Perovskite solar cell and method for increasing reverse breakdown voltage thereof
By setting up a dielectric protective layer in a perovskite solar cell and modifying it with a highly negative charge strongly polar organic small molecule solution, the problem of reverse bias voltage of perovskite solar cells in a shadow state is solved, and the reverse breakdown voltage and efficiency of the battery are significantly improved.
Patent Information
- Application Number
- CN202510348655.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-24
- Publication Date
- 2025-06-27
AI Technical Summary
Perovskite solar cells are susceptible to the impact of reverse bias voltage in the shadow state, resulting in performance damage and even irreversible damage. The prior art protects them by adding reverse diodes, but there are problems of energy loss and high cost.
A dielectric protective layer is provided between the hole transport layer of a perovskite solar cell and the perovskite light absorbing layer, and a dielectric protective layer made of a highly polar organic small molecule solution with high negative charge is prepared by a spin coating process.
It effectively improves the reverse breakdown voltage of perovskite solar cells, reduces the damage to battery performance by the reverse bias voltage, and improves the battery efficiency and operating stability.
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Figure CN120225015A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of solar cells, and in particular relates to a perovskite solar cell and a method for increasing its reverse breakdown voltage. Background Art
[0002] In recent years, perovskite solar cells have attracted much attention from academia and industry. Compared with traditional silicon-based solar cells, perovskite solar cells have lower costs and are expected to replace silicon-based solar cells in commercial applications. And with the continuous breakthroughs in battery technology, its photoelectric conversion efficiency is comparable to that of commercial silicon-based solar cells.
[0003] However, in the actual operation of solar cells, due to snow, leaves and other obstructions, some cells are in the shade state, resulting in them being connected in series in the circuit as a load, causing them to be subjected to reverse bias voltage. When the reverse bias voltage reaches a certain value, it will seriously affect the performance of the solar cell and even cause irreversible damage. Among them, the reverse bias voltage threshold that begins to damage the cell is defined as the reverse breakdown voltage of the cell. Generally, the reverse breakdown voltage of perovskite solar cells is low, and irreversible damage and breakdown will occur when a voltage of -2 V is applied. In order to reduce or even avoid the damage of reverse bias voltage to cell performance, a reverse diode can be connected in parallel to a single-junction solar cell. In this way, when the cell is in the shade and subjected to a directional bias voltage, the current will preferentially pass through the diode, thereby achieving the protection of the cell. Unfortunately, adding a bypass diode will result in a certain amount of energy loss, and its own voltage resistance performance is limited, the cost is high, and the process is complicated. Summary of the invention
[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a perovskite solar cell and a method for improving its reverse breakdown voltage. The present invention can improve the reverse breakdown voltage of the perovskite solar cell, thereby reducing or even avoiding the damage to the battery performance caused by the reverse bias voltage.
[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A method for increasing the reverse breakdown voltage of a perovskite solar cell comprises the following steps: A dielectric protective layer is arranged between the hole transport layer and the perovskite light absorbing layer of the perovskite solar cell. The dielectric protective layer is prepared on the surface of the hole transport layer by a spin coating process. The solution used to prepare the dielectric protective layer is a solution made of a polar solvent and organic small molecules with strong polar groups. The strong polar groups include at least one of a nitro group, a sulfonic acid group, a cyano group and a fluorine group.
[0006] Preferably, in the solution for preparing the dielectric protection layer, the concentration of the organic small molecule is 1.9 to 2.1 mg / ml.
[0007] Preferably, the organic small molecule is at least one of dichloro(4-fluorophenyl)phosphine, fluoronaphthalene, 2,3-dicyanonaphthalene, 2,3-dicyanothiophene, pyridine p-toluenesulfonate, and 5-fluorouracil.
[0008] Preferably, the polar solvent is isopropyl alcohol.
[0009] Preferably, the process of preparing the dielectric protection layer on the surface of the hole transport layer by spin coating includes: Spin coating the solution for preparing the dielectric protection layer on the hole transport layer at 4950 to 5050 r / s in a protective atmosphere. After spin coating is completed, anneal at 95 to 105 °C for 9 to 11 minutes to form the dielectric protection layer.
[0010] Preferably, the method for improving the reverse breakdown voltage of the perovskite solar cell in the present invention further includes the following process: Prepare a hole transport layer on the surface of the transparent electrode layer, prepare a dielectric protection layer on the surface of the hole transport layer, prepare a perovskite light absorption layer on the surface of the dielectric protection layer, and then sequentially prepare an interface passivation layer, an electron transport layer, a hole blocking layer, and an electrode on the surface of the perovskite light absorption layer.
[0011] Preferably, the transparent electrode layer is fluorine-doped indium tin oxide conductive glass or indium tin oxide conductive glass.
[0012] Preferably, the process of preparing the hole transport layer on the surface of the transparent electrode layer includes: Spin coat a deionized water dispersion of nano nickel oxide with a concentration of 9 to 11 mg / ml on the surface of the transparent electrode layer at 1950 to 2050 r / s, and then anneal at 145 to 155 °C for 9 to 11 minutes to obtain film A; Spin coat an absolute ethanol dispersion of [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid with a concentration of 0.4 to 0.6 mg / ml on the surface of film A at 3950 to 4050 r / s, and then anneal at 95 to 105 °C for 9 to 11 minutes to obtain film B; Film A and film B constitute the hole transport layer.
[0013] Preferably: The process of preparing the interface passivation layer on the surface of the perovskite light absorption layer includes: Spin coat an isopropyl alcohol solution of 1,3-diaminopropane dihydroiodide with a concentration of 0.9 to 1.1 mg / ml on the surface of the perovskite light absorption layer at 4950 to 5050 r / s in a protective atmosphere, and then anneal at 95 to 105 °C for 9 to 11 minutes to obtain the interface passivation layer; C60, bathocuproine, and silver are sequentially evaporated on the surface of the interface passivation layer to form an electron transport layer, a hole blocking layer, and an electrode in sequence; wherein, the thicknesses of the electron transport layer, the hole blocking layer, and the electrode are 245 - 255 nm, 55 - 65 nm, and 1095 - 1105 nm, respectively.
[0014] The present invention also provides a perovskite solar cell obtained by the method for improving the reverse breakdown voltage of a perovskite solar cell as described above in the present invention.
[0015] Compared with the prior art, this patent has the following advantages: The method for improving the reverse breakdown voltage of a perovskite solar cell in the present invention is to use strongly polar organic small molecules with high electronegativity and prepare a dielectric protection layer by a spin coating process, and this dielectric protection layer is located between the hole transport layer and the perovskite light absorption layer of the perovskite solar cell. Such organic small molecules can effectively passivate defects such as uncoordinated lead at the bottom of the perovskite, and the fluorine units with high electronegativity contained therein can make up for the halogen vacancies in the perovskite and regulate the crystallization of the perovskite. More importantly, while modifying the bottom of the perovskite, the reverse breakdown voltage of the perovskite solar cell is increased, and the efficiency and operating stability of the perovskite solar cell are improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a comparison of the reverse breakdown voltage values of the unpassivated (Control) and passivated (Target) perovskite solar cells in Example 1 of the present invention.
[0017] Figure 2 It is a comparison of the efficiencies of the unpassivated (Control) and passivated (Target) perovskite solar cells in Example 1 of the present invention.
[0018] Figure 3 It is a comparison of the reverse breakdown voltage values of the unpassivated (Control) and passivated (Target) perovskite solar cells in Example 2 of the present invention.
[0019] Figure 4 It is a comparison of the efficiencies of the unpassivated (Control) and passivated (Target) perovskite solar cells in Example 2 of the present invention.
[0020] Figure 5 It is a comparison of the reverse breakdown voltage values of the unpassivated (Control) and passivated (Target) perovskite solar cells in Example 3 of the present invention.
[0021] Figure 6Efficiency comparison of the perovskite solar cells without passivation (Control) and after passivation (Target) in Example 3 of the present invention.
[0022] Figure 7 Reverse breakdown voltage value comparison of the perovskite solar cells without passivation (Control) and after passivation (Target) in Example 4 of the present invention.
[0023] Figure 8 Efficiency comparison of the perovskite solar cells without passivation (Control) and after passivation (Target) in Example 4 of the present invention.
[0024] Figure 9 Reverse breakdown voltage value comparison of the perovskite solar cells without passivation (Control) and after passivation (Target) in Example 5 of the present invention.
[0025] Figure 10 Efficiency comparison of the perovskite solar cells without passivation (Control) and after passivation (Target) in Example 5 of the present invention.
[0026] Figure 11 Reverse breakdown voltage value comparison of the perovskite solar cells without passivation (Control) and after passivation (Target) in Example 6 of the present invention.
[0027] Figure 12 Efficiency comparison of the perovskite solar cells without passivation (Control) and after passivation (Target) in Example 6 of the present invention. Detailed implementation manners
[0028] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as a limitation to the present application. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.
[0029] In this application, when it comes to numerical intervals (i.e., numerical ranges), unless otherwise specified, the distribution of the selectable numerical values within the numerical interval is considered continuous, and includes the two numerical endpoints (i.e., the minimum value and the maximum value) of the numerical interval, as well as each numerical value between these two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers within the numerical interval, it includes the two endpoint integers of the numerical range, as well as each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all sub-ranges subsumed therein. The "numerical values" in the numerical interval can be any quantitative values, such as numbers, percentages, ratios, etc. The "numerical interval" is allowed to broadly include quantitative intervals such as percentage intervals, ratio intervals, ratio value intervals, etc.
[0030] The main idea of the method for improving the reverse breakdown voltage of perovskite solar cells in the present invention is as follows: First, screen out organic small molecules with strong polar groups as the selection targets. The strong polar groups of organic small molecules are: nitro group, sulfonic acid group, cyano group, fluoro group. Therefore, organic small molecules containing single or multiple strong polar groups can be specifically selected to act as the dielectric protection layer, such as dichloro(4-fluorophenyl)phosphine, fluoronaphthalene, 2,3-dicyanonaphthalene, 2,3-dicyanothiophene, pyridinium p-toluenesulfonate, 5-fluorouracil and other organic small molecules.
[0031] Secondly, dissolve the selected organic small molecules in a polar solvent at a certain concentration for standby. Subsequently, clean the fluorine-doped indium tin oxide conductive glass (FTO), and perform surface treatment using an ultraviolet ozone instrument. Use nickel oxide (NiOx) and [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACZ) as the hole transport layer of the perovskite solar cell and spin-coat them on the FTO respectively. The dielectric protection layer is obtained by spin-coating the prepared organic small molecule solution on the hole transport layer and annealing for shaping. The perovskite light-absorbing layer is prepared by a traditional spin-coating process, and 1,3-diaminopropane dihydroiodide (PDAI2) is used as the interface passivation layer and spin-coated on the perovskite thin film. Finally, evaporate the electron transport layer, hole blocking layer and electrodes in a vacuum coating machine to complete the preparation of the perovskite solar cell.
[0032] In the above scheme of the present invention, the strong polarity and high negative electronegativity of the organic interfacial molecules with strong polarity can endow the perovskite with a larger dielectric constant, thereby protecting the perovskite solar cell from reverse bias damage and improving the transient breakdown voltage and long-term reverse bias stability of the device. This strategy can greatly improve the practical application prospects of perovskite batteries.
[0033] As a preferred embodiment, the present invention provides the specific dosages of the above method as follows: (1) Disperse 10 ± 1 mg of nickel oxide nanoparticles in 1 ml of deionized water, and ultrasonically disperse at low temperature (0 °C) for 40 ± 1 min to obtain dispersion A. Filter the nickel oxide nanoparticle dispersion after ultrasonic treatment with a water-based filter. Spin-coat the filtered dispersion A on FTO at 2000 ± 50 r / s and anneal at 150 ± 5 °C for 10 ± 1 minutes to obtain film A.
[0034] (2) Disperse 1 ± 0.1 mg of Me-4PACz in 2 ml of absolute ethanol, and stir for 180 ± 1 min to obtain solution B. Spin-coat in a nitrogen environment glove box on film A at 4000 ± 50 r / s and anneal at 100 ± 5 °C for 10 ± 1 minutes to obtain film B.
[0035] (3) Disperse 2 ± 0.1 mg of organic small molecules in 1 ml of isopropanol, and stir for 180 ± 1 h to obtain solution C. Spin-coat in a nitrogen environment glove box on film B at 5000 ± 50 r / s and anneal at 100 ± 5 °C for 10 ± 1 minutes to obtain film C.
[0036] (4) Dissolve 13.5 mg of MACl, 20.78 mg of CsI, 22.25 mg of PbCl2, 261.39 mg of FAI, and 737.62 mg of PbI2 in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide (DMF:DMSO = 4:1 v%), stir for 6 h to obtain solution D. Filter the perovskite precursor solution with a polytetrafluoroethylene filter membrane before use, and spin-coat solution D on film C by a two-step method. First, spin-coat at 1000 ± 50 r / s for 10 s, then spin-coat at 5000 ± 50 r / s for 30 s, and add 150 μL of anisole when the countdown reaches 6 s, and anneal at 120 ± 5 °C for 20 ± 1 minutes to obtain film D.
[0037] (5) Dissolve 1 ± 0.1 mg of PDAI2 in 1 ml of isopropanol, and stir for 180 ± 1 min to obtain solution E. Spin-coat in a nitrogen environment glove box on film D at 5000 ± 50 r / s and anneal at 100 ± 5 °C for 10 ± 1 minutes to obtain film E.
[0038] (6) Evaporate C60, bathocuproine (BCP), and silver (Ag) on film E in a vacuum coating machine, with thicknesses of 250 ± 5 nm, 60 ± 5 nm, and 1100 ± 5 nm respectively, to complete the preparation of the perovskite solar cell device.
[0039] In the above solution, including but not limited to: for the dosage of components (such as mass), the value before the ± sign is the final nominal value, and the value after the ± sign is the deviation of the weighing equipment during weighing. For temperature, rotation speed, and time, the value before the ± sign is the set value, and the value after the ± sign is the equipment deviation value. In the following embodiments of the present invention, the corresponding parameters are described by taking the nominal value or the equipment set value as an example. It can be foreseen that within the corresponding deviation ranges of the relevant parameters, the technical solution of the present invention is feasible.
[0040] Example 1: The method for improving the reverse breakdown voltage of a perovskite solar cell in this embodiment includes the following steps: (1) Disperse 10 mg of nickel oxide nanoparticles in 1 ml of deionized water, and ultrasonically disperse them at a low temperature (0 °C) for 40 min to obtain a nickel oxide nanoparticle dispersion (denoted as dispersion A). Filter the nickel oxide nanoparticle dispersion after the ultrasonic treatment with a water-based filter. Spin-coat the filtered dispersion A on FTO at 2000 r / s and anneal it at 150 °C for 10 minutes to obtain film A.
[0041] (2) Disperse 1 mg of Me-4PACz in 2 ml of absolute ethanol, and stir for 3 h to obtain solution B. Spin-coat it on film A at 4000 r / s in a nitrogen-filled glove box and anneal it at 100 °C for 10 minutes to obtain film B.
[0042] (3) Disperse 2 mg of dichloro(4-fluorophenyl)phosphine in 1 ml of isopropanol, and stir for 3 h to obtain solution C. Spin-coat it on film B at 5000 r / s in a nitrogen-filled glove box and anneal it at 100 °C for 10 minutes to obtain film C.
[0043] (4) Dissolve 13.5 mg of MACl, 20.78 mg of CsI, 22.25 mg of PbCl2, 261.39 mg of FAI, and 737.62 mg of PbI2 in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide (DMF:DMSO = 4:1 v%), stir for 6 h to obtain solution D. Filter the perovskite precursor solution with a polytetrafluoroethylene filter membrane before use. Spin-coat solution D on film C by a two-step method, first spin-coat at 1000 r / s for 10 s, then spin-coat at 5000 r / s for 30 s, and add 150 μL of anisole at the 6th second of the countdown, and anneal at 120 °C for 20 minutes to obtain film D.
[0044] (5) Dissolve 1 mg of PDAI2 in 1 ml of isopropanol, and stir for 3 h to obtain solution E. Spin-coat it on film D at 5000 r / s in a nitrogen-filled glove box and anneal it at 100 °C for 10 minutes to obtain film E.
[0045] (6) Evaporate C60, bathocuproine (BCP), and silver (Ag) on the thin film E in a vacuum coating machine, with thicknesses of 250 nm, 60 nm, and 1100 nm respectively, to complete the preparation of the perovskite solar cell device.
[0046] As Figure 1 shown, for the device passivated with dichloro(4-fluorophenyl)phosphine, the breakdown voltage is increased from -0.91 V of the control sample to -5.22 V. And the efficiency of the relevant device ( Figure 2 shown) is also increased from 24.38% of the control sample ( J SC = 25.85 mA cm -2 ; V OC = 1.157 V; FF = 81.51%) to 26.13% ( J SC = 25.89 mA cm -2 ; V OC = 1.177 V; FF = 85.76%). It can be seen that dichloro(4-fluorophenyl)phosphine is very beneficial to improving the efficiency and reverse breakdown voltage of perovskite solar cells.
[0047] Example 2: The method for improving the reverse breakdown voltage of the perovskite solar cell in this example includes the following steps: (1) Disperse 10 mg of nickel oxide nanoparticles in 1 ml of deionized water, and ultrasonically disperse them at low temperature (0 °C) for 40 min to obtain dispersion A. Filter the nickel oxide nanoparticle dispersion after ultrasonic treatment with a water-based filter. Spin-coat the filtered dispersion A on FTO at 2000 r / s and anneal it at 150 °C for 10 minutes to obtain thin film A.
[0048] (2) Disperse 1 mg of Me-4PACz in 2 ml of absolute ethanol, and stir for 3 h to obtain solution B. Spin-coat it on thin film A at 4000 r / s in a nitrogen glove box and anneal it at 100 °C for 10 minutes to obtain thin film B.
[0049] (3) Disperse 2 mg of fluoronaphthalene in 1 ml of isopropanol, and stir for 3 h to obtain solution C. Spin-coat it on thin film B at 5000 r / s in a nitrogen glove box and anneal it at 100 °C for 10 minutes to obtain thin film C.
[0050] (4) Dissolve 13.5 mg of MACl, 20.78 mg of CsI, 22.25 mg of PbCl2, 261.39 mg of FAI, and 737.62 mg of PbI2 in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide (DMF:DMSO = 4:1 v%), and stir for 6 h to obtain solution D. Before use, filter the perovskite precursor solution with a polytetrafluoroethylene filter membrane, and spin-coat solution D on film C by a two-step method. First, spin-coat at 1000 r / s for 10 s, then spin-coat at 5000 r / s for 30 s, and add 150 μL of anisole when the countdown reaches 6 s, and anneal at 120 °C for 20 minutes to obtain film D.
[0051] (5) Dissolve 1 mg of PDAI2 in 1 ml of isopropanol, stir for 3 h to obtain solution E, spin-coat it on film D at 5000 r / s in a nitrogen-filled glove box, and anneal at 100 °C for 10 minutes to obtain film E.
[0052] (6) Evaporate C60, bathocuproine (BCP), and silver (Ag) on film E in a vacuum coating machine, with thicknesses of 250 nm, 60 nm, and 1100 nm respectively, to complete the preparation of the perovskite solar cell device.
[0053] As Figure 3 shown, for the device passivated with fluoronaphthalene, the breakdown voltage is increased from -0.91 V of the control sample to -1.55 V. And the efficiency of the related device ( Figure 4 shown) is also increased from 24.38% of the control sample ( J SC = 25.85 mA cm -2 ; V OC = 1.157 V; FF = 81.51%) to 25.01% ( J SC = 25.53 mA cm -2 ; V OC = 1.178 V; FF = 83.09%). Thus, it can be seen that fluoronaphthalene is very beneficial to improving the efficiency and reverse breakdown voltage of perovskite solar cells.
[0054] Example 3: The method for improving the reverse breakdown voltage of the perovskite solar cell in this example includes the following steps: (1) Disperse 10 mg of nickel oxide nanoparticles in 1 ml of deionized water, and ultrasonically disperse it at low temperature (0 °C) for 40 min to obtain dispersion A. Filter the nickel oxide nanoparticle dispersion after ultrasonic treatment with a water-based filter. Spin-coat the filtered dispersion A on FTO at 2000 r / s and anneal it at 150 °C for 10 minutes to obtain film A.
[0055] (2) Disperse 1 mg of Me-4PACz in 2 ml of absolute ethanol, and stir for 3 h to obtain solution B. Spin-coat it on film A at 4000 r / s in a nitrogen-filled glove box and anneal it at 100 °C for 10 minutes to obtain film B.
[0056] (3) Disperse 2 mg of 2,3-dicyanonaphthalene in 1 ml of isopropanol, and stir for 3 h to obtain solution C. Spin-coat it on film B at 5000 r / s in a nitrogen-filled glove box and anneal it at 100 °C for 10 minutes to obtain film C.
[0057] (4) Dissolve 13.5 mg of MACl, 20.78 mg of CsI, 22.25 mg of PbCl2, 261.39 mg of FAI, and 737.62 mg of PbI2 in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide (DMF:DMSO = 4:1 v%), and stir for 6 h to obtain solution D. Filter the perovskite precursor solution with a polytetrafluoroethylene filter membrane before use. Spin-coat solution D on film C by a two-step method. First, spin-coat it at 1000 r / s for 10 s, then spin-coat it at 5000 r / s for 30 s, and add 150 μL of anisole when the countdown reaches 6 s. Anneal it at 120 °C for 20 minutes to obtain film D.
[0058] (5) Dissolve 1 mg of PDAI2 in 1 ml of isopropanol, and stir for 3 h to obtain solution E. Spin-coat it on film D at 5000 r / s in a nitrogen-filled glove box and anneal it at 100 °C for 10 minutes to obtain film E.
[0059] (6) Evaporate C60, bathocuproine (BCP), and silver (Ag) on film E in a vacuum coating machine, with thicknesses of 250 nm, 60 nm, and 1100 nm respectively, to complete the preparation of the perovskite solar cell device.
[0060] As shown by Figure 5 For the device passivated with 2,3-dicyanonaphthalene, the breakdown voltage is increased from -0.91 V of the control sample to -3.56 V. And the efficiency of the related device ( Figure 6 as shown) is also increased from 24.38% of the control sample ( J SC = 25.85 mA cm -2; V OC = 1.157 V; FF = 81.51%) to 25.35% ( J SC = 26.00 mA cm -2 ; V OC = 1.166 V; FF = 83.60%). It can be seen that 2,3-dicyanonaphthalene is very beneficial to improving the efficiency and reverse breakdown voltage of perovskite solar cells.
[0061] Example 4: The method for improving the reverse breakdown voltage of the perovskite solar cell in this example includes the following steps: (1) Disperse 10 mg of nickel oxide nanoparticles in 1 ml of deionized water, and ultrasonically disperse at low temperature (0 °C) for 40 min to obtain dispersion liquid A. Filter the nickel oxide nanoparticle dispersion after ultrasonic treatment with a water-based filter. Spin-coat the filtered dispersion liquid A on FTO at 2000 r / s and anneal at 150 °C for 10 minutes to obtain film A.
[0062] (2) Disperse 1 mg of Me-4PACz in 2 ml of absolute ethanol, and stir for 3 h to obtain solution B. Spin-coat it on film A at 4000 r / s in a nitrogen glove box and anneal at 100 °C for 10 minutes to obtain film B.
[0063] (3) Disperse 2 mg of 2,3-dicyanothiophene in 1 ml of isopropanol, and stir for 3 h to obtain solution C. Spin-coat it on film B at 5000 r / s in a nitrogen glove box and anneal at 100 °C for 10 minutes to obtain film C.
[0064] (4) Dissolve 13.5 mg of MACl, 20.78 mg of CsI, 22.25 mg of PbCl2, 261.39 mg of FAI, and 737.62 mg of PbI2 in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide (DMF:DMSO = 4:1 v%), stir for 6 h to obtain solution D. Filter the perovskite precursor solution with a polytetrafluoroethylene filter membrane before use. Spin-coat solution D on film C by a two-step method, first spin-coat at 1000 r / s for 10 s, then spin-coat at 5000 r / s for 30 s, and add 150 μL of anisole at the 6th second of the countdown, and anneal at 120 °C for 20 minutes to obtain film D.
[0065] (5) Dissolve 1 mg of PDAI2 in 1 ml of isopropanol, stir for 3 h to obtain solution E, spin-coat it on film D at 5000 r / s in a nitrogen-filled glove box, and anneal at 100 °C for 10 minutes to obtain film E.
[0066] (6) Evaporate C60, bathocuproine (BCP) and silver (Ag) on film E in a vacuum coater, with thicknesses of 250 nm, 60 nm and 1100 nm respectively, to complete the preparation of the perovskite solar cell device.
[0067] As Figure 7 shown, for the device passivated with 2,3-dicyanothiophene, the breakdown voltage is increased from -0.91 V of the control sample to -4.24 V. And the efficiency of the related device ( Figure 8 shown) is also increased from 24.38% of the control sample ( J SC Jsc = 25.85 mA cm -2 ; V OC Voc = 1.157 V; FF = 81.51%) to 25.42% ( J SC Jsc = 25.53 mA cm -2 ; V OC Voc = 1.172 V; FF = 84.97%). Thus, it can be seen that 2,3-dicyanothiophene is very beneficial to improving the efficiency and reverse breakdown voltage of perovskite solar cells.
[0068] Example 5: The method for improving the reverse breakdown voltage of the perovskite solar cell in this example includes the following steps: (1) Disperse 10 mg of nickel oxide nanoparticles in 1 ml of deionized water, and ultrasonically disperse them at low temperature (0 °C) for 40 min to obtain dispersion A. Filter the nickel oxide nanoparticle dispersion after ultrasonic treatment with a water-based filter. Spin-coat the filtered dispersion A on FTO at 2000 r / s and anneal at 150 °C for 10 minutes to obtain film A.
[0069] (2) Disperse 1 mg of Me-4PACz in 2 ml of absolute ethanol, stir for 3 h to obtain solution B. Spin-coat it on film A at 4000 r / s in a nitrogen-filled glove box and anneal at 100 °C for 10 minutes to obtain film B.
[0070] (3) Disperse 2 mg of pyridinium p-toluenesulfonate in 1 ml of isopropanol and stir for 3 h to obtain solution C. Spin-coat it on film B at 5000 r / s in a nitrogen-filled glove box and anneal at 100 °C for 10 minutes to obtain film C.
[0071] (4) Dissolve 13.5 mg of MACl, 20.78 mg of CsI, 22.25 mg of PbCl2, 261.39 mg of FAI, and 737.62 mg of PbI2 in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide (DMF:DMSO = 4:1 v%). Stir for 6 h to obtain solution D. Before use, filter the perovskite precursor solution with a polytetrafluoroethylene filter membrane. Spin-coat solution D on film C by a two-step method. First, spin-coat at 1000 r / s for 10 s, then spin-coat at 5000 r / s for 30 s. Drop 150 μL of anisole at the 6 s countdown and anneal at 120 °C for 20 minutes to obtain film D.
[0072] (5) Dissolve 1 mg of PDAI2 in 1 ml of isopropanol and stir for 3 h to obtain solution E. Spin-coat it on film D at 5000 r / s in a nitrogen-filled glove box and anneal at 100 °C for 10 minutes to obtain film E.
[0073] (6) Evaporate C60, bathocuproine (BCP), and silver (Ag) on film E in a vacuum coater with thicknesses of 250 nm, 60 nm, and 1100 nm respectively to complete the preparation of the perovskite solar cell device.
[0074] As Figure 9 shown, for the device passivated with pyridinium p-toluenesulfonate, the breakdown voltage is increased from -0.91 V of the control sample to -3.72 V. And the efficiency of the related device ( Figure 10 shown) is also increased from 24.38% of the control sample ( J SC = 25.85 mA cm -2 ; V OC =1.157 V; FF = 81.51%) to 25.85% ( J SC = 25.88 mA cm -2 ; V OC = 1.171 V; FF =85.28%). Thus, it can be seen that pyridinium p-toluenesulfonate is very beneficial to improving the efficiency and reverse breakdown voltage of perovskite solar cells.
[0075] Example 6: The method for improving the reverse breakdown voltage of a perovskite solar cell in this embodiment includes the following steps: (1) Disperse 10 mg of nickel oxide nanoparticles in 1 ml of deionized water, and ultrasonically disperse them at low temperature (0 °C) for 40 min to obtain dispersion A. Filter the nickel oxide nanoparticle dispersion after ultrasonic treatment with a water-based filter. Spin-coat the filtered dispersion A on FTO at 2000 r / s and anneal it at 150 °C for 10 minutes to obtain film A.
[0076] (2) Disperse 1 mg of Me-4PACz in 2 ml of absolute ethanol, and stir for 3 h to obtain solution B. Spin-coat it on film A at 4000 r / s in a nitrogen glove box and anneal it at 100 °C for 10 minutes to obtain film B.
[0077] (3) Disperse 2 mg of 5-fluorouracil in 1 ml of isopropanol, and stir for 3 h to obtain solution C. Spin-coat it on film B at 5000 r / s in a nitrogen glove box and anneal it at 100 °C for 10 minutes to obtain film C.
[0078] (4) Dissolve 72.7 mg of CsI, 19.5 mg of PbCl2, 35 mg of FABr, 144.5 mg of FAI, 154.2 mg of PbBr2, and 440.5 mg of PbI2 in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide (DMF:DMSO = 4:1 v%), stir for 6 h to obtain solution D. Filter the perovskite precursor solution with a polytetrafluoroethylene filter before use, and spin-coat solution D on film C by a two-step method. First, spin-coat at 1000 r / s for 10 s, then spin-coat at 5000 r / s for 30 s, and add 150 μL of anisole when the countdown reaches 6 s, and anneal at 120 °C for 20 minutes to obtain film D.
[0079] (5) Dissolve 1 mg of PDAI2 in 1 ml of isopropanol, and stir for 3 h to obtain solution E. Spin-coat it on film D at 5000 r / s in a nitrogen glove box and anneal it at 100 °C for 10 minutes to obtain film E.
[0080] (6) Evaporate C60, bathocuproine (BCP), and silver (Ag) on film E in a vacuum coater, with thicknesses of 250 nm, 60 nm, and 1100 nm respectively, to complete the preparation of the perovskite solar cell device.
[0081] As Figure 11 shown, for the device passivated with 5-fluorouracil, the breakdown voltage is increased from -0.1 V of the control sample to -5.43 V. And the efficiency of the related device ( Figure 12 shown) also increases from 20.64% of the control sample (J SC = 21.48 mA cm -2 ; V OC = 1.214 V; FF = 79.10%) to 21.86% ( J SC = 21.97 mA cm -2 ; V OC = 1.221 V; FF = 82.06%). It can be seen that 5-fluorouracil is very beneficial to improving the efficiency and reverse breakdown voltage of perovskite solar cells.
[0082] As can be seen from the above solutions of the present invention, the present invention uses strongly polar organic small molecules with high electronegativity to modify the buried interface, thereby improving the hydrophilicity of the bottom, passivating the exposed lead atoms of perovskite and filling the halogen vacancies, and improving the quality of the perovskite buried bottom film. In addition, the introduction of strongly polar organic small molecules with high electronegativity in the present invention can also increase the dielectric constant of perovskite, thereby significantly increasing the reverse breakdown voltage of perovskite solar cells. Therefore, the perovskite solar cells prepared by this patent have higher stability under reverse bias voltage, which is more conducive to the commercialization of perovskite solar cells.
[0083] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.
[0084] It should also be noted that the above are only the preferred embodiments of the present application, and do not limit the patent protection scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.
Claims
1. A method for increasing the reverse breakdown voltage of a perovskite solar cell, characterized in that: The process includes the following: A dielectric protective layer is arranged between the hole transport layer and the perovskite light absorbing layer of the perovskite solar cell. The dielectric protective layer is prepared on the surface of the hole transport layer by a spin coating process. The solution used to prepare the dielectric protective layer is a solution made of a polar solvent and organic small molecules with strong polar groups. The strong polar groups include at least one of a nitro group, a sulfonic acid group, a cyano group and a fluorine group.
2. A method for improving the reverse breakdown voltage of a perovskite solar cell according to claim 1, characterized in that: In the solution used to prepare the dielectric protection layer, the concentration of the organic small molecules is 1.9-2.1 mg / ml.
3. The method for improving the reverse breakdown voltage of a perovskite solar cell according to claim 1, characterized in that: The organic small molecule is at least one of chlorobis(4-fluorophenyl)phosphine, fluoronaphthalene, 2,3-dicyanonaphthalene, 2,3-dicyanothiophene, pyridine p-toluenesulfonate and 5-fluorouracil.
4. The method for improving the reverse breakdown voltage of a perovskite solar cell according to claim 1, characterized in that: The polar solvent is isopropanol.
5. The method for improving the reverse breakdown voltage of a perovskite solar cell according to claim 1, characterized in that: The process of preparing a dielectric protection layer on the surface of the hole transport layer by spin coating includes: The solution for preparing the dielectric protection layer is spin-coated on the hole transport layer at 4950-5050 r / s in a protective atmosphere. After the spin coating is completed, annealing is performed at 95-105° C. for 9-11 minutes to form the dielectric protection layer.
6. A method for improving the reverse breakdown voltage of a perovskite solar cell according to any one of claims 1 to 5, characterized in that: It also includes the following processes: A hole transport layer is prepared on the surface of the transparent electrode layer, a dielectric protective layer is prepared on the surface of the hole transport layer, a perovskite light absorption layer is prepared on the surface of the dielectric protective layer, and then an interface passivation layer, an electron transport layer, a hole blocking layer and an electrode are sequentially prepared on the surface of the perovskite light absorption layer.
7. A method for improving the reverse breakdown voltage of a perovskite solar cell according to claim 6, characterized in that: The transparent electrode layer is made of fluorine-doped indium tin oxide conductive glass or indium tin oxide conductive glass.
8. The method for improving the reverse breakdown voltage of a perovskite solar cell according to claim 6, characterized in that: The process of preparing a hole transport layer on the surface of a transparent electrode layer includes: A deionized water dispersion of nano nickel oxide with a concentration of 9-11 mg / ml was spin-coated on the surface of the transparent electrode layer at 1950-2050 r / s, and then annealed at 145-155 °C for 9-11 minutes to obtain a film A; A 0.4-0.6 mg / ml dispersion of [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid in anhydrous ethanol was spin-coated on the surface of film A at 3950-4050 r / s, and then annealed at 95-105 °C for 9-11 minutes to obtain film B; The film A and the film B constitute a hole transport layer.
9. The method for improving the reverse breakdown voltage of a perovskite solar cell according to claim 6, characterized in that: The process of preparing an interface passivation layer on the surface of the perovskite light absorbing layer includes: spin coating an isopropanol solution of 1,3-diaminopropane dihydroiodide with a concentration of 0.9-1.1 mg / ml on the surface of the perovskite light absorbing layer at 4950-5050 r / s in a protective atmosphere, and then annealing at 95-105° C. for 9-11 minutes to obtain the interface passivation layer; Carbon 60, copper and silver are sequentially evaporated on the surface of the interface passivation layer to sequentially form an electron transport layer, a hole blocking layer and an electrode; wherein the thicknesses of the electron transport layer, the hole blocking layer and the electrode are 245-255 nm, 55-65 nm and 1095-1105 nm, respectively.
10. A perovskite solar cell obtained by the method for improving the reverse breakdown voltage of a perovskite solar cell according to any one of claims 1 to 9.