Perovskite solar cell and preparation method thereof

Abstract

The invention provides a perovskite solar cell and a preparation method thereof. The perovskite solar cell comprises a substrate, a modified nickel oxide hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode which are stacked in sequence, wherein the modified nickel oxide hole transport layer is a nickel oxide hole transport layer modified by aminoethyl substituted maleimide salt. By introducing the modified nickel oxide hole transport layer into the perovskite solar cell, the photoelectric conversion efficiency and stability of the cell can be significantly improved, and the problem of structural damage caused by direct contact of nickel oxide and perovskite is avoided. Specifically, amino in aminoethyl substituted maleimide salt acts with perovskite, and oxygen in the aminoethyl substituted maleimide salt is connected with a nickel oxide layer, so that direct contact between nickel oxide and the perovskite layer can be isolated, damage of nickel oxide to the perovskite is avoided, a bridging effect between the perovskite and nickel oxide is achieved, and the performance of the perovskite solar cell is improved. Therefore, the photoelectric conversion efficiency of the cell is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a perovskite solar cell and a preparation method thereof. Background Art

[0002] Nickel oxide is a commonly used hole transport layer material in inverse perovskite solar cells. It has the advantages of being stable, cheap, and easy to prepare. However, the highly active oxidation states on the surface of nickel oxide, such as Ni 3+ It will react with the A-site cations in the perovskite, causing the collapse of the perovskite structure and affecting the photoelectric conversion efficiency and stability of the device. Therefore, it is of great significance to modify nickel oxide and reduce the damage of the surface highly active oxidation state to the perovskite film. Summary of the invention

[0003] The main purpose of the present invention is to provide a perovskite solar cell and a preparation method thereof, so as to solve the problem in the prior art that the highly active oxidation state of nickel oxide surface destroys the perovskite film.

[0004] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a perovskite solar cell is provided, which comprises a substrate, a modified nickel oxide hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode stacked in sequence; wherein the modified nickel oxide hole transport layer is a nickel oxide hole transport layer modified by aminoethyl substituted maleimide salt.

[0005] Furthermore, the above-mentioned aminoethyl substituted maleimide salt is N-(2-aminoethyl)maleimide trifluoroacetate and / or N-(2-aminoethyl)maleimide hydrochloride.

[0006] Furthermore, the substrate is FTO and / or ITO.

[0007] Furthermore, the perovskite absorption layer is a halide perovskite, and the chemical formula of the crystal structure of the halide perovskite is ABX3, wherein A is an organic cation and / or an inorganic cation, B is a divalent metal ion, and X is a halogen ion; and / or the divalent metal ion is Pb 2+ or Sn 2+ , the halogen ion is selected from I - Br - and Cl - Any one or more of .

[0008] Furthermore, the electrode is selected from any one or more of a metal electrode, a conductive oxide transparent electrode, a carbon electrode and a graphite electrode.

[0009] Furthermore, the material of the electron transport layer is selected from any one or more of C60, (6,6)-phenyl-C61-butyric acid methyl ester and tin dioxide.

[0010] According to another aspect of the present invention, a method for preparing the above-mentioned perovskite solar cell is provided, and the preparation method comprises: step S1, preparing a nickel oxide hole transport layer on a substrate; step S2, modifying the nickel oxide hole transport layer by using aminoethyl to replace maleimide salt to obtain a modified nickel oxide hole transport layer; step S3, sequentially preparing a perovskite absorption layer, an electron transport layer and an electrode on the modified nickel oxide hole transport layer to obtain a perovskite solar cell.

[0011] Furthermore, the above-mentioned aminoethyl substituted maleimide salt is N-(2-aminoethyl) maleimide trifluoroacetate and / or N-(2-aminoethyl) maleimide hydrochloride, and the preparation method of the modified nickel oxide hole transport layer includes: dissolving N-(2-aminoethyl) maleimide trifluoroacetate and / or N-(2-aminoethyl) maleimide hydrochloride in isopropanol to obtain a solution, coating the solution on the surface of the nickel oxide hole transport layer, and then annealing to obtain the modified nickel oxide hole transport layer.

[0012] Furthermore, the mass concentration of the aminoethyl substituted maleimide salt in the above solution is 0.1-10 mg / mL, preferably 1-10 mg / mL, and / or the annealing temperature is 60-150° C., and the annealing time is 5-20 min.

[0013] Furthermore, in the above step S3, the preparation method of the perovskite absorption layer is selected from any one or more of spin coating, blade coating and slit coating.

[0014] By applying the technical solution of the present invention, the present application can significantly improve the photoelectric conversion efficiency and stability of the battery by introducing a modified nickel oxide hole transport layer into the perovskite solar cell, and avoid the problem of structural damage caused by direct contact between nickel oxide and perovskite. Specifically, by using aminoethyl to replace the amino group in the maleimide salt to react with the perovskite, the oxygen in the aminoethyl to replace the maleimide salt is connected to the nickel oxide layer, which can isolate the nickel oxide from the direct contact with the perovskite layer on the one hand, avoiding the damage of nickel oxide to the perovskite, and on the other hand, it plays a bridging role between the perovskite and the nickel oxide, thereby enhancing the interface bonding between the two, and thus improving the photoelectric conversion efficiency of the battery. DETAILED DESCRIPTION

[0015] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0016] As analyzed in the background technology of this application, there is a problem in the prior art that the high active oxidation state of the nickel oxide surface destroys the perovskite film. In order to solve the above problem, this application provides a perovskite solar cell and a preparation method thereof.

[0017] In a typical embodiment of the present application, a perovskite solar cell is provided, which comprises a substrate, a modified nickel oxide hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode stacked in sequence; wherein the modified nickel oxide hole transport layer is a nickel oxide hole transport layer modified by aminoethyl substituted maleimide salt.

[0018] The present application can significantly improve the photoelectric conversion efficiency and stability of the cell by introducing a modified nickel oxide hole transport layer into the perovskite solar cell, and avoid the problem of structural damage caused by direct contact between nickel oxide and perovskite. Specifically, by using aminoethyl to replace the amino group in the maleimide salt to react with the perovskite, the oxygen in the aminoethyl to replace the maleimide salt is connected to the nickel oxide layer, which can isolate the nickel oxide from the direct contact with the perovskite layer on the one hand, avoiding the damage of the nickel oxide to the perovskite, and on the other hand, it plays a bridging role between the perovskite and the nickel oxide, thereby enhancing the interface bonding between the two, and thus improving the photoelectric conversion efficiency of the cell.

[0019] In one embodiment of the present application, the aminoethyl-substituted maleimide salt is N-(2-aminoethyl)maleimide trifluoroacetate and / or N-(2-aminoethyl)maleimide hydrochloride.

[0020] On the one hand, the preferred aminoethyl substituted maleimide salts of the above type help to maximize the inhibition of Ni 3+ The high-activity oxidation states such as iodine and iodine can damage the perovskite, while enhancing the charge transfer between interfaces, further improving the performance of the modified layer, achieving the best isolation and bridging effect, and thus improving the overall performance of the battery. On the other hand, the anions trifluoroacetic acid ions and chloride ions have a strong effect on lead, which helps to passivate the low-coordinated lead defects in the perovskite and enhance the crystallization quality of the perovskite film.

[0021] In one embodiment of the present application, the substrate is FTO and / or ITO.

[0022] The substrate material is preferably controlled within the above range, which helps to provide good conductivity and transparency, thereby effectively transporting holes, while helping sunlight to penetrate through the perovskite absorption layer, thereby facilitating efficient photoelectric conversion of the battery.

[0023] In one embodiment of the present application, the perovskite absorption layer is a halide perovskite, and the chemical formula of the crystal structure of the halide perovskite is ABX3, wherein A is an organic cation and / or an inorganic cation, B is a divalent metal ion, and X is a halogen ion; and / or the divalent metal ion is Pb 2+ or Sn 2+ , the halogen ion is selected from I - Br - and Cl - Any one or more of .

[0024] The use of halide perovskite absorption layer is conducive to significantly improving the photoelectric conversion efficiency of the battery. Since halide perovskite has a high absorption coefficient, a long carrier diffusion length and a high carrier mobility, it is an ideal light absorption material. The adjustability of its crystal structure allows the band gap and stability of the perovskite to be adjusted by changing A, B, and X to different types of ions, thereby optimizing the battery performance. Therefore, it is preferred to control A to be a cation, B to be a metal ion, and X to be a halide ion within the above range, which is conducive to adjusting the optical and electrical properties of the perovskite to meet different application requirements.

[0025] In one embodiment of the present application, the electrode is selected from any one or more of a metal electrode, a conductive oxide transparent electrode, a carbon electrode and a graphite electrode.

[0026] Different types of electrode materials have different conductivity and stability. It is preferred to control the electrode material within the above range, which helps to provide stable electrical contact and good conductivity, while reducing the preparation cost of the battery or improving its transparency, making it more suitable for the needs of different application scenarios.

[0027] In one embodiment of the present application, the material of the electron transport layer is selected from any one or more of C60, (6,6)-phenyl-C61-butyric acid methyl ester (PCBM for short) and tin dioxide.

[0028] Materials such as C60, (6,6)-phenyl-C61-butyric acid methyl ester and tin dioxide have good electron transport performance and stable chemical properties. Therefore, by controlling the material of the electron transport layer within the above range, it is beneficial to effectively collect electrons from the perovskite layer and transmit them to the electrode, thereby reducing energy loss inside the battery and improving the overall efficiency of the battery.

[0029] In another typical embodiment of the present application, a method for preparing the above-mentioned perovskite solar cell is provided, and the preparation method comprises: step S1, preparing a nickel oxide hole transport layer on a substrate; step S2, modifying the nickel oxide hole transport layer with an aminoethyl-substituted maleimide salt to obtain a modified nickel oxide hole transport layer; step S3, sequentially preparing a perovskite absorption layer, an electron transport layer and an electrode on the modified nickel oxide hole transport layer to obtain a perovskite solar cell.

[0030] The present application discloses a method for preparing the above-mentioned perovskite solar cell, which is prepared in steps, each step is targeted at a specific functional layer, and the composition and structure of the material are precisely regulated, thereby reducing the incompatibility between different materials during the preparation process, thereby improving the photoelectric conversion efficiency and stability of the battery. The key is to use aminoethyl to replace maleimide salt to modify the nickel oxide hole transport layer, which can isolate the direct contact between nickel oxide and the perovskite layer on the one hand, avoiding the damage of nickel oxide to perovskite, and on the other hand, it plays a bridging role between perovskite and nickel oxide, thereby enhancing the interface bonding between the two, thereby improving the photoelectric conversion efficiency of the battery. The preparation method is simple in process, low in cost of each raw material, and has good application prospects for high-performance optoelectronic devices.

[0031] In one embodiment of the present application, the above-mentioned aminoethyl substituted maleimide salt is N-(2-aminoethyl) maleimide trifluoroacetate and / or N-(2-aminoethyl) maleimide hydrochloride, and the method for preparing the modified nickel oxide hole transport layer includes: dissolving N-(2-aminoethyl) maleimide trifluoroacetate and / or N-(2-aminoethyl) maleimide hydrochloride in isopropanol to obtain a solution, coating the solution on the surface of the nickel oxide hole transport layer, and then annealing to obtain the modified nickel oxide hole transport layer.

[0032] The present application provides a method for modifying a nickel oxide hole transport layer, wherein N-(2-aminoethyl)maleimide trifluoroacetate and / or N-(2-aminoethyl)maleimide hydrochloride are dissolved in isopropanol to prepare a solution, and the solution is then coated on the surface of the nickel oxide hole transport layer, wherein a modified nickel oxide hole transport layer with optimal thickness and properties can be formed by adjusting the solution concentration and annealing conditions, thereby effectively isolating the nickel oxide from direct contact with the perovskite, reducing the risk of nickel oxide damaging the perovskite, and also facilitating interface bridging and improving battery performance.

[0033] In one embodiment of the present application, the mass concentration of the aminoethyl substituted maleimide salt in the above solution is 0.1-10 mg / mL, preferably 1-10 mg / mL, and / or the annealing temperature is 60-150° C., and the annealing time is 5-20 min.

[0034] The selection of solution concentration, annealing temperature and time is crucial to the formation of the modified layer. If the concentration of the solution is too low, there may be no obvious effect. If the concentration of the solution is too high, the filling of the battery may be reduced, resulting in an increase in series resistance. Therefore, it is preferred to control the mass concentration of the solution, the temperature and time of the annealing treatment within the above range, which is conducive to the uniform distribution and full reaction of the modifier on the surface of nickel oxide, forming a modified layer with optimal thickness and properties. This modified layer can effectively isolate the direct contact between nickel oxide and perovskite, while promoting interface bridging and enhancing battery performance.

[0035] In one embodiment of the present application, in the above step S3, the preparation method of the perovskite absorption layer is selected from any one or more of spin coating, blade coating and slit coating.

[0036] Different preparation methods will affect the uniformity, density and crystallinity of the perovskite film. It is preferred to control the preparation method of the perovskite absorption layer within the above range, which can provide better perovskite film quality for different battery designs and application scenarios, and further improve the photoelectric conversion efficiency of the battery.

[0037] The beneficial effects of the present application will be further illustrated below in conjunction with embodiments.

[0038] Example 1

[0039] The FTO glass was cleaned with acetone, isopropanol, deionized water, and ethanol in an alternating ultrasonic manner for 10 minutes, dried with nitrogen, and then treated with UV-ozone for 20 minutes. A nickel oxide hole transport layer was deposited on the substrate by magnetron sputtering, with a vacuum pressure of 0.37 Pa, a power of 90 W, a deposition time of 10 minutes, and annealed at 300°C for 30 minutes;

[0040] 1 mg of N-(2-aminoethyl)maleimide trifluoroacetate was dissolved in 1 mL of isopropanol to obtain a solution, the solution was coated on the surface of the nickel oxide hole transport layer, and the temperature was raised to 100° C. and annealed for 10 min to obtain a modified nickel oxide hole transport layer;

[0041] The perovskite precursor solution was prepared in a nitrogen glove box: 232.8 mg FAI (iodine formamide), 7.98 mg MABr (methylammonium bromide), 19.49 mg CsI (cesium iodide), 27.53 mg PbBr2 (lead bromide), 676.6 mg PbI2 (lead iodide), 30.38 mg MACl (methylammonium chloride) were weighed and mixed with 0.8 mL N,N-dimethylformamide and 0.2 mL dimethyl sulfoxide, and stirred at 25 ° C and 800 rpm for 2 h to obtain a perovskite precursor solution; wherein, the perovskite precursor (FAI) 0.95 MA 0.05 ) 0.95 Cs0.05 Pb(I 0.95 Br 0.05 )3 has a molar concentration of 1.5 mol / L, 100 μL of the perovskite precursor solution is dropped on the modified nickel oxide hole transport layer, first spin-coated at 2000 rpm for 10 s, then spin-coated at 5000 rpm for 40 s, 200 μL of chlorobenzene is quickly added 15 s before the end of spin coating for anti-solvent treatment, and then placed on a 100 ° C hot stage for annealing for 30 min to obtain a perovskite absorption layer with a thickness of 400 nm;

[0042] By vacuum evaporation, a 20nm thick C60 electron transport layer, a 5nm thick 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP) buffer layer and a 150nm thick copper electrode were prepared in sequence on the perovskite absorption layer, and finally a perovskite solar cell was obtained.

[0043] Example 2

[0044] The difference from Example 1 is that the concentration of N-(2-aminoethyl)maleimide trifluoroacetate is 2 mg / mL, and a perovskite solar cell is finally prepared.

[0045] Example 3

[0046] The difference from Example 1 is that the concentration of N-(2-aminoethyl)maleimide trifluoroacetate is 5 mg / mL, and a perovskite solar cell is finally prepared.

[0047] Example 4

[0048] The difference from Example 1 is that the concentration of N-(2-aminoethyl)maleimide trifluoroacetate is 0.1 mg / mL, and a perovskite solar cell is finally prepared.

[0049] Example 5

[0050] The difference from Example 1 is that N-(2-aminoethyl)maleimide trifluoroacetate is replaced by N-(2-aminoethyl)maleimide hydrochloride, and finally a perovskite solar cell is prepared.

[0051] Example 6

[0052] The difference from Example 5 is that the mass concentration of N-(2-aminoethyl)maleimide hydrochloride is 2 mg / mL, and the perovskite solar cell is finally prepared.

[0053] Example 7

[0054] The difference from Example 5 is that the mass concentration of N-(2-aminoethyl)maleimide hydrochloride is 5 mg / mL, and the perovskite solar cell is finally prepared.

[0055] Example 8

[0056] The difference from Example 5 is that the mass concentration of N-(2-aminoethyl)maleimide hydrochloride is 0.1 mg / mL, and the perovskite solar cell is finally prepared.

[0057] Comparative Example 1

[0058] The difference from Example 1 is that the nickel oxide hole transport layer is not modified, and the perovskite solar cell is finally prepared.

[0059] Performance Test:

[0060] At room temperature, using a 3A solar simulator, at 100mW / cm 2 Under the light intensity, the IV curves of the batteries prepared in the embodiment and the comparative example were tested to obtain the short-circuit current density, open-circuit voltage, fill factor and photoelectric conversion efficiency. The test results are shown in Table 1, where the effective area of ​​the battery is 0.09 cm 2 .

[0061] Table 1

[0062]

[0063] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0064] The present application can significantly improve the photoelectric conversion efficiency and stability of the cell by introducing a modified nickel oxide hole transport layer into the perovskite solar cell, and avoid the problem of structural damage caused by direct contact between nickel oxide and perovskite. Specifically, by using aminoethyl to replace the amino group in the maleimide salt to react with the perovskite, the oxygen in the aminoethyl to replace the maleimide salt is connected to the nickel oxide layer, which can isolate the nickel oxide from the direct contact with the perovskite layer on the one hand, avoiding the damage of the nickel oxide to the perovskite, and on the other hand, it plays a bridging role between the perovskite and the nickel oxide, thereby enhancing the interface bonding between the two, and thus improving the photoelectric conversion efficiency of the cell.

[0065] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A perovskite solar cell, characterized in that: The perovskite solar cell comprises a substrate, a modified nickel oxide hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode which are stacked in sequence; Wherein, the modified nickel oxide hole transport layer is a nickel oxide hole transport layer modified by aminoethyl substituted maleimide salt.

2. The perovskite solar cell according to claim 1, characterized in that The aminoethyl substituted maleimide salt is N-(2-aminoethyl)maleimide trifluoroacetate and / or the N-(2-aminoethyl)maleimide hydrochloride.

3. The perovskite solar cell according to claim 1 or 2, characterized in that: The substrate is FTO and / or ITO.

4. The perovskite solar cell according to any one of claims 1 to 3, characterized in that The perovskite absorption layer is a halide perovskite, and the chemical formula of the crystal structure of the halide perovskite is ABX3, wherein A is an organic cation and / or an inorganic cation, B is a divalent metal ion, and X is a halogen ion; And / or, the divalent metal ion is Pb 2+ or Sn 2+ , the halogen ion is selected from I - Br - and Cl - Any one or more of .

5. The perovskite solar cell according to any one of claims 1 to 4, characterized in that The electrode is selected from any one or more of a metal electrode, a conductive oxide transparent electrode, a carbon electrode and a graphite electrode.

6. The perovskite solar cell according to any one of claims 1 to 5, characterized in that The material of the electron transport layer is selected from any one or more of C60, (6,6)-phenyl-C61-butyric acid methyl ester and tin dioxide.

7. A method for preparing a perovskite solar cell according to any one of claims 1 to 6, characterized in that: The preparation method comprises: Step S1, preparing a nickel oxide hole transport layer on a substrate; Step S2, modifying the nickel oxide hole transport layer by using aminoethyl to replace maleimide salt to obtain a modified nickel oxide hole transport layer; Step S3, sequentially preparing a perovskite absorption layer, an electron transport layer and an electrode on the modified nickel oxide hole transport layer to obtain the perovskite solar cell.

8. The preparation method according to claim 7, characterized in that: The aminoethyl substituted maleimide salt is N-(2-aminoethyl) maleimide trifluoroacetate and / or N-(2-aminoethyl) maleimide hydrochloride. The preparation method of the modified nickel oxide hole transport layer comprises: The N-(2-aminoethyl)maleimide trifluoroacetate and / or the N-(2-aminoethyl)maleimide hydrochloride are dissolved in isopropanol to obtain a solution, and the solution is coated on the surface of the nickel oxide hole transport layer, followed by annealing to obtain the modified nickel oxide hole transport layer.

9. The preparation method according to claim 8, characterized in that: The mass concentration of the aminoethyl substituted maleimide salt in the solution is 0.1-10 mg / mL, preferably 1-10 mg / mL, and / or the temperature of the annealing treatment is 60-150° C., and the time of the annealing treatment is 5-20 min.

10. The preparation method according to any one of claims 7 to 9, characterized in that: In the step S3, the preparation method of the perovskite absorption layer is selected from any one or more of spin coating, blade coating and slit coating.

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