Carbon electrode perovskite solar cell and preparation method thereof

Abstract

The invention belongs to the field of photovoltaic energy, and particularly relates to a carbon electrode perovskite solar cell and a preparation method thereof.The perovskite solar cell sequentially comprises FTO conductive glass, a SnO2 electron transport layer, a perovskite active layer and a carbon electrode layer from bottom to top, the heating temperature of each layer in the perovskite solar cell is 150 DEG C or below, and the heating temperature of each layer in the perovskite solar cell is 150 DEG C or below. Wherein the carbon electrode is doped with paulownia phthalocyanine; the preparation process is simple, and the obtained perovskite solar cell is stable in performance, small in hysteresis effect, low in cost and suitable for industrial production.

Description

Technical Field

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

[0002] Perovskite solar cells are a disruptive photovoltaic technology developed in recent years. So far, the highest certified efficiency has exceeded 26%, which is comparable to the efficiency of traditional single-cell crystalline silicon solar cells. In addition, due to the wide availability of raw materials, simple preparation process, low equipment requirements for device preparation process, and high-throughput preparation by solution method, this type of optoelectronic device has attracted widespread attention. The advantages of low cost and high performance give it a greater competitive advantage in many scenarios, and it is expected to replace or partially replace traditional crystalline silicon cells. However, for perovskite solar cells, the highest cost is mainly concentrated in precious metal electrodes and expensive hole transport materials. Therefore, in order to further reduce the cost of perovskite cells, seeking cheap electrode materials and designing simpler device structures have become research hotspots in this field. Carbon materials are cheap and easy to obtain, with good stability. At the same time, carbon has a close Fermi level to precious metals such as gold or silver, and is a potential substitute for precious metal electrodes. As early as ten years ago, scientists applied carbon electrodes to perovskite solar cells and obtained a photoelectric conversion efficiency of 12.8%, with good long-term stability. Carbon electrodes can not only be used as electrode materials but also have a hole transport function, so a separate hole transport layer is not required in the carbon electrode perovskite battery structure. The device structure of a perovskite battery without a hole transport layer is generally transparent conductive glass / electron transport layer / perovskite active layer / carbon electrode, in which the carbon electrode acts as both an electrode and a hole conductor. Therefore, a carbon electrode with excellent performance has an important influence on battery performance. Summary of the invention

[0003] The object of the present invention is to provide a carbon electrode perovskite solar cell and a preparation method thereof. The hole transport layer performance of the carbon electrode is enhanced by adding an additive having a hole transport function to a commercial carbon slurry, thereby improving the cell efficiency. This solves the problems of carrier accumulation and non-radiative recombination at the interface (perovskite active layer / carbon electrode) of the carbon-based hole-free perovskite cell, thereby obtaining a high-performance composite carbon electrode and an efficient and stable carbon-based perovskite solar cell.

[0004] Based on the above object, the present invention is achieved through the following technical solutions:

[0005] A carbon electrode perovskite solar cell and a preparation method thereof, the process is as follows:

[0006] 1) adding copper phthalocyanine into commercial low-temperature carbon slurry and mixing them thoroughly, with the doping ratio being 0.5-5wt% to obtain a composite carbon slurry;

[0007] The carbon-based perovskite solar cell is prepared by using the aforementioned composite carbon slurry, wherein the perovskite solar cell is composed of a transparent conductive substrate, an electron transport layer, a perovskite light absorbing layer and a carbon electrode in sequence.

[0008] Furthermore, the conductive substrate is FTO conductive glass.

[0009] Furthermore, the electron transport layer is a SnO2 electron transport layer, and the SnO2 layer thickness is 3-50nm. The preparation process of the SnO2 electron transport layer is as follows: take a 15wt% SnO2 nanocrystal dispersion liquid purchased, dilute it, spin-coat it on a conductive substrate, and dry it at 100℃~150℃ to obtain;

[0010] Furthermore, the perovskite light-absorbing layer is a mono-, di- or ternary cationic perovskite active layer film, and the thickness of the perovskite light-absorbing layer film is 100 to 1000 nm. The solute of the perovskite precursor solution includes at least one of lead iodide (PbI2), cesium iodide (CsI), lead bromide (PbBr2), methylammonium iodide (MAI), formamidinium iodide (FAI), methylammonium bromide (MABr), and methylammonium chloride (MACl). The solvent of the perovskite precursor solution is at least one of dimethyl sulfoxide (DMSO), NN dimethylformamide (DMF) and N-methylpyrrolidone (NMP). The configured perovskite precursor solution is scraped or spin-coated onto the electron transport layer, and annealed to obtain a perovskite light-absorbing layer;

[0011] Furthermore, the carbon electrode is prepared on the perovskite layer by scraping, and its thickness is 5-50 μm.

[0012] The present invention has the following beneficial effects: The present invention provides a simple method to obtain a carbon electrode with excellent electrical properties. The perovskite battery made by using the composite carbon electrode has better performance than the device made by non-doped carbon slurry, especially the photoelectric conversion efficiency and long-term stability are significantly improved. After being placed in an air environment for 30 days, it still maintains 97% of the initial efficiency. This is because the carbon electrode doped with copper phthalocyanine has a significantly improved hole extraction ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the preparation process of the solar cell of Example 1.

[0014] Figure 2 It is a structural diagram of a solar cell made by the present invention. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments and drawings, but the protection scope of the present invention is not limited thereto.

[0016] Comparative Example 1:

[0017] 1) Cleaning of FTO conductive substrate. Ultrasonic cleaning of FTO glass was performed with acetone, ethylene glycol, and deionized water for 15 min each, blown dry with nitrogen, and placed in a plasma cleaning machine for 15 min to remove residual organic impurities and enhance the wettability of the substrate to the solution;

[0018] 2) Preparation of SnO2 electron transport layer. Dilute the purchased SnO2 nanocrystal dispersion with an equal volume of deionized water with a mass fraction of 15%, drop it on the FTO in step (1), control the gap between the blade and the substrate to be 150μm, scrape at a speed of 10mm / s, and then heat on a hot plate at 150℃ for 30min to obtain a SnO2 electron transport layer;

[0019] 3) Preparation of perovskite active layer. 500mg of PbI2, 175mg of FAI, 20mg of MABr, and 72mg of PbBr2 powder were dissolved in a mixed solution of DMF (900μL) and DMSO (100μL) and stirred thoroughly. Then 5mg of CsI was added to the above solution and stirred for two hours to obtain a mixed cation perovskite precursor solution. 200μL of perovskite precursor solution was dropped on the 50mm*50mm SnO2 electron transport layer, the gap between the blade and the substrate was controlled to be 200μm, and the coating was carried out at a speed of 3mm / s. Then annealed at 150℃ for 15min to crystallize the perovskite.

[0020] 4) Preparation of carbon electrode layer: The purchased untreated carbon slurry was scraped onto the perovskite layer prepared in 3), and heated at 120° C. for 20 minutes to obtain a carbon-based perovskite solar cell.

[0021] Embodiment 1:

[0022] A carbon electrode perovskite solar cell and a preparation method thereof, the process is as follows:

[0023] 1) Cleaning of FTO conductive substrate. Ultrasonic cleaning of FTO glass was performed with acetone, ethylene glycol, and deionized water for 15 min each, blown dry with nitrogen, and placed in a plasma cleaning machine for 15 min to remove residual organic impurities and enhance the wettability of the substrate to the solution;

[0024] 2) Preparation of SnO2 electron transport layer. Dilute the purchased SnO2 nanocrystal dispersion with an equal volume of deionized water with a mass fraction of 15%, drop it on the FTO in step (1), control the gap between the blade and the substrate to be 150μm, scrape at a speed of 10mm / s, and then heat on a hot plate at 150℃ for 30min to obtain a SnO2 electron transport layer;

[0025] 3) Preparation of perovskite active layer. 500 mg of PbI2, 175 mg of FAI, 20 mg of MABr, and 72 mg of PbBr2 powder were dissolved in a mixed solution of DMF (900 μL) and DMSO (100 μL) and stirred thoroughly. Then 5 mg of CsI was added to the above solution and stirred for two hours to obtain a mixed cation perovskite precursor solution. 200 μL of the perovskite precursor solution was dropped on the 50 mm*50 mm SnO2 electron transport layer, the gap between the blade and the substrate was controlled to be 200 μm, and the coating was carried out at a speed of 3 mm / s. Then annealed at 150 ° C for 15 min to crystallize the perovskite.

[0026] 4) Preparation of carbon electrode layer: A carbon slurry doped with 3% copper phthalocyanine was scraped onto the perovskite layer prepared in 3), and heated at 120° C. for 20 minutes to obtain a carbon-based perovskite solar cell.

[0027] Comparative Example 2:

[0028] 1) Cleaning of FTO conductive substrate. Ultrasonic cleaning of FTO glass was performed with acetone, ethylene glycol, and deionized water for 15 min each, blown dry with nitrogen, and placed in a plasma cleaning machine for 15 min to remove residual organic impurities and enhance the wettability of the substrate to the solution;

[0029] 2) Preparation of SnO2 electron transport layer. Dilute the purchased SnO2 nanocrystal dispersion with an equal volume of deionized water with a mass fraction of 15%, drop it onto the FTO in step (1), spin-coat at a speed of 3000 rpm for 30 seconds, and then heat on a hot plate at 150°C for 30 minutes to obtain a SnO2 electron transport layer;

[0030] 3) Preparation of perovskite active layer. 500 mg of PbI2, 175 mg of FAI, 20 mg of MABr, and 72 mg of PbBr2 powder were dissolved in a mixed solution of DMF (900 μL) and DMSO (100 μL) and stirred thoroughly. Then 5 mg of CsI was added to the above solution and stirred for two hours to obtain a mixed cation perovskite precursor solution. 70 μL of the perovskite precursor solution was dropped on the 20 mm*20 mm SnO2 electron transport layer, and the solution was spin-coated at 1000 rpm for 5 s and 5000 rpm for 25 s. At 15 s, 100 μL of chlorobenzene antisolvent was added. Then annealed at 150 ° C for 15 min to crystallize the perovskite.

[0031] 4) Preparation of carbon electrode layer: The purchased untreated carbon slurry was scraped onto the perovskite layer prepared in 3), and heated at 120° C. for 20 minutes to obtain a carbon-based perovskite solar cell.

[0032] Embodiment 2:

[0033] 1) Cleaning of FTO conductive substrate. Ultrasonic cleaning of FTO glass was performed with acetone, ethylene glycol, and deionized water for 15 min each, blown dry with nitrogen, and placed in a plasma cleaning machine for 15 min to remove residual organic impurities and enhance the wettability of the substrate to the solution;

[0034] 2) Preparation of SnO2 electron transport layer. Dilute the purchased SnO2 nanocrystal dispersion with an equal volume of deionized water with a mass fraction of 15%, drop it onto the FTO in step (1), spin-coat at a speed of 3000 rpm for 30 seconds, and then heat on a hot plate at 150°C for 30 minutes to obtain a SnO2 electron transport layer;

[0035] 3) Preparation of perovskite active layer. 500 mg of PbI2, 175 mg of FAI, 20 mg of MABr, and 72 mg of PbBr2 powder were dissolved in a mixed solution of DMF (900 μL) and DMSO (100 μL) and stirred thoroughly. Then 5 mg of CsI was added to the above solution and stirred for two hours to obtain a mixed cation perovskite precursor solution. 70 μL of the perovskite precursor solution was dropped on the 20 mm*20 mm SnO2 electron transport layer, and the solution was spin-coated at 1000 rpm for 5 s and 5000 rpm for 25 s. At 15 s, 100 μL of chlorobenzene antisolvent was added. Then annealed at 150 ° C for 15 min to crystallize the perovskite.

[0036] 4) Preparation of carbon electrode layer: A carbon slurry doped with 3% copper phthalocyanine was scraped onto the perovskite layer prepared in 3), and heated at 120° C. for 20 minutes to obtain a carbon-based perovskite solar cell.

[0037] The structure of the perovskite solar cell prepared by the present invention is shown in FIG. Figure 2 As shown, the photoelectric conversion efficiency of the carbon-based perovskite solar cells prepared in the embodiment and the comparative example was tested under a standard simulated sunlight by an electrochemical workstation, with a voltage scanning range of 0-1.2V and a scanning rate of 100mV / s.

[0038] The photoelectric conversion efficiency of carbon-based perovskite solar cells is as follows (%):

[0039]

[0040] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A carbon electrode perovskite solar cell and a method for preparing the same, characterized in that: From bottom to top, it includes conductive glass, an electron transport layer, a perovskite active layer, and a composite carbon electrode; the composite carbon electrode is a carbon electrode doped with copper phthalocyanine.

2. The perovskite solar cell according to claim 1, characterized in that The composite carbon electrode is prepared by scraping a carbon slurry doped with copper phthalocyanine, wherein the doping amount of copper phthalocyanine in the carbon slurry is 1-5 wt%.

3. The perovskite solar cell according to claim 1 or 2, characterized in that the perovskite light-absorbing layer is a mono-, di- or ternary cation perovskite active layer.

4. The perovskite solar cell according to claim 1 or 2, characterized in that the conductive glass is FTO conductive glass, and the electron transport layer is a composite electron transport layer of one or more of SnO2, TiO2, and ZnO.

5. A method for preparing a perovskite solar cell according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: The conductive substrate is ultrasonically cleaned in acetone, isopropanol, and deionized water for 15 minutes each, and then blown dry with nitrogen for later use. Step 2, preparing an electron transport layer on a conductive substrate; Step 2, preparing a perovskite light absorbing layer on the electron transport layer; Step 3: scrape and coat a carbon electrode on the perovskite light-absorbing layer.

6. The method for preparing a perovskite solar cell according to claim 5, characterized in that: Satisfy at least one of the conditions (1)-(5): (1) In step 1, the conductive substrate is laser etched or etched with dilute hydrochloric acid and zinc powder before cleaning, and is cleaned with a plasma cleaner for 15 minutes before use. (2) Step 2 comprises: spin coating or scraping coating the electron transport layer solution onto a conductive substrate, and annealing; (3) Step 3 comprises: preparing a perovskite precursor solution, and spin coating or scraping the solution onto the electron transport layer, and annealing the solution; (4) Step 4 includes: thoroughly mixing a certain amount of copper phthalocyanine and commercial carbon slurry, coating the mixture on the perovskite active layer, and annealing the mixture.

7. The method for preparing a carbon-based perovskite solar cell according to claim 6, characterized in that: The conductive substrate is FTO, ITO conductive glass or PET flexible conductive substrate, and the solute of the perovskite precursor solution includes at least one of PbI2, PbBr2, PbCl2, CsI, MAI, FAI, MABr and MACl.

8. The method for preparing a carbon-based perovskite solar cell according to claim 7, characterized in that: The solvent of the perovskite precursor solution is at least one of DMF (NN dimethylformamide), DMSO (dimethyl sulfoxide) and NMP (N-methylpyrrolidone).

9. The method for preparing a carbon-based perovskite solar cell according to any one of claims 6 to 8, characterized in that: The thickness of the carbon electrode is 5-50 μm.

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