Trans-perovskite solar cell and preparation method thereof
By introducing N-nitroso-N-methylurethane additive into inverted perovskite solar cells, the problems of uneven grain size and high defect density of the perovskite active layer were solved, thereby improving photoelectric conversion efficiency and enhancing long-term stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-30
- Publication Date
- 2026-05-01
AI Technical Summary
The performance of inverted perovskite solar cells is limited by the non-uniform grain size and high internal defect density of the perovskite active layer, which leads to an increased carrier recombination probability, reduced photoelectric conversion efficiency, and easy decomposition under harsh environments, affecting long-term stability.
By introducing N-nitroso-N-methylurethane as an additive, it forms stable coordination with perovskite defect sites, regulates the crystallization process, reduces internal defects in the thin film, and improves photoelectric conversion efficiency and stability.
It significantly improves photoelectric conversion efficiency, enhances the chemical stability of the perovskite lattice, suppresses decomposition and phase transition under light and humidity conditions, and extends the long-term working stability of the battery.
Smart Images
Figure CN121968880A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of solar cell technology, specifically relating to an inverted perovskite solar cell and its preparation method. Background Technology
[0002] Perovskite solar cells have attracted widespread attention due to their excellent photoelectric performance. Among them, inverted perovskite cells, with their good structural symmetry and reasonable carrier transport path, show broad application prospects in the fields of flexible devices and tandem cells.
[0003] However, the performance of inverted perovskite solar cells is still limited by the quality of the perovskite active layer. During the fabrication process, the perovskite active layer is prone to problems such as uneven grain size and high internal defect density. These defects become non-radiative recombination centers, increasing the probability of carrier recombination and thus reducing the cell's photoelectric conversion efficiency. Simultaneously, these defects are also the main causes of decomposition and performance degradation of perovskite materials under environmental factors such as light and humidity, impairing the long-term operational stability of the cell.
[0004] To improve the quality of the perovskite active layer, existing technologies typically employ the introduction of additives into the perovskite precursor solution to regulate the perovskite crystallization process, passivate defects, and enhance stability. For example, organic molecules such as glycine hydrochloride and urea are used as additives to control the perovskite crystallization process through intermolecular interactions, thereby improving the quality of the perovskite film. However, these additives usually rely on weak intermolecular hydrogen bonding interactions, and their passivation effect is prone to failure under harsh environmental conditions such as high temperature and high humidity, resulting in limited improvement in battery efficiency and stability. Summary of the Invention
[0005] To overcome the technical problems of existing additives relying on weak hydrogen bonding interactions and easily failing in passivation under harsh environments, this invention provides an inverted perovskite solar cell and its preparation method. By introducing N-nitroso-N-methylurethane as an additive, this invention can form stable coordination with perovskite defect sites, thereby effectively controlling the perovskite crystallization process, reducing internal defects in the thin film, and simultaneously improving the photoelectric conversion efficiency and long-term environmental stability of the inverted perovskite solar cell.
[0006] The first objective of this invention is to provide an inverted perovskite solar cell, comprising a substrate and a transparent conductive layer, a hole transport layer, a perovskite active layer, an electron transport layer, and a metal electrode layer sequentially stacked on the substrate. The perovskite active layer is formed by depositing and crystallizing a lead-based perovskite precursor solution containing the additive on the hole transport layer using N-nitroso-N-methylurethane as an additive. The nitroso and urethane groups in the N-nitroso-N-methylurethane molecule react with the Pb in the lead-based perovskite precursor. 2+ and I- Formation of complexes.
[0007] Preferably, the lead-based perovskite precursor is formamidinium lead-iodide perovskite, formamidinium cesium lead-iodide perovskite, or formamidinium methylamine lead-iodide perovskite; the thickness of the perovskite active layer is 300 nm to 600 nm. The perovskite active layer has excellent light absorption and carrier transport properties, and is the core functional layer of the perovskite solar cell.
[0008] Preferably, the hole transport layer is made of nickel oxide, cobalt oxide, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, or poly(3,4-ethylenedioxythiophene)poly(styrene sulfonate); the thickness of the hole transport layer is 10 nm to 50 nm. The hole transport layer can efficiently extract holes generated in the perovskite active layer and suppress electron-hole pair recombination.
[0009] Preferably, the electron transport layer is made of at least one of C60, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, methyl [6,6]-phenyl-C61-butyrate, methyl [6,6]-phenyl-C71-butyrate, and zinc oxide; the thickness of the electron transport layer is 20 nm to 80 nm. The electron transport layer can effectively extract electrons from the perovskite active layer and prevent holes from migrating to the metal electrode.
[0010] Preferably, the transparent conductive layer is a fluorine-doped tin oxide layer, an indium-doped tin oxide layer, or an aluminum-doped zinc oxide layer; the thickness of the transparent conductive layer is 80 nm to 200 nm. The transparent conductive layer has high conductivity and high light transmittance, which can effectively transport photogenerated carriers and allow sunlight to pass through.
[0011] Preferably, the metal electrode is a silver electrode, a gold electrode, or an aluminum electrode; the thickness of the metal electrode layer is 80 nm to 200 nm. The metal electrode has good conductivity and can output the collected charge carriers to form a current.
[0012] Preferably, the substrate is glass or a flexible polymer. Glass substrates have good rigidity and light transmittance, while flexible polymer substrates are suitable for fabricating flexible perovskite solar cells to meet the needs of different application scenarios.
[0013] A second objective of this invention is to provide a method for preparing an inverted perovskite solar cell, comprising the following steps: A transparent conductive layer and a hole transport layer are prepared on a substrate. A lead-based perovskite precursor and N-nitroso-N-methylurethane are dissolved in a solvent to obtain a lead-based perovskite precursor solution. The lead-based perovskite precursor solution is deposited on the hole transport layer, and after crystallization, the nitroso and urethane groups in the N-nitroso-N-methylurethane molecules react with the Pb in the lead-based perovskite precursor. 2+ and I -A complex is formed to obtain a perovskite active layer; an electron transport layer and a metal electrode layer are then formed sequentially on the perovskite active layer to obtain an inverted perovskite solar cell.
[0014] The preparation method of this invention is based on mature spin-coating, annealing, and thermal evaporation processes. The introduction of N-nitroso-N-methylurethane as an additive does not change the original process flow; it only needs to be added when preparing the precursor solution. This method is simple to operate, low in cost, requires no complex equipment, and has good process compatibility and potential for large-scale production.
[0015] Preferably, the mass concentration of N-nitroso-N-methylurethane in the lead-based perovskite precursor solution is 1 mg / mL to 1.5 mg / mL.
[0016] Preferably, the crystallization treatment is performed by annealing at 100℃~130℃ for 15 minutes to 30 minutes.
[0017] Preferably, the lead-based perovskite precursor has the chemical formula Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3; where FA represents formamidin cation and MA represents methylammonium ion.
[0018] Preferably, during the deposition of the precursor solution, an antisolvent is added dropwise, wherein the antisolvent is selected from chlorobenzene, toluene, or diethyl ether.
[0019] Compared with the prior art, the present invention has the following technical effects: This invention, by introducing N-nitroso-N-methylurethane, effectively regulates the nucleation and growth process of perovskite crystals, promoting the formation of large-sized, highly crystalline perovskite grains, reducing carrier recombination at grain boundaries, and improving the crystallinity and uniformity of the film. Simultaneously, the nitroso and urethane groups in the N-nitroso-N-methylurethane molecule can react with Pb in the perovskite lattice. 2+ and I - Strong and stable coordination complexes at defect sites enable effective defect passivation. These two factors work together to significantly reduce non-radiative recombination losses of charge carriers within the perovskite layer, thereby substantially improving the photoelectric conversion efficiency and stability of the battery.
[0020] This invention utilizes the stable bonding of N-nitroso-N-methylurethane additives with perovskite defect sites, which not only passivates electrically active defects but also enhances the chemical stability of the perovskite lattice interface. This effectively suppresses the decomposition and phase transition of perovskite under light and humidity conditions, thereby significantly improving the long-term operational stability of the battery. Attached Figure Description
[0021] Figure 1 The JV curves are for the inverted perovskite solar cells prepared in Examples 1-2 and Comparative Example 1. Detailed Implementation
[0022] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings.
[0023] Unless otherwise specified, all reagents used in this invention are commercially available, and all methods used are conventional techniques in the art.
[0024] The Chinese name of MeO-2PACz is [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, and the Chinese name of BCP is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.
[0025] Example 1 A method for fabricating an inverted perovskite solar cell includes the following steps: The glass substrate was sequentially placed in an ultrasonic cleaner containing deionized water, acetone, and isopropanol for 20 minutes each to remove surface organic matter and particulate contaminants. After cleaning, the substrate surface was dried with high-purity nitrogen gas, and then placed in a UV ozone cleaner for 10 minutes to improve the hydrophilicity of the glass substrate surface and enhance the adhesion between the subsequent functional layers and the glass substrate.
[0026] A transparent conductive layer was obtained by forming a 400 nm fluorine-doped tin oxide layer on the surface of a cleaned glass substrate using magnetron sputtering.
[0027] MeO-2PACz was dissolved in anhydrous ethanol to obtain a 1 mmol / L solution. This solution was then spin-coated onto a transparent conductive layer using a spin coater at 3000 rpm for 20 seconds. Subsequently, the layer was annealed at 100°C for 10 minutes to obtain a hole transport layer with a thickness of 50 nm.
[0028] According to the chemical formula Cs 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.953. Weigh the raw materials and dissolve PbI2, MABr, PbBr2, FAI, CsI and N-nitroso-N-methylurethane in N,N-dimethylformamide and dimethyl sulfoxide to obtain a lead-based perovskite precursor solution; the mass concentration of N-nitroso-N-methylurethane in the lead-based perovskite precursor solution is 1.0 mg / mL, and the volume ratio of N,N-dimethylformamide and dimethyl sulfoxide is 4:1.
[0029] In a glove box, a lead-based perovskite precursor solution was spin-coated onto the surface of the hole transport layer at a spin speed of 3000 rpm for 20 s. Before the end of the spin coating, chlorobenzene was added as an anti-solvent to promote rapid crystallization of the perovskite. Then, the perovskite was annealed at 120 °C for 20 min to allow it to fully crystallize and form a high-quality perovskite active layer.
[0030] An electron transport layer was obtained by sequentially depositing a 25 nm thick C60 layer and a 6 nm thick BCP layer on the perovskite active layer using vacuum thermal evaporation.
[0031] An inverted perovskite solar cell was obtained by depositing an 80 nm thick silver electrode in the electron transport layer using a thermal evaporation process.
[0032] Example 2 A method for fabricating an inverted perovskite solar cell includes the following steps: The difference from Example 1 is as follows: The mass concentration of N-nitroso-N-methylurethane in the lead-based perovskite precursor solution was 1.5 mg / mL.
[0033] The glass substrate was sequentially placed in an ultrasonic cleaner containing deionized water, acetone, and isopropanol for 20 minutes each to remove surface organic matter and particulate contaminants. After cleaning, the substrate surface was dried with high-purity nitrogen gas, and then placed in a UV ozone cleaner for 10 minutes to improve the hydrophilicity of the glass substrate surface and enhance the adhesion between the subsequent functional layers and the glass substrate.
[0034] A transparent conductive layer was obtained by forming a 400 nm fluorine-doped tin oxide layer on the surface of a cleaned glass substrate using magnetron sputtering.
[0035] MeO-2PACz was dissolved in anhydrous ethanol to obtain a 1 mmol / L solution. This solution was then spin-coated onto a transparent conductive layer using a spin coater at 3000 rpm for 20 seconds. Subsequently, the layer was annealed at 100°C for 10 minutes to obtain a hole transport layer with a thickness of 50 nm.
[0036] According to the chemical formula Cs 0.05 (MA 0.05 FA 0.95 )0.95 Pb(Br 0.05 I 0.95 3. Weigh the raw materials and dissolve PbI2, MABr, PbBr2, FAI, CsI and N-nitroso-N-methylurethane in N,N-dimethylformamide and dimethyl sulfoxide to obtain a lead-based perovskite precursor solution; the mass concentration of N-nitroso-N-methylurethane in the lead-based perovskite precursor solution is 1.5 mg / mL, and the volume ratio of N,N-dimethylformamide and dimethyl sulfoxide is 4:1.
[0037] In a glove box, a lead-based perovskite precursor solution was spin-coated onto the surface of the hole transport layer at a spin speed of 3000 rpm for 20 s. Before the end of the spin coating, chlorobenzene was added as an anti-solvent to promote rapid crystallization of the perovskite. Then, the perovskite was annealed at 120 °C for 20 min to allow it to fully crystallize and form a high-quality perovskite active layer.
[0038] An electron transport layer was obtained by sequentially depositing a 25 nm thick C60 layer and a 6 nm thick BCP layer on the perovskite active layer using vacuum thermal evaporation.
[0039] An inverted perovskite solar cell was obtained by depositing an 80 nm thick silver electrode in the electron transport layer using a thermal evaporation process.
[0040] Comparative Example 1 A method for fabricating an inverted perovskite solar cell includes the following steps: The difference from Example 1 is as follows: The lead-based perovskite precursor solution was not supplemented with N-nitroso-N-methylurethane.
[0041] The glass substrate was sequentially placed in an ultrasonic cleaner containing deionized water, acetone, and isopropanol for 20 minutes each to remove surface organic matter and particulate contaminants. After cleaning, the substrate surface was dried with high-purity nitrogen gas, and then placed in a UV ozone cleaner for 10 minutes to improve the hydrophilicity of the glass substrate surface and enhance the adhesion between the subsequent functional layers and the glass substrate.
[0042] A transparent conductive layer was obtained by forming a 400 nm fluorine-doped tin oxide layer on the surface of a cleaned glass substrate using magnetron sputtering.
[0043] MeO-2PACz was dissolved in anhydrous ethanol to obtain a 1 mmol / L solution. This solution was then spin-coated onto a transparent conductive layer using a spin coater at 3000 rpm for 20 seconds. Subsequently, the layer was annealed at 100°C for 10 minutes to obtain a hole transport layer with a thickness of 50 nm.
[0044] According to the chemical formula Cs 0.05 (MA0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 3. Weigh the raw materials and dissolve PbI2, MABr, PbBr2, FAI, CsI, and N-nitroso-N-methylurethane in N,N-dimethylformamide and dimethyl sulfoxide to obtain a lead-based perovskite precursor solution. In a glove box, spin-coat the lead-based perovskite precursor solution onto the surface of the hole transport layer at a spin speed of 3000 rpm for 20 s. Before the end of the spin coating, add chlorobenzene as an anti-solvent to promote rapid crystallization of the perovskite. Then anneal at 120℃ for 20 min to allow the perovskite to fully crystallize and form a high-quality perovskite active layer.
[0045] An electron transport layer was obtained by sequentially depositing a 25 nm thick C60 layer and a 6 nm thick BCP layer on the perovskite active layer using vacuum thermal evaporation.
[0046] An inverted perovskite solar cell was obtained by depositing an 80 nm thick silver electrode in the electron transport layer using a thermal evaporation process.
[0047] Test 1.
[0048] The performance of the inverted perovskite solar cells prepared in Examples 1, 2, and Comparative Example 1 was tested. The JV characteristic curves of the cells were measured using a standard solar simulator and a digital source meter. The results are as follows: Figure 1 As shown in Table 1, the test data is summarized as follows:
[0049] Table 1. Electrical performance data of the inverted perovskite solar cells prepared in Examples 1-2 and Comparative Example 1 The test results show that the addition of N-nitroso-N-methylurethane additive to the lead-based perovskite precursor solution significantly improves the photoelectric conversion efficiency of inverted perovskite solar cells. In particular, when the N-nitroso-N-methylurethane concentration is 1.0 mg / mL, the inverted perovskite solar cell achieves the best overall performance: both open-circuit voltage and short-circuit current density are significantly improved, the fill factor is also improved, and the final photoelectric conversion efficiency reaches 25.33%, an improvement of approximately 12.3% compared to the control group without N-nitroso-N-methylurethane. This demonstrates the positive role of N-nitroso-N-methylurethane additive in optimizing perovskite film quality and reducing defect recombination.
[0050] Experimental results show that after 1000 hours of storage under standard illumination and 50% relative humidity, the photoelectric conversion efficiency of the inverted perovskite solar cell prepared in Example 1 can still maintain more than 90% of the initial efficiency.
[0051] It should be noted that when numerical ranges are involved in this invention, it should be understood that the two endpoints of each numerical range, as well as any value between the two endpoints, can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described in this invention to avoid redundancy. Although preferred embodiments of this invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments, and all such changes and modifications fall within the scope of this invention.
[0052] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. If these modifications and variations fall within the scope of equivalents of this invention, then this invention also intends to include these modifications and variations.
Claims
1. A reverse perovskite solar cell, comprising a substrate and a transparent conductive layer, a hole transport layer, a perovskite active layer, an electron transport layer, and a metal electrode layer sequentially stacked on the substrate, characterized in that, The perovskite active layer is formed by depositing and crystallizing a lead-based perovskite precursor solution containing N-nitroso-N-methylurethane on a hole transport layer, using N-nitroso-N-methylurethane as an additive. The nitroso and urethane groups in the N-nitroso-N-methylurethane molecule react with the Pb in the lead-based perovskite precursor. 2+ and I - Formation of complexes.
2. The inverted perovskite solar cell according to claim 1, characterized in that, Lead-based perovskite precursors are formamidinium lead-iodide perovskite, formamidinium cesium lead-iodide perovskite, or formamidinium methylamine lead-iodide perovskite.
3. The inverted perovskite solar cell according to claim 1, characterized in that, The thickness of the perovskite active layer is 300 nm to 600 nm.
4. The inverted perovskite solar cell according to claim 1, characterized in that, The hole transport layer is made of nickel oxide, cobalt oxide, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, or poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate); the thickness of the hole transport layer is 10 nm to 50 nm.
5. The inverted perovskite solar cell according to claim 1, characterized in that, The electron transport layer is made of at least one of C60, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, methyl [6,6]-phenyl-C61-butyrate, methyl [6,6]-phenyl-C71-butyrate, and zinc oxide; the thickness of the electron transport layer is 20 nm to 80 nm.
6. The inverted perovskite solar cell according to claim 1, characterized in that, The transparent conductive layer is a fluorine-doped tin oxide layer, an indium-doped tin oxide layer, or an aluminum-doped zinc oxide layer; the thickness of the transparent conductive layer is 80 nm to 200 nm.
7. A method for preparing an inverted perovskite solar cell according to any one of claims 1 to 6, characterized in that, Includes the following steps: A transparent conductive layer and a hole transport layer are fabricated on a substrate; A lead-based perovskite precursor and N-nitroso-N-methylurethane were dissolved in a solvent to obtain a lead-based perovskite precursor solution. A lead-based perovskite precursor solution was deposited on a hole transport layer, followed by crystallization. The nitroso and urethane groups in the N-nitroso-N-methylurethane molecule reacted with the Pb in the lead-based perovskite. 2+ and I - A complex is formed, resulting in a perovskite active layer; An electron transport layer and a metal electrode layer are sequentially formed on the perovskite active layer to obtain an inverted perovskite solar cell.
8. The method for preparing an inverted perovskite solar cell according to claim 7, characterized in that, The mass concentration of N-nitroso-N-methylurethane in the lead-based perovskite precursor solution is 1 mg / mL to 1.5 mg / mL.
9. The method for preparing an inverted perovskite solar cell according to claim 7, characterized in that, The crystallization process involves annealing at 100℃~130℃ for 15 to 30 minutes.
10. The method for preparing an inverted perovskite solar cell according to claim 7, characterized in that, The chemical formula of the lead-based perovskite precursor is Cs 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3; where FA represents formamidin cation and MA represents methylammonium ion.