Method for preparing perovskite cell by modifying electron transport layer with organic phosphonic acid scale inhibitor

Abstract

The invention discloses a method for preparing a perovskite cell by modifying an electron transport layer with an organic phosphonic acid scale inhibitor, and the method comprises the steps: S1, preparing a SnO2 dispersion liquid, preparing a SnO2 colloidal dispersion liquid with the concentration of 10 wt%, adding PBTCA molecules, and carrying out the ultrasonic treatment until the mixture is uniform, thereby obtaining a stable mixed solution; s2, coating the mixed solution prepared in the step S1 on a clean ITO glass substrate by using a spin-coating method, and then performing annealing treatment to form a SnO2 electron transport layer; s3, preparing a perovskite precursor solution which comprises a PbI2 solution and an FAI: MACl solution, and performing continuous spin coating and annealing to form a perovskite thin film; s4, a hole transport layer material Spiro-OMeTAD is spin-coated on the perovskite thin film; s5, depositing a silver electrode on the hole transport layer by adopting a thermal evaporation technology; and S6, testing the photoelectric conversion efficiency and the long-term stability of the prepared perovskite solar cell. The method enhances the photoelectric conversion efficiency and long-term stability of the perovskite solar cell, can be compatible with the existing cell preparation process, and has high industrial application potential.

Description

Technical Field

[0001] The invention belongs to the technical field of perovskite solar cells, and specifically relates to a method for preparing a perovskite cell by modifying an electron transport layer with an organic phosphonic acid scale inhibitor. Background Art

[0002] Perovskite solar cells have become a research hotspot in the photovoltaic field in recent years due to their excellent photoelectric conversion efficiency (theoretical efficiency is close to the Shockley–Queisser limit) and low-cost manufacturing process. Although its laboratory efficiency has exceeded 25%, close to the level of traditional crystalline silicon solar cells, its commercial application still faces many challenges, the most important of which is the poor stability of long-term operation, especially under actual working conditions such as high temperature, high humidity and ultraviolet light, its performance is prone to significant attenuation. The chemical stability of perovskite materials and the optimization of various interfaces inside the cell are the key to improving device stability and performance.

[0003] In the structure of perovskite solar cells, the electron transport layer (ETL) plays a role in the efficient extraction and transmission of photogenerated electrons, and its performance has an important influence on the efficiency and stability of the device. Tin dioxide (SnO2) is a promising material due to its excellent light transmittance, wide bandgap (3.6–4.0 eV), high electron mobility (>100 cm 2 / V·s) and chemical stability, it has become a mainstream electron transport material.

[0004] However, SnO2 still has the following deficiencies in practical applications: (i) Surface defects: Since there are often a large number of oxygen vacancies and unpaired electrons on the surface of SnO2, these defects can easily lead to non-radiative recombination, thereby reducing the photoelectric conversion efficiency of the device; (ii) Poor dispersibility: During solution processing, the dispersibility of SnO2 particles is crucial to the quality of the film, but in conventional preparation processes, SnO2 particles are prone to agglomeration, resulting in increased film roughness, which in turn causes uneven deposition of the perovskite layer and forms interface defects; (iii) Poor interface contact: The interface contact between SnO2 and the perovskite layer is usually not ideal, and there are problems of energy level mismatch or insufficient passivation.

[0005] These problems will lead to increased interfacial resistance, thereby inhibiting the efficient transfer and separation of charges. In response to the above problems, the present invention proposes a strategy of modifying the SnO2 electron transport layer using 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA). PBTCA is a multifunctional organic molecule that contains phosphoric acid and carboxylic acid groups in its molecular structure, which can provide strong adsorption capacity and excellent passivation effect at the same time. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a method for preparing a perovskite cell by modifying an electron transport layer with an organic phosphonic acid scale inhibitor, which can effectively passivate the defects on the SnO2 surface, improve the electron transport efficiency, and enhance the photoelectric conversion efficiency and long-term stability of the perovskite solar cell.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for preparing a perovskite battery by modifying an electron transport layer with an organic phosphonic acid scale inhibitor comprises the following steps:

[0009] Step S1, preparing a SnO2 dispersion, preparing a SnO2 colloidal dispersion with a concentration of 10 wt%, adding PBTCA molecules, and ultrasonically treating until a uniform and stable mixed solution is obtained;

[0010] Step S2, coating the mixed solution prepared in step S1 on a clean ITO glass substrate by spin coating, followed by annealing to form a SnO2 electron transport layer;

[0011] Step S3, preparing a perovskite precursor solution, including a PbI2 solution and a FAI:MACl solution, and continuously spin coating and annealing to form a perovskite film;

[0012] Step S4, spin coating the hole transport layer material Spiro-OMeTAD on the perovskite film;

[0013] Step S5, using thermal evaporation technology to deposit a silver electrode on the hole transport layer;

[0014] Step S6: testing the photoelectric conversion efficiency and long-term stability of the prepared perovskite solar cell.

[0015] Furthermore, in step S1, the concentration of PBTC molecules is 3 mg / mL, and the ultrasonic treatment time is 30 minutes.

[0016] Furthermore, in step S2, the spin coating condition is 3000 rpm, the spin coating time is 30 seconds, the annealing temperature is 150° C., and the annealing time is 20 minutes.

[0017] Furthermore, in step S3, the PbI2 solution has a concentration of 1.5 M, and the solvent is a mixed solution of DMF and DMSO with a volume ratio of 19:1; the concentration of the FAI:MACl solution is 90 mg / mL:9 mg / mL.

[0018] Furthermore, in step S4, the spin coating condition of the hole transport layer is 3000 rpm and the duration is 30 seconds.

[0019] Furthermore, in step S5, the evaporation rate of the silver electrode is The thickness is 100nm.

[0020] The present invention can effectively passivate the defects on the SnO2 surface through the interaction between 2-phosphonobutane-1,2,4-tricarboxylic acid molecules and SnO2, significantly reduce the recombination of electrons and holes, improve the electron transmission efficiency, and enhance the photoelectric conversion efficiency and long-term stability of the perovskite solar cell, especially the stability under wet heat and ultraviolet light conditions. The method is simple and easy to implement, can be compatible with the existing battery preparation process, and has strong industrial application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0022] Figure 1 This is a comparison diagram of the gelation phenomenon of the solution after adding the PBTCA additive to the SnO2 solution and the SnO2 solution;

[0023] Figure 2 Table 2 shows the effects of different concentrations of PBTCA additives on the performance of perovskite solar cell devices. DETAILED DESCRIPTION

[0024] The technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the present invention. It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those generally understood by ordinary technicians in the technical field to which the present invention belongs.

[0025] Example 1

[0026] Preparation of high-performance perovskite solar cells using 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) doped SnO2 nanocrystals:

[0027] S1. Prepare SnO2 dispersion: weigh SnO2 nanocrystalline powder, evenly disperse it in deionized water to prepare a SnO2 colloidal dispersion with a concentration of 10 wt%, add 3 mg / mL PBTCA molecules, and perform ultrasonic treatment for 30 minutes until a uniform and stable mixed solution is obtained;

[0028] S2, coating the mixed solution prepared in step S1 on a clean ITO glass substrate by spin coating at a speed of 3000 rpm for 30 seconds, followed by annealing at 150° C. for 20 minutes to form a SnO2 electron transport layer;

[0029] S3, prepare perovskite precursor solution, dissolve PbI2 powder in a mixed solvent of DMF and DMSO, the volume ratio of DMF and DMSO is 19:1, obtain a PbI2 solution with a concentration of 1.5M, prepare FAI:MACl solution with a concentration of 90mg / mL:9mg / mL, and spin coat at a speed of 1500rpm and 2000rpm respectively, and anneal into a perovskite film;

[0030] S4, spin coating the hole transport layer material Spiro-OMeTAD on the perovskite film, the concentration of the Spiro-OMeTAD precursor solution is 70 mg / mL, the spin coating speed is 3000 rpm, and the duration is 30 seconds;

[0031] S5. Using thermal evaporation technology, a silver electrode is deposited on the hole transport layer. The electrode thickness is 100nm and the evaporation rate is

[0032] S6. Test the photoelectric conversion efficiency and long-term stability of the prepared perovskite solar cells: Use a solar simulator or actual sunlight as the light source to measure the open circuit voltage (Voc), short circuit current (Jsc), fill factor (FF) and photoelectric conversion efficiency (PCE) of the perovskite solar cells to evaluate their photoelectric performance. The test results are shown in Figure 2 ;Place the perovskite solar cell in an appropriate test environment (such as a constant temperature and humidity chamber) and regularly measure its performance parameters to evaluate its long-term stability. This process aims to understand the lifespan and performance changes of the cell in actual applications.

[0033] The above is a detailed introduction to the method for preparing perovskite batteries by modifying the electron transport layer with an organic phosphonic acid scale inhibitor provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only applicable to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a perovskite battery by modifying an electron transport layer with an organic phosphonic acid scale inhibitor, characterized in that: The following steps are involved: Step S1, preparing a SnO2 dispersion, preparing a SnO2 colloidal dispersion with a concentration of 10 wt%, adding PBTCA molecules, and ultrasonically treating until a uniform and stable mixed solution is obtained; Step S2, coating the mixed solution prepared in step S1 on a clean ITO glass substrate by spin coating, followed by annealing to form a SnO2 electron transport layer; Step S3, preparing a perovskite precursor solution, including a PbI2 solution and a FAI:MACl solution, and continuously spin coating and annealing to form a perovskite film; Step S4, spin coating the hole transport layer material Spiro-OMeTAD on the perovskite film; Step S5, using thermal evaporation technology to deposit a silver electrode on the hole transport layer; Step S6: testing the photoelectric conversion efficiency and long-term stability of the prepared perovskite solar cell.

2. The method for preparing a perovskite battery by modifying an electron transport layer with an organic phosphonic acid scale inhibitor according to claim 1, characterized in that: In step S1, the concentration of PBTC molecules is 3 mg / mL, and the ultrasonic treatment time is 30 minutes.

3. The method for preparing a perovskite battery by modifying an electron transport layer with an organic phosphonic acid scale inhibitor according to claim 1, characterized in that: In the step S2, the spin coating condition is 3000 rpm, the spin coating time is 30 seconds, the annealing temperature is 150° C., and the annealing time is 20 minutes.

4. The method for preparing a perovskite battery by modifying an electron transport layer with an organic phosphonic acid scale inhibitor according to claim 1, characterized in that: In step S3, the PbI2 solution has a concentration of 1.5 M, and the solvent is a mixed solution of DMF and DMSO with a volume ratio of 19:1; the concentration of the FAI:MACl solution is 90 mg / mL:9 mg / mL.

5. The method for preparing a perovskite battery by modifying an electron transport layer with an organic phosphonic acid scale inhibitor according to claim 1, characterized in that: In the step S4, the spin coating condition of the hole transport layer is 3000 rpm and the duration is 30 seconds.

6. The method for preparing a perovskite battery by modifying an electron transport layer with an organic phosphonic acid scale inhibitor according to claim 1, characterized in that: In step S5, the evaporation rate of the silver electrode is The thickness is 100nm.

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