPbI3 perovskite light-absorbing layer devices.

[0065] Test method: Inverted perovskite solar cells J-VCharacteristic curve testing was performed using a solar simulator (SS-F5-3A, Taiwan Guangyan Technology) equipped with a Keithley 2400 digital source meter. The light source was set to the standard AM 1.5G solar spectrum with a light intensity of 100 mW·cm². -2 Before each test, the simulator's light intensity is precisely calibrated using a certified standard silicon reference cell, and the irradiance is confirmed using a calibration spectrometer. J-V The curve's scan range is set to 0.1 V to 1.2 V, forward scan ( (0.1 V → 1.2 V). During the test, the device electrodes were reversed, the voltage step size was set to 20 mV, and the delay time was 10 ms.

[0066] Long-term stability data are obtained by testing the photoelectric conversion efficiency of the device after it has been exposed to standard simulated sunlight for 1000 hours, and then comparing it with the initial efficiency to calculate the percentage.

[0067] Test data: The following shows 5 groups (ABCDE) obtained through the JV test. V oc , J sc , FF The test results, along with PCE data, are shown in Table 4 below. Furthermore, after 1000 hours of continuous exposure to standard simulated sunlight, the efficiency of this group of devices remains at 88% of its initial value.

[0068] Table 4 Comparative Example 2 Devices J-V Four photoelectric performance parameters obtained in the test

[0069] As shown in Table 4 above, the device in Comparative Example 2... J-V During the test, the photoelectric performance parameters were relatively stable. The open-circuit voltage remained stable at 1.18 V, and the short-circuit current, except for slightly lower for device C, was above 24.00 mA·cm⁻¹. -2 The fill factor was higher than 80.00%, and the final photoelectric conversion efficiency was higher than 23.00%. Compared with Comparative Example 1, this shows that the in-situ generation of a two-dimensional shell layer at the FAPbI3 grain boundary is effective in improving device performance. Comparing Examples 1 and 2, when a three-dimensional two-dimensional core-shell self-encapsulated perovskite light-absorbing layer is used, the device performance reaches the optimal value, with the photoelectric conversion efficiency improving by 5% to 20%, and the long-term stability is fundamentally improved. This verifies the significant effect of the three-dimensional two-dimensional core-shell self-encapsulated perovskite light-absorbing layer of the present invention on improving device performance and long-term stability, providing key technical support for the industrialization of perovskite solar cells.

[0070] The above embodiments and accompanying drawings are not intended to limit the product form and preparation method of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A three-dimensional / two-dimensional core-shell self-encapsulated inverted perovskite solar cell, characterized in that: It includes a conductive glass conductive layer, a hole transport layer, a FAPbI3 three-dimensional two-dimensional core-shell self-encapsulating perovskite light absorption layer, an electron transport layer, and an AZO electrode layer arranged sequentially, wherein the hole transport layer is stacked on the conductive glass conductive layer; A PbI2 layer for two-step preparation of FAPbI3 layer is formed on the hole transport layer. The PbI2 layer is an intermediate for generating FAPbI3 layer. The PbI2 layer is prepared by coating the hole transport layer with PbI2 solution. The hole transport layer, the PbI2 layer, and the electron transport layer all introduce organic macrocations for generating two-dimensional titanium ore, and the source of the organic macrocations is a pyridylamine derivative hydrohalate; the electron transport layer is formed on the FAPbI3 layer, and the AZO electrode layer is sputtered on the electron transport layer; During the preparation of the FAPbI3 three-dimensional two-dimensional core-shell self-encapsulated perovskite light absorption layer, two-dimensional perovskites are simultaneously generated at the interface between the FAPbI3 layer and the hole transport layer, at the interface between the FAPbI3 layer and the electron transport layer, and at each grain boundary within the FAPbI3 layer, thus forming the FAPbI3 three-dimensional two-dimensional core-shell self-encapsulated perovskite light absorption layer. The thickness of the FAPbI3 three-dimensional two-dimensional core-shell self-encapsulated perovskite light-absorbing layer is 500~800 nm. With FAPbI3 three-dimensional perovskite as the core, the residual PbI2 is reacted with or replaced by the pyridylamine derivative hydrohalate at its grain boundaries and at the interfaces with the hole transport layer and the electron transport layer, respectively. + Ions generate a two-dimensional perovskite shell.

2. The three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell according to claim 1, characterized in that: The hole transport layer has a thickness of 15-25 nm and is prepared using NiO nanocrystals with a particle size of 3-5 nm. The hole transport layer is a NiO nanocrystal hole transport layer. The electron transport layer has a thickness of 15-30 nm and is prepared using SnO2 nanorods with a particle size of 2-4 nm and an aspect ratio of 3-5. The electron transport layer is a SnO2 nanorod electron transport layer. The AZO electrode layer is an aluminum-doped zinc oxide top electrode. The hole transport layer has a planar structure. The electron transport layer has a planar structure.

3. The three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell according to claim 2, characterized in that: The pyridylamine derivative hydrohalate is attached to the surface of NiO nanocrystals and SnO2 nanorods through ligand exchange. In preparing the PbI2 layer, a pyridylamine derivative hydrohalate is added to the PbI2 solution.

4. The three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell as described in claim 1, characterized in that: The pyridylamine derivative hydrohalate is a compound whose molecular structure contains both a pyridine ring and an amino group and forms a salt with a hydrohalic acid. The amino group is -NH2, -NHR, or -NR2, and R is an alkyl, aryl, or other non-hydrogen organic substituent. The hydrohalic acid includes HCl, HBr, HI, or HF.

5. The three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell as described in claim 4, characterized in that: The pyridylamine derivative hydrohalate is 4-formamidinylpyridine dihydrochloride, 2-formamidinylpyridine hydrochloride, 2-(2-pyridyl)ethylamine hydroiodate, 3-pyridineethylamine hydroiodate, or 2-pyridinemethylamine hydrochloride.

6. A method for fabricating a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell according to any one of claims 1 to 5, characterized in that: Includes the following steps: Step 1: Disperse NiO nanocrystals with an oleylamine ligand and a particle size of 3-5 nm in n-hexane to prepare a NiO nanocrystal dispersion with a concentration of 2-8 mg / mL. The dispersion was spin-coated onto the conductive layer of conductive glass in two steps. First, the dispersion was spin-coated at 400-800 rpm for 3-5 seconds to allow it to spread and wet the conductive layer. Then, the dispersion was spin-coated at 3000-5000 rpm for 30-60 seconds to control the thickness of the NiO nanocrystalline particle layer. The NiO nanocrystal layer was placed in an N,N-dimethylformamide solution containing a mixture of NOBF4 and pyridylamine derivative hydrohalides at 40-60°C for 6-12 hours to fully complete ligand exchange. The concentration of NOBF4 was 10-25 mg / mL, and the concentration of pyridylamine derivative hydrohalides was 2.5-6 mg / mL. The strong oxidizing nitrosamine cations underwent electrophilic addition and oxidation with oleylamine to generate non-coordinating nitrosamines, which desorbed from the surface of the NiO nanocrystals. The NiO nanocrystal particles spontaneously and tightly bound together and adsorbed the pyridylamine derivative hydrohalides to form a hole transport layer with a thickness of 15-25 nm. After rinsing with anhydrous ethanol, the layer was dried by heating at 50-100°C for 15-30 minutes. Step 2: Disperse SnO2 nanorods with a particle size of 2-4 nm, an aspect ratio of 3-5, and containing oleylamine ligands in toluene to prepare a SnO2 nanorod toluene dispersion with a concentration of 10-50 mg / mL; dissolve NOBF4 and pyridylamine derivative hydrohalide in N,N-dimethylformamide to prepare a mixed solution, so that the concentrations of NOBF4 and pyridylamine derivative hydrohalide are 5-12 mg / mL and 2.5-6 mg / mL, respectively. Under magnetic stirring at 500-1000 rpm, a N,N-dimethylformamide solution containing 1-4 times the volume of NOBF4 and pyridylamine derivative hydrohalide salts was added dropwise to the SnO2 nanorod toluene dispersion. The mixture was stirred continuously for 0.5-2 hours to completely transfer the SnO2 nanorods from the upper toluene solution to the lower N,N-dimethylformamide solution, thus completing the ligand exchange. Collect the lower layer solution, add 2 to 5 times its volume of acetone to precipitate the SnO2 nanorods, and centrifuge at 6000 to 10000 rpm for 15 to 30 minutes, and collect the centrifuged material. The centrifuged material was ultrasonically dispersed in isopropanol at 150-180W to prepare an isopropanol dispersion of SnO2 nanorods containing pyridylamine derivative hydrohalate ligands at a concentration of 2-8 mg / mL. Step 3: Prepare a solution of N,N-dimethylformamide and dimethyl sulfoxide with a concentration of 1.2~1.5 M PbI2, with a volume ratio of N,N-dimethylformamide to dimethyl sulfoxide of 4:1~9:

1. Then add pyridinylamine derivative hydrohalate to the solution, with a concentration of 2~10 mg / mL. Continue spin-coating the solution onto the planar hole transport layer prepared in step 1. Use a two-step spin-coating process: first spin-coat at 400-800 rpm for 5-10 s to allow the PbI2 solution to fully spread and wet the hole transport layer; then spin-coat at 1000-3000 rpm for 30-60 s to control the thickness of the PbI2 layer; and finally anneal at 50-100℃ for 15-30 minutes. Step 4: Prepare isopropanol mixed solutions of formamidin hydroiodide and methylamine hydrochloride with concentrations of 0.6~1.0 M and 0.02~0.08 M, respectively; After the PbI2 layer prepared in step 3 has cooled to room temperature, a mixed solution of formamidinium hydroiodide and methylamine hydrochloride in isopropanol is spin-coated. The spin-coating is done in two steps: first, spin-coat at 400-800 rpm for 10-30 s to allow the mixed solution of formamidinium hydroiodide and methylamine hydrochloride in isopropanol to fully spread and wet the PbI2 layer; then spin-coat at 2000-5000 rpm for 30-60 s to allow the PbI2 to fully react with the formamidinium hydroiodide and methylamine hydrochloride to form an FAPbI3 layer. Continue spin-coating the isopropanol dispersion of SnO2 nanorods containing pyridylamine derivative hydrohalate ligands prepared in step 2. Use a two-step spin-coating method: first spin-coat at 400-800 rpm for 5-10 s to allow the dispersion to fully spread and wet the FAPbI3 layer, and then spin-coat at 3000-5000 rpm for 30-60 s to control the thickness of the SnO2 nanorod layer to be 15-30 nm. Step 5: Anneal the sample prepared in Step 4 at 150-170 °C for 30-60 minutes to generate a three-dimensional perovskite with FAPbI3 as the core. At its grain boundaries and interfaces with the hole transport layer and electron transport layer, the residual PbI2 is reacted with or replaced by pyridylamine derivative hydrohalates. + A three-dimensional two-dimensional core-shell self-encapsulated perovskite light-absorbing layer with a thickness of 500~800 nm is generated by ion-generated two-dimensional perovskite shell. Finally, an AZO top electrode is sputtered onto the electron transport layer to obtain a three-dimensional two-dimensional core-shell self-encapsulated inverted perovskite solar cell.

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