Carbon-based organic-inorganic perovskite solar cell based on modification of 2-methylthio-1-ethylamine hydrochloride

Abstract

The invention relates to a carbon-based organic-inorganic perovskite solar cell based on modification of 2-methylthio-1-ethylamine hydrochloride and a preparation method of the carbon-based organic-inorganic perovskite solar cell based on modification of 2-methylthio-1-ethylamine hydrochloride. The solar cell sequentially comprises a transparent conductive substrate, an electron transport layer, a perovskite layer, a 2-methylthio-1-ethylamine hydrochloride modification layer and a carbon electrode from bottom to top, the thickness of the 2-methylthio-1-ethylamine hydrochloride modification layer ranges from 5 nm to 10 nm. The preparation method is efficient, the preparation process is simple, the carrier transport performance of the prepared perovskite solar cell based on the carbon electrode is improved, the photoelectric conversion efficiency is remarkably improved, and the perovskite solar cell has good application prospects in the future.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor optoelectronic materials and devices, and particularly relates to a carbon-based organic-inorganic perovskite solar cell modified with 2-methylthio-1-ethylamine hydrochloride. Background Art

[0002] With the continuous consumption of fossil energy, energy crises and environmental problems have become increasingly prominent, attracting extensive attention from countries around the world. As a new type of energy, solar energy mainly converts light energy into electrical energy through the method of photoelectric conversion, and has multiple advantages such as environmental protection, rich resources, and clean and renewable. Due to the advantages of high light absorption coefficient, long carrier lifetime, and simple preparation process of perovskite solar cells (PSCs), they have become the focus of research on the new generation of solar cells.

[0003] Among all the studies on perovskite solar cell devices, carbon materials are considered the most promising electrode materials because carbon materials have rich reserves, low prices, good work function matching, and stable properties, which contribute to improving the performance of PSCs. However, when using carbon electrodes in perovskite solar cells, there will be poor contact at the perovskite / carbon electrode interface, reducing the interfacial carrier transport performance. The carrier transport layer is located between the perovskite active layer and the electrode and is an interfacial layer used to promote charge transport. Therefore, an interface modification method needs to be proposed to improve the carrier transport layer, build a transport bridge between the two layers, and make it have high electron affinity, high electron mobility, good energy level matching, etc. Among the existing interface modification materials, 2-methylthio-1-ethylamine hydrochloride has prominent advantages such as improved adhesion, optimized energy level matching, and enhanced charge transport.

[0004] Currently, most interface modifications use organic or inorganic modifiers to improve the stability of perovskite materials, reduce the defects at grain boundaries in perovskite thin films, and improve the efficiency of the battery. For example, Patent CN115394924A uses trifluoromethylbenzene-based materials as modifiers, such as 4-amino-2-trifluoromethylbenzonitrile, 4-chloro-2-trifluoromethylbenzonitrile, etc. These materials can be spin-coated on the upper interface of the perovskite layer to effectively passivate the uncoordinated ions on the perovskite surface, enabling more effective extraction and transport of carriers at the interface, improving the photoelectric conversion efficiency of perovskite solar cells, and protecting the perovskite layer through the F-containing passivation layer, enhancing the stability of the device. However, in this process, due to the strong electron-withdrawing ability of trifluoromethylbenzene-based materials, the growth of perovskite crystals in the perovskite layer is easily affected by coordinating ions, thereby promoting the nucleation and growth of perovskite crystals with the (110) orientation. The perovskite crystals with the (110) crystal orientation have a high exciton binding energy, which is not conducive to the generation of carriers and affects the performance of the device.

[0005] Therefore, it is crucial to find a material that can passivate the defects of perovskite films efficiently and multifunctionally. Summary of the Invention

[0006] The object of the present invention is to address the limitations of current technologies, solve the problems of poor contact at the perovskite / carbon electrode interface and the cumbersome modification process in carbon electrode perovskite solar cells, and propose a carbon-based organic-inorganic perovskite solar cell modified with 2-methylthio-1-ethylamine hydrochloride. The 2-methylthio-1-ethylamine hydrochloride modification layer can not only form coordination bonds with metal ions in the perovskite layer to fill the defects on the perovskite surface, but also regulate the acid-base environment on the perovskite surface, promote the uniform crystallization of the perovskite film, control the growth of perovskite crystals, and improve the battery stability and photoelectric conversion efficiency. The preparation method of the present invention is efficient and the preparation process is simple. Based on this, the carrier transport performance of the carbon electrode perovskite solar cell is improved, and the photoelectric conversion efficiency is significantly enhanced, showing good application prospects in the future.

[0007] To solve the above technical problems, the technical solution of the present invention is as follows:

[0008] A carbon-based organic-inorganic perovskite solar cell modified with 2-methylthio-1-ethylamine hydrochloride, which sequentially comprises a transparent conductive substrate, an electron transport layer, a perovskite layer, a 2-methylthio-1-ethylamine hydrochloride modification layer, and a carbon electrode from bottom to top;

[0009] The thickness of the 2-methylthio-1-ethylamine hydrochloride modification layer is 5-10 nm.

[0010] The transparent conductive substrate is preferably one of fluorine-doped tin oxide transparent conductive glass (FTO), indium tin oxide transparent conductive glass (ITO), PET / ITO (PET is polyethylene terephthalate), and PEN / ITO (PEN is polyethylene naphthalate);

[0011] The electron transport layer is at least one of tin dioxide (SnO2), titanium dioxide (TiO2), chlorine-doped titanium dioxide, fullerene (C 60 ), [6,6]-phenyl C61 butyric acid methyl ester (PCBM), zinc oxide (ZnO), TiO2-SnO2, ZnO-TiO2, ZnO-SnO2; and the thickness is 5-180 nm;

[0012] The structural formula of the perovskite layer material is APbX3, where the A site is at least one of formamidinium cation (NH2CH=NH2 + , FA + ) and methylammonium cation (CH3NH 3+ , MA + ); and the X site is F -, Cl - , Br - and I - at least one of; the thickness is 200 - 1000 nm;

[0013] The carbon electrode material described is carbon paste, the sheet resistance < 30 Ω, and the solid content is 40 - 60%; the thickness is 5 - 100 μm.

[0014] The preparation method of the 2 - (methylthio)ethylamine hydrochloride - modified carbon - based organic - inorganic perovskite solar cell, this method includes the following steps:

[0015] 1) Prepare an electron transport layer on a transparent conductive substrate;

[0016] 2) Spin - coat a perovskite precursor solution on the electron transport layer, and after treatment with a low - pressure auxiliary device, perform annealing to obtain a perovskite layer;

[0017] The solvent of the perovskite precursor solution is at least one of N,N - dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N - methylpyrrolidone (NMP), dimethylacetamide (DMAc), acetonitrile (MeCN), methylammonium acetate, methylammonium formate, methylammonium butyrate, γ - butyrolactone, anhydrous ethanol;

[0018] The concentration of the perovskite precursor solution is 0.2 - 2 mol / L, and the concentration is calculated based on the content of Pb;

[0019] 3) Spin - coat a 2 - (methylthio)ethylamine hydrochloride solution on the surface of the perovskite light - absorbing layer, and perform annealing treatment to obtain a 2 - (methylthio)ethylamine hydrochloride modification layer;

[0020] The concentration of the 2 - (methylthio)ethylamine hydrochloride solution is 0.7 - 5 mg / mL; the spin - coating speed is 1000 - 6000 rpm, and the spin - coating time is 10 - 60 s; the annealing temperature is 100 - 120 °C, and the treatment time is 5 - 20 min;

[0021] The spin - coating amount is 10 - 200 μL / 4 - 25 cm 2 ;

[0022] 4) Knife - coat carbon paste on the surface of the modification layer, and then perform annealing treatment to finally obtain a carbon - electrode perovskite solar cell on the perovskite upper interface modified with 2 - (methylthio)ethylamine hydrochloride.

[0023] In step 2), the spin coating speed is 1000 - 6000 rpm, and the spin coating time is 10 - 60 s; when the low-pressure auxiliary device is processing, the vacuum degree is 1 - 100 Pa, and the processing time is 1 - 60 s; the annealing temperature is 100 - 120 °C, and the processing time is 5 - 20 min;

[0024] In step 3), the preparation method of the 2-methylthio-1-ethylamine hydrochloride solution is to add 2-methylthio-1-ethylamine hydrochloride to isopropanol to obtain an isopropanol solution of 2-methylthio-1-ethylamine hydrochloride;

[0025] In step 4), the annealing temperature is 100 - 120 °C, and the processing time is 15 - 20 min; the carbon paste has a sheet resistance < 30 Ω and a solid content of 40 - 60%.

[0026] The substantial features of the present invention are:

[0027] In the current technology, to reduce the defects in perovskite solar cells, it mainly starts from two aspects: reducing the uncoordinated ions in perovskite and improving the crystal structure of perovskite. For example, the trifluoromethylbenzene-based materials used in patent CN115394924A spin-coat 4-amino-2-trifluoromethylbenzonitrile, 4-chloro-2-trifluoromethylbenzonitrile, etc. on the upper interface of the perovskite layer. Through the combination of the cyano group (-CN) with the free lead ions (Pb 2+ ) on the perovskite surface, a coordination bond is formed, thus playing a passivation effect, enabling more effective extraction and transport of carriers at the interface. In addition, fluoride ions can not only form Pb-F chemical bonds with unpaired lead ions to passivate defects, but also such F-containing materials have extremely low chemical energy and can form a hydrophobic barrier, thereby inhibiting the penetration of moisture and oxygen into the perovskite layer and further improving the stability of the device.

[0028] The present invention uses the Lewis base 2-methylthio-1-ethylamine hydrochloride. Since the sulfur atom (-SCH3) in it has a lone pair of electrons, it can coordinate with Pb in perovskite 2+ ions. This coordination forms an S-Pb chemical bond, thus effectively passivating the uncoordinated Pb 2+ ions on the perovskite surface and grain boundaries, reducing the defect state density; the amino group (-NH3 + ) and chloride ions (Cl - ) combine with the I - ions on the perovskite surface, reducing the migration of halogen ions, thereby playing a role in passivating defects. At the same time, 2-methylthio-1-ethylamine hydrochloride can also preferentially adsorb on the (100) plane of perovskite through the amino group (-NH3 + ) to reduce its surface energy, induce the preferential (100) orientation growth of perovskite, and further improve the device efficiency and enhance the battery performance.

[0029] In addition, the -SCH3 in 2-methylthio-1-ethylamine hydrochloride regulates the work function of perovskite through surface dipoles, optimizes the energy level matching between the perovskite layer and the carbon electrode layer to a certain extent, reduces the carrier transport barrier, plays a multi-functional passivation role in many aspects, and further improves the device efficiency.

[0030] The beneficial effects of the present invention are as follows:

[0031] 1) A carbon-based organic-inorganic perovskite solar cell modified with 2-methylthio-1-ethylamine hydrochloride provided by the present invention has a simple preparation process, convenient operation, and low cost. As shown in the attached Figure 2 figure, under the condition of indoor non-encapsulation, after storing for 7 days, the efficiency before modification is 97.3% of the initial value, while the efficiency after modification is 90.5% of the initial value. The adopted modification process improves the overall stability of the device by 7.51%, and the stability improvement is obvious;

[0032] 2) Compared with the standard sample not modified with 2-methylthio-1-ethylamine hydrochloride, the interface defects between the perovskite layer and the carbon electrode layer are reduced, the number of non-radiative recombinations of carriers is reduced, the lifetime is increased, and the carrier transport performance is higher. Compared with the comparative example, the open-circuit voltage is increased by 23.50%, the fill factor is increased by 3.74%, and the photoelectric conversion efficiency is increased by 24.43%. In this technology, an isopropanol solution of 2-methylthio-1-ethylamine hydrochloride is used for drop-coating modification of the interface between the perovskite layer and the carbon electrode layer. The sulfur atom (-SCH3), amino group (-NH3 + ) and chloride ion (Cl - ) in it form coordination bonds with the free lead ions and iodide ions in the perovskite layer, which can effectively passivate the defects of the perovskite layer. In addition, 2-methylthio-1-ethylamine hydrochloride, as a Lewis base, effectively regulates the acid-base environment of the perovskite layer, further reduces the non-radiative recombination at the interface, and improves the stability and efficiency of the device. At the same time, the sulfur atom (-SCH3) plays a role in regulating the growth of perovskite crystals and optimizing the energy level matching, and modifies the perovskite layer efficiently and multifunctionally, thereby improving the battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic structural diagram of the solar cell of Example 1; wherein, 1 is a transparent conductive substrate, 2 is an electron transport layer, 3 is a perovskite layer, 4 is a 2-methylthio-1-ethylamine hydrochloride modification layer, and 5 is a carbon electrode;

[0034] Figure 2 It is the stability test curve of the carbon electrode perovskite solar cell device obtained in Example 1 and Example 16 (comparative example);

[0035] Figure 3J-V test curve graphs of the carbon electrode perovskite solar cell devices obtained in Example 1 and Example 16 (comparative example). Detailed implementation manners

[0036] The 2-methylthio-1-ethylamine hydrochloride involved in the present invention is a well-known material. In the following examples, it is sourced from Shanghai Aladdin Biochemical Technology Co., Ltd. and Beijing Innochem Technology Co., Ltd.; however, it is not limited thereto;

[0037] Example 1.

[0038] A carbon electrode perovskite solar cell based on a 2-methylthio-1-ethylamine hydrochloride solution modified on the upper interface of the perovskite. The schematic diagram of the structure of this solar cell is as Figure 1 shown. From bottom to top, it is a transparent conductive substrate 1, an electron transport layer 2, a perovskite layer 3, a 2-methylthio-1-ethylamine hydrochloride modification layer 4, and a carbon electrode 5. The specific preparation process is as follows:

[0039] Step 1. Clean the FTO substrate:

[0040] The commercial FTO (2.5 cm × 2.5 cm) transparent conductive substrate used in this example has an average light transmittance of 90%. The FTO substrate is ultrasonically cleaned with glass cleaning agent, deionized water, and alcohol for 30 minutes in sequence, and then dried with a nitrogen gun.

[0041] Step 2. Prepare the SnO2 electron transport layer:

[0042] Weigh 625 mg of urea and 137.5 mg of SnCl2·2H2O with a balance and put them into a blue-mouth bottle. Then, successively add 625 μL of HCl, 12.5 μL of TGA, and 50 mL of deionized water with a pipette gun, and mix evenly to obtain the SnO2 growth solution for standby.

[0043] Immerse the cleaned FTO substrate into the staining dish filled with the SnO2 growth solution, place it in an oven at 90 °C for 4 hours, and then take it out. Ultrasonically clean it with deionized water for 5 minutes, and then dry its surface with a nitrogen gun; then perform annealing treatment (annealing temperature 170 °C, annealing time 60 minutes), and finally obtain the electron transport layer SnO2; the thickness is 30 nm.

[0044] Step 3. Prepare the FA 0.3 MA 0.7 PbI3 perovskite layer:

[0045] Prepare 1.33 mol / L FA 0.3 MA 0.7PbI3 perovskite precursor solution, with the concentration calculated based on the lead content, specifically including solutes formamidinium iodide (FAI), methylammonium iodide (MAI), and lead iodide (PbI2), with molar amounts of 0.36 mmol, 0.84 mmol, and 1.2 mmol respectively. 100 μL of NMP and 800 μL of DMF are successively added as solvents to obtain 900 μL of perovskite precursor solution.

[0046] Using a spin coater, spin coat the prepared perovskite precursor solution on the SnO2 electron transport layer. First, spin coat at 2500 rpm for 10 s, then at 4500 rpm for 10 s, and then immediately place it in a low-pressure auxiliary system (DL-10A type quartz vacuum gauge and vacuum pump) for low-pressure (vacuum degree of 10 Pa) treatment for 60 s to quickly volatilize the solvent, thereby obtaining a well-crystallized intermediate phase film. After the low-pressure treatment, anneal on a heating table at 120 °C for 20 min to obtain a well-crystallized perovskite film. Among them, the volume of the spin-coated perovskite precursor is 60 μL; the thickness is 600 nm.

[0047] Step 4: Prepare a 2-methylthio-1-ethylamine hydrochloride modification layer:

[0048] Weigh 2 mg of 2-methylthio-1-ethylamine hydrochloride with an electronic balance and add it to a reagent glass bottle, then add 1 mL of isopropanol to obtain an isopropanol solution with a concentration of 2 mg / mL. Place the annealed device from the previous step on the spin coater for adsorption. After dropping 100 μL on the perovskite light-absorbing layer, then spin at 4000 rmp for 30 s, and then anneal at 100 °C for 10 min; the thickness is 5 nm.

[0049] Step 5: Prepare a carbon electrode:

[0050] Attach two 3M tapes on the surface of the perovskite layer to control the thickness of the carbon electrode, leaving a rectangular gap with a width of 0.3 cm and a length of 2.5 cm in the middle. Take 50 mg of low-temperature carbon paste (sheet resistance < 30 ohms, solid content of 50%, cleaning agent is cyclohexanone, CAS number is 7440-44-0. The same applies to the following examples and will not be repeated) and put it into the gap, and scrape it multiple times in the same direction with a blade until the gap is completely filled. The area of the scraped carbon electrode is 0.3 cm × 2.5 cm, and then anneal on a heating table at 100 °C for 15 min; the thickness is 10 μm.

[0051] In this example, four measurement points are randomly selected for a single-carbon-electrode perovskite solar cell, and the effective area of each measurement point is 0.075 cm 2 .

[0052] In this embodiment, a solar simulator was used to select a K-2400 light source to simulate AM 1.5G illumination for J-V testing of a perovskite solar cell with a carbon electrode on the upper interface of a perovskite light-absorbing layer modified with 2-methylthio-1-ethylamine hydrochloride. As Figure 3 shown by the solid line in 2 , the photoelectric conversion efficiency of the solar cell was 14.41% as obtained from the J-V curve. The open-circuit voltage, short-circuit current density, and fill factor were 1.03 V, 24.24 mA / cm 2 and 59.79% respectively.

[0053] In this embodiment, a solar simulator was used to select a K-2400 light source to simulate AM 1.5G illumination for a 7-day tracking test on the stability of the photoelectric conversion efficiency of a perovskite solar cell with a carbon electrode on the upper interface of a perovskite light-absorbing layer modified with 2-methylthio-1-ethylamine hydrochloride. As Figure 2 shown by the solid line in

[0054] Example 2:

[0055] For a perovskite solar cell with a carbon electrode on the upper interface of perovskite modified with an isopropanol solution of 2-methylthio-1-ethylamine hydrochloride, other steps were the same as in Example 1, and the differences were:

[0056] In the preparation of the isopropanol solution of 2-methylthio-1-ethylamine hydrochloride in Step 3, 0.7 mg of 2-methylthio-1-ethylamine hydrochloride was added to 1 mL of isopropanol, and the concentration was 0.7 mg / mL.

[0057] Example 3:

[0058] For a perovskite solar cell with a carbon electrode on the upper interface of perovskite modified with an isopropanol solution of 2-methylthio-1-ethylamine hydrochloride, other steps were the same as in Example 1, and the differences were:

[0059] In the preparation of the isopropanol solution of 2-methylthio-1-ethylamine hydrochloride in Step 3, 1 mg of 2-methylthio-1-ethylamine hydrochloride was added to 1 mL of isopropanol, and the concentration was 1 mg / mL.

[0060] Example 4:

[0061] For a perovskite solar cell with a carbon electrode on the upper interface of perovskite modified with an isopropanol solution of 2-methylthio-1-ethylamine hydrochloride, other steps were the same as in Example 1, and the differences were:

[0062] In the preparation of the isopropanol solution of 2-methylthio-1-ethylamine hydrochloride in Step 3, 3 mg of 2-methylthio-1-ethylamine hydrochloride was added to 1 mL of isopropanol, and the concentration was 3 mg / mL.

[0063] Example 5:

[0064] For the perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-methylthio-1-ethylamine hydrochloride on the upper interface of the perovskite, the other steps are the same as those in Example 1, except that:

[0065] In the preparation of the isopropanol solution of 2-methylthio-1-ethylamine hydrochloride in Step 3, 4 mg of 2-methylthio-1-ethylamine hydrochloride was added to 1 mL of isopropanol, and the concentration was 4 mg / mL.

[0066] Example 6:

[0067] For the perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-methylthio-1-ethylamine hydrochloride on the upper interface of the perovskite, the other steps are the same as those in Example 1, except that:

[0068] In the preparation of the isopropanol solution of 2-methylthio-1-ethylamine hydrochloride in Step 3, 5 mg of 2-methylthio-1-ethylamine hydrochloride was added to 1 mL of isopropanol, and the concentration was 5 mg / mL.

[0069] Example 7.

[0070] For the perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-methylthio-1-ethylamine hydrochloride on the upper interface of the perovskite, the other steps are the same as those in Example 1, except that:

[0071] In the preparation of the perovskite layer in Step 4, the perovskite layer is FAPbI3 with a concentration of 1.33 mol / L, which is based on the content of lead. Specifically, the solutes are formamidinium iodide, lead iodide, and methylammonium chloride, and the molar amounts are 1.2 mmol, 1.2 mmol, and 0.18 mmol respectively. 100 μL of NMP and 800 μL of DMF were added in sequence as solvents to obtain 900 μL of the perovskite precursor solution.

[0072] Example 8.

[0073] For the perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-methylthio-1-ethylamine hydrochloride, the other steps are the same as those in Example 1, except that:

[0074] In the preparation of the perovskite layer in Step 4, the perovskite layer is MAPbI3 with a concentration of 1.33 mol / L, which is based on the content of lead. Specifically, the solutes are methylammonium iodide, lead iodide, and methylammonium chloride, and the molar amounts are 1.2 mmol, 1.2 mmol, and 0.18 mmol respectively. 100 μL of NMP and 800 μL of DMF were added in sequence as solvents to obtain 900 μL of the perovskite precursor solution.

[0075] Example 9.

[0076] For the perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-(methylthio)ethanamine hydrochloride on the upper interface of the perovskite, other steps are the same as in Example 1, except that:

[0077] In Step 4, for the preparation of the perovskite layer, the perovskite layer is FA 0.85 MA 0.15 PbI3, with a concentration of 1.33 mol / L in terms of the lead content. Specifically, it includes solutes formamidinium iodide, methylammonium iodide, lead iodide, and methylammonium chloride, with molar amounts of 1.02 mmol, 0.18 mmol, 1.2 mmol, and 0.18 mmol respectively. 100 μL of NMP and 800 μL of DMF are sequentially added as solvents to obtain 900 μL of the perovskite precursor solution.

[0078] Example 10.

[0079] For the perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-(methylthio)ethanamine hydrochloride on the upper interface of the perovskite, other steps are the same as in Example 1, except that:

[0080] In Step 3, for the preparation of the isopropanol solution of 2-(methylthio)ethanamine hydrochloride, 2 mg of 2-(methylthio)ethanamine hydrochloride is added to 1 mL of isopropanol, with a concentration of 2 mg / mL;

[0081] In Step 4, for the preparation of the perovskite layer, the perovskite layer is FA 0.85 MA 0.15 PbI3, with a concentration of 1.33 mol / L in terms of the lead content. Specifically, it includes solutes formamidinium iodide, methylammonium iodide, lead iodide, and methylammonium chloride, with molar amounts of 1.02 mmol, 0.18 mmol, 1.2 mmol, and 0.18 mmol respectively. 100 μL of NMP and 800 μL of DMF are sequentially added as solvents to obtain 900 μL of the perovskite precursor solution.

[0082] Example 11.

[0083] For the perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-(methylthio)ethanamine hydrochloride on the upper interface of the perovskite, other steps are the same as in Example 1, except that:

[0084] In Step 3, for the preparation of the isopropanol solution of 2-(methylthio)ethanamine hydrochloride, 0.7 mg of 2-(methylthio)ethanamine hydrochloride is added to 1 mL of isopropanol, with a concentration of 0.7 mg / mL;

[0085] In Step 4, for the preparation of the perovskite layer, the perovskite layer is FA 0.85 MA0.15 PbI3, with a concentration of 1.33 mol / L, calculated based on the lead content, specifically including solutes formamidinium iodide, methylammonium iodide, lead iodide, and methylammonium chloride, with molar amounts of 1.02 mmol, 0.18 mmol, 1.2 mmol, and 0.18 mmol respectively. 100 μL of NMP and 800 μL of DMF were successively added as solvents to obtain 900 μL of perovskite precursor solution.

[0086] Example 12.

[0087] A perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-methylthio-1-ethylamine hydrochloride on the upper interface of perovskite. Other steps are the same as in Example 1, except that:

[0088] In the preparation of the isopropanol solution of 2-methylthio-1-ethylamine hydrochloride in Step 3, 1 mg of 2-methylthio-1-ethylamine hydrochloride was added to 1 mL of isopropanol, with a concentration of 1 mg / mL;

[0089] In the preparation of the perovskite layer in Step 4, the perovskite layer is FA 0.85 MA 0.15 PbI3, with a concentration of 1.33 mol / L, calculated based on the lead content, specifically including solutes formamidinium iodide, methylammonium iodide, lead iodide, and methylammonium chloride, with molar amounts of 1.02 mmol, 0.18 mmol, 1.2 mmol, and 0.18 mmol respectively. 100 μL of NMP and 800 μL of DMF were successively added as solvents to obtain 900 μL of perovskite precursor solution.

[0090] Example 13.

[0091] A perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-methylthio-1-ethylamine hydrochloride on the upper interface of perovskite. Other steps are the same as in Example 1, except that:

[0092] In the preparation of the isopropanol solution of 2-methylthio-1-ethylamine hydrochloride in Step 3, 3 mg of 2-methylthio-1-ethylamine hydrochloride was added to 1 mL of isopropanol, with a concentration of 3 mg / mL;

[0093] In the preparation of the perovskite layer in Step 4, the perovskite layer is FA 0.85 MA 0.15 PbI3, with a concentration of 1.33 mol / L, calculated based on the lead content, specifically including solutes formamidinium iodide, methylammonium iodide, lead iodide, and methylammonium chloride, with molar amounts of 1.02 mmol, 0.18 mmol, 1.2 mmol, and 0.18 mmol respectively. 100 μL of NMP and 800 μL of DMF were successively added as solvents to obtain 900 μL of perovskite precursor solution.

[0094] Example 14.

[0095] For the perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-(methylthio)ethanamine hydrochloride on the perovskite upper interface, other steps are the same as those in Example 1, except that:

[0096] In Step 3, for the preparation of the isopropanol solution of 2-(methylthio)ethanamine hydrochloride, 4 mg of 2-(methylthio)ethanamine hydrochloride was added to 1 mL of isopropanol, and the concentration was 4 mg / mL;

[0097] In Step 4, for the preparation of the perovskite layer, the perovskite layer was FA 0.85 MA 0.15 PbI3, with a concentration of 1.33 mol / L, calculated based on the content of lead. Specifically, the solutes were formamidinium iodide, methylammonium iodide, lead iodide, and methylammonium chloride, with molar amounts of 1.02 mmol, 0.18 mmol, 1.2 mmol, and 0.18 mmol, respectively. 100 μL of NMP and 800 μL of DMF were sequentially added as solvents to obtain 900 μL of the perovskite precursor solution.

[0098] Example 15.

[0099] For the perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-(methylthio)ethanamine hydrochloride on the perovskite upper interface, other steps are the same as those in Example 1, except that:

[0100] In Step 3, for the preparation of the isopropanol solution of 2-(methylthio)ethanamine hydrochloride, 5 mg of 2-(methylthio)ethanamine hydrochloride was added to 1 mL of isopropanol, and the concentration was 5 mg / mL;

[0101] In Step 4, for the preparation of the perovskite layer, the perovskite layer was FA 0.85 MA 0.15 PbI3, with a concentration of 1.33 mol / L, calculated based on the content of lead. Specifically, the solutes were formamidinium iodide, methylammonium iodide, lead iodide, and methylammonium chloride, with molar amounts of 1.02 mmol, 0.18 mmol, 1.2 mmol, and 0.18 mmol, respectively. 100 μL of NMP and 800 μL of DMF were sequentially added as solvents to obtain 900 μL of the perovskite precursor solution.

[0102] Example 16. (Comparative Example)

[0103] For the perovskite solar cell with a carbon electrode modified by an isopropanol solution of 2-(methylthio)ethanamine hydrochloride on the perovskite upper interface, other steps are the same as those in Example 1, except that:

[0104] Omit the operation in Step 3, without preparing the 2-(methylthio)ethylamine hydrochloride modification layer, and directly scrape the carbon electrode on the surface of the perovskite light-absorbing layer.

[0105] In this embodiment, a solar simulator is used to select the K-2400 light source to simulate AM 1.5G illumination for J-V testing of the perovskite solar cell with the interface between the perovskite layer / carbon electrode layer not modified with 2-(methylthio)ethylamine hydrochloride, as Figure 3 shown by the dashed line in. From the J-V curve, the photoelectric conversion efficiency of the solar cell is 11.58%, and the open-circuit voltage, short-circuit current density, and fill factor are 0.834 V, 23.93 mA / cm 2 and 57.63% respectively.

[0106] In this embodiment, a solar simulator is used to select the K-2400 light source to simulate AM 1.5G illumination for a 7-day tracking test on the stability of the photoelectric conversion efficiency of the perovskite solar cell with the interface between the perovskite layer / carbon electrode layer not modified with 2-(methylthio)ethylamine hydrochloride. As Figure 2 shown by the dashed line in, the photoelectric conversion efficiency after storage for 7 days is 10.48%, which is 90.5% of the initial efficiency.

[0107] Through the comparison of the device test parameters in Example 1 and Example 16 (comparative example), it shows that in the carbon electrode organic-inorganic hybrid perovskite solar cell, introducing a 2-(methylthio)ethylamine hydrochloride modification layer between the perovskite light-absorbing layer and the carbon electrode layer by the drop-coating method can significantly improve the photoelectric conversion efficiency of the device.

[0108] The present invention is not limited to the above embodiments and can be varied within the scope of the claims. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

[0109] Matters not covered by the present invention are well-known technologies.

Claims

1. A carbon-based organic-inorganic perovskite solar cell modified with 2-methylthio-1-ethylamine hydrochloride, characterized in that, The solar cell, from bottom to top, successively comprises a transparent conductive substrate, an electron transport layer, a perovskite layer, a 2-methylthio-1-ethylamine hydrochloride modification layer, and a carbon electrode; The thickness of the described 2-methylthio-1-ethylamine hydrochloride modification layer is 5 - 10 nm.

2. The carbon-based organic-inorganic perovskite solar cell modified with 2-methylthio-1-ethylamine hydrochloride as claimed in claim 1, wherein The described transparent conductive substrate is preferably one of fluorine-doped tin oxide transparent conductive glass (FTO), indium tin oxide transparent conductive glass (ITO), PET / ITO (PET is polyethylene terephthalate), PEN / ITO (PEN is polyethylene naphthalate); The electron transport layer described above is at least one of tin dioxide (SnO2), titanium dioxide (TiO2), chlorine-doped titanium dioxide, fullerene (C 60 ), [6,6]-phenyl C61 butyric acid methyl ester (PCBM), zinc oxide (ZnO), TiO2-SnO2, ZnO-TiO2, ZnO-SnO2; and has a thickness of 5 to 180 nm; The structural formula of the perovskite layer material is APbX3, where the A site is at least one of formamidinium cations (NH2CH=NH2 + , FA + ) and methylammonium cations (CH3NH 3+ , MA + ); the X site is at least one of F - , Cl - , Br - and I - ; and the thickness is 200 - 1000 nm.

3. The carbon-based organic-inorganic perovskite solar cell modified with 2-methylthio-1-ethylamine hydrochloride as claimed in claim 1, characterized in that, The carbon electrode material is carbon paste, with a sheet resistance < 30 Ω, a solid content of 40 - 60%; and a thickness of 5 - 100 μm.

4. The preparation method of the carbon-based organic-inorganic perovskite solar cell modified with 2-methylthio-1-ethylamine hydrochloride, characterized in that, This method comprises the following steps: 1) Prepare an electron transport layer on the transparent conductive substrate; 2) Spin-coat a perovskite precursor solution on the electron transport layer using a spin coater, and after treatment with a low-pressure auxiliary device, perform annealing to obtain a perovskite layer; The solvent of the described perovskite precursor solution is at least one of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), dimethylacetamide (DMAc), acetonitrile (MeCN), methylammonium acetate, methylammonium formate, methylammonium butyrate, γ-butyrolactone, absolute ethanol; The concentration of the described perovskite precursor solution is 0.2 - 2 mol / L, with the concentration calculated based on the content of Pb; 3) Spin-coat a 2-methylthio-1-ethylamine hydrochloride solution on the surface of the perovskite light-absorbing layer, and perform annealing treatment to obtain a 2-methylthio-1-ethylamine hydrochloride modification layer; The concentration of the described 2-methylthio-1-ethylamine hydrochloride solution is 0.7 - 5 mg / mL; the spin-coating speed is 1000 - 6000 rpm, and the spin-coating time is 10 - 60 s; the annealing temperature is 100 - 120 °C, and the treatment time is 5 - 20 min; The spin coating amount is 10 to 200 μL / 4 to 25 cm 2 ; 4) Knife-coat carbon paste on the surface of the modification layer, and then perform annealing treatment to finally obtain a carbon electrode perovskite solar cell based on the upper interface of the perovskite modified with 2-methylthio-1-ethylamine hydrochloride.

5. The preparation method of the carbon-based organic-inorganic perovskite solar cell modified with 2-methylthio-1-ethylamine hydrochloride as claimed in claim 4, characterized in that, In step 3), the solvent of the described 2-methylthio-1-ethylamine hydrochloride solution is isopropyl alcohol.

6. The preparation method of the carbon-based organic-inorganic perovskite solar cell modified by 2-methylthio-1-ethylamine hydrochloride, characterized in that, In step 2), the spin-coating speed is 1000 - 6000 rpm, and the spin-coating time is 10 - 60 s; the vacuum degree during the treatment with the low-pressure auxiliary device is 1 - 100 Pa, and the treatment time is 1 - 60 s; the annealing temperature is 100 - 120 °C, and the treatment time is 5 - 20 min; In step 4), the annealing temperature is 100 - 120 °C, and the treatment time is 15 - 20 min; carbon paste, with a sheet resistance < 30 Ω, and a solid content of 40 - 60%.

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