Broadband-gap perovskite solar cell and preparation method thereof

Abstract

The invention relates to the technical field of solar cells, in particular to a wide-band-gap perovskite solar cell and a preparation method thereof. The preparation method comprises the following steps: preparation of the ITO layer, O2-plasma treatment of the ITO layer, preparation of the hole transport layer, preparation of the perovskite light absorption film layer, coating of PEAI post-treatment salt, preparation of the thermal evaporation C60 electron transport layer, preparation of the SnO2 electron transport layer by an atomic layer deposition method, plating of the ITO transparent conductive electrode by a magnetron sputtering technology, preparation of the metal gate line, and evaporation of the MgF2 antireflection layer. The organic fluorescent material NPBI2 which absorbs ultraviolet light and converts the ultraviolet light into visible light is doped into the perovskite light absorption layer, so that the damage of the ultraviolet light to perovskite is avoided, the perovskite can absorb the visible light to generate power and improve the photoelectric conversion efficiency, and the organic fluorescent material can passivate crystal defects in the perovskite light absorption layer and improve the quality of the perovskite thin film. And the carrier lifetime is prolonged.

Description

Technical Field

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

[0002] Due to its excellent optoelectronic properties, simple preparation process, low cost, etc., perovskite solar cells are considered to be one of the most promising technologies in the new generation of thin-film solar cells. At the same time, the perovskite material can conveniently change its bandgap by adjusting its components, and its preparation methods are also diverse. Therefore, perovskite solar cells are widely used in the preparation of tandem cells to break through the Shockley–Queisser limit (S-Q limit) of single-junction cells and further improve the photoelectric conversion efficiency of solar cells.

[0003] However, ultraviolet light in the solar spectrum has strong destructive effects on perovskite materials, easily causing degradation and phase change of perovskite, resulting in device failure.

[0004] In the existing ultraviolet light absorption technology, the ultraviolet light is directly absorbed, and the solar cell cannot utilize the energy of the ultraviolet light for power generation, reducing the photoelectric conversion efficiency; the light conversion film technology will cause additional process complexity and increase the manufacturing cost of the battery. Therefore, there is an urgent need for a perovskite solar cell that can both avoid the damage of ultraviolet light to perovskite and make full use of the energy of ultraviolet light for power generation. Summary of the Invention

[0005] In order to solve the defects of the existing technology, the present invention provides a wide-bandgap perovskite solar cell and a preparation method thereof.

[0006] The present invention adopts the following technical solutions: A preparation method of a wide-bandgap perovskite solar cell, comprising the following steps: S1: Preparation of ITO layer: Obtain a heterojunction crystalline silicon cell, and deposit ITO on the heterojunction crystalline silicon cell by using magnetron sputtering technology. The sputtering power is 50 - 300 W, the sputtering time is 3 - 30 min, and the thickness of the ITO coating is set to 50 - 150 nm; S2: O2-plasma treatment: Perform O2-plasma treatment for 5 - 15 min to remove residual organic substances on the surface of the transparent conductive substrate and improve the work function; S3: Preparation of hole transport layer: Place the treated sample in a glove box under a nitrogen atmosphere, and prepare a layer of hole transport layer on the sample. The material of the hole transport layer is selected as [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid, and the concentration is 0.1 - 5 mg ml-1 , The solvent is ethanol. The solution is evenly coated using the spin coating method, and the rotation speed is set to 1000 - 10000 rpm. After spin coating, it is transferred to a hot plate at 80 - 150 °C for annealing for 5 - 30 min; S4: Preparation of the perovskite light-absorbing thin film layer: The perovskite precursor material is added to the corresponding solvent in a preset ratio and stirred and oscillated to obtain a perovskite precursor solution. The organic fluorescent material NPBI2 is incorporated into the prepared perovskite precursor solution, and the concentration is 0.5 - 5 mg mL -1 ; An appropriate amount of the mixed solution is spin-coated onto the hole transport layer using a spin coater. The process of dropping the antisolvent chlorobenzene during spin coating includes: The first step: The rotation speed range is selected as 500 - 2000 rpm, and the increasing rate of the rotation speed is 100 - 2000 rpm s -1 , and the time is 10 s; The second step: The rotation speed range is selected as 2000 - 10000 rpm, and the increasing rate of the rotation speed is 1000 - 10000 rpm s -1 , and the time is 30 s; 100 - 3000 ul of chlorobenzene is dropped as the antisolvent at the 25th second. After spin coating, the obtained perovskite light-absorbing layer is placed on a hot plate for annealing. The annealing temperature is 80 °C to 150 °C, and the annealing time is 5 - 90 min to obtain the perovskite light-absorbing thin film layer; S5: Coating the post-treatment salt of PEAI: The selected ammonium salts include at least one of phenyltrimethylammonium salt, benzylammonium salt, tetrabutylammonium salt, and octylammonium salt. The selected solvents include at least one of isopropanol, acetonitrile, chlorobenzene, and chloroform, and are mixed in a preset ratio. The solution concentration is set to 0.5 - 10 mg mL -1 ; An appropriate amount of the mixed solution is spin-coated onto the perovskite light-absorbing thin film layer using a spin coater. The process includes: The spin coating rotation speed range is selected as 1000 - 10000 rpm, the spin coating time is 10 - 90 s. After spin coating, the passivated perovskite light-absorbing layer is placed on a hot plate for annealing. The annealing temperature is 80 - 150 °C, and the annealing time is 5 - 30 min; S6: Preparation of the C60 electron transport layer by thermal evaporation: The passivated perovskite light-absorbing thin film layer is transferred to an organic material evaporation chamber, and the electron transport layer C60 is evaporated, with a thickness of 10 - 50 nm and an evaporation rate of 0.1 - 5 Å s -1 ; S7: Preparation of the SnO2 electron transport layer by atomic layer deposition: Using tetraethyltin as a precursor, deposit 20 - 300 cycles with a thickness of 10 - 60 nm. The specific process is as follows: Precursor introduction: Introduce tetraethyltin into the reaction chamber to adsorb it on the substrate surface; Purge: Use an inert gas to purge the reaction chamber to remove unreacted precursors; Reaction gas introduction: Introduce oxygen to react with the tetraethyltin adsorbed on the substrate to form SnO2; Purge again: Use an inert gas to purge again to remove reaction by-products and unreacted reaction gases; S8: Magnetron sputtering technology for depositing ITO transparent conductive electrodes: Place the sample into the vacuum chamber of a magnetron sputtering coater, adjust the vacuum degree to 10 -4 ~10 -5 Pa. The magnetron sputtering coater deposits an ITO transparent conductive electrode with a thickness of 80 - 150 nm on the SnO2 electron transport layer. Set the sputtering power to 50 - 300 W. The working gas pressure and gas ratio are mainly argon, with a flow rate of 20 - 40 sccm, and the O2 addition amount is 0.5 - 2% to control the oxygen vacancies in the thin film; The substrate temperature ≤ 80°C, and the target-substrate distance is 6 - 10 cm, taking into account both uniformity and particle energy attenuation; Control the deposition rate to 5 - 15 nm / min, with a thickness of 80 - 150 nm, corresponding to a sputtering time of 10 - 30 min, and the total pressure is 0.3 - 1.0 Pa; S9: Preparation of metal grid lines: Evaporate silver metal grid lines in a metal evaporation chamber with a thickness of 60 - 200 nm, and the evaporation rate is 0.1 - 10 Å s -1 , and adopt a stepped rate control; S10: Evaporate the MgF2 antireflection layer: Use a thermal evaporation coating device, place the sample into the vacuum chamber, and adjust the vacuum degree to 10 -4 ~10 -5 Pa, and the evaporation rate is 0.1 - 1 Å s -1 , and evaporate the MgF2 antireflection layer with a thickness of 60 - 200 nm.

[0007] In some embodiments, in S1, the ITO sputtering power is 150 W, the sputtering time is 8 min, and the obtained ITO thickness is 100 nm ± 10 nm.

[0008] In some embodiments, in S3, use [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphoric acid with a concentration of 0.5 mg ml -1 , the solvent is ethanol, the spin-coating process is 3000 rpm for 30 s, and then transfer it to a 100°C hot stage for annealing for 5 min.

[0009] In some embodiments, in S4, at least two of lead iodide, lead chloride, lead bromide, formamidinium iodide, formamidinium chloride, formamidinium bromide, methylammonium iodide, methylammonium chloride, methylammonium bromide, cesium iodide, cesium chloride, cesium bromide, rubidium iodide, rubidium chloride, and rubidium bromide are selected and mixed in a preset ratio; at least two of dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone are selected as solvents and mixed in a preset ratio; a perovskite precursor solution is obtained, and NPBI2 is incorporated into the prepared perovskite precursor solution at a concentration of 1 mg / ml -1 ; Use a spin coater to spin coat an appropriate amount of the mixed solution onto the hole transport layer. The process of dropping an anti-solvent during spin coating includes: The first step: the rotation speed is 2000 rpm and the time is 10 s; the second step: the rotation speed is 5000 rpm and the time is 30 s; 150 μL of chlorobenzene is dropped as an anti-solvent at the 25th second. After spin coating, the obtained perovskite light-absorbing layer is placed on a hot plate for annealing. The annealing temperature is 100°C and the annealing time is 10 min.

[0010] In some embodiments, in S5, a PEAI post-treatment salt is coated. The selected ammonium salt is phenyltrimethylammonium salt. The selected solvent and volume ratio are chlorobenzene:isopropanol = 1:2, and the solution concentration is 1 mg / ml -1 , the spin coating process is 4000 rpm for 30 s, and then annealed at 100°C for 5 min.

[0011] In some embodiments, in S7, tetraethyltin is used as a precursor, and an SnO2 electron transport layer is prepared by a deposition method for 250 cycles with a thickness of 20 nm.

[0012] In some embodiments, in S8, an ITO transparent conductive electrode is deposited by magnetron sputtering technology. The sputtering target is ITO, the sputtering power is 150 W, the sputtering time is 10 min, and the obtained ITO thickness is approximately 120 nm ± 10 nm.

[0013] In some embodiments, in S9, a silver metal grid line is evaporated with a thickness of 60 - 200 nm, and the stepwise rate control is as follows: When the evaporated metal thickness is 0 - 10 nm, the rate is 0.1 Å / s -1 ; when the thickness is 10 - 20 nm, the rate is 0.2 Å / s -1 ; when the thickness is 20 - 30 nm, the rate is 0.3 Å / s -1 ; when the thickness is 30 - 40 nm, the rate is 0.3 Å / s -1 ; when the thickness is 40 - 50 nm, the rate is 0.4 Å / s -1; When the thickness is 50 - 60 nm, the rate is 0.5 Å s -1 ; When the thickness is 60 - 70 nm, the rate is 0.6 Å s -1 ; When the thickness is 70 - 200 nm, the rate is 1 - 10 Å s -1 。

[0014] In some embodiments, in S10, 150 nm of MgF2 is evaporated as an antireflection layer.

[0015] The present invention also discloses a wide - bandgap perovskite solar cell, which is prepared by using the preparation method of the above - mentioned wide - bandgap perovskite solar cell. Beneficial effects

[0016] The present invention discloses a wide - bandgap perovskite solar cell and a preparation method. Compared with the prior art, the present invention has the following advantages: The present invention incorporates a newly designed organic fluorescent material NPBI2 that absorbs ultraviolet light and converts it into visible light into the perovskite light - absorbing layer. While avoiding damage to the perovskite by ultraviolet light, the perovskite can also absorb the emitted visible light and generate electricity, improving the photoelectric conversion efficiency of the battery. There is no need to additionally make a light - conversion film functional layer, simplifying the preparation process steps of the perovskite solar cell. At the same time, the organic fluorescent material in this patent, as an additive, can passivate the crystal defects in the perovskite light - absorbing layer, improve the quality of the perovskite film, increase its carrier lifetime, and improve the photoelectric conversion performance.

[0017] The newly designed organic fluorescent material NPBI2 of the present invention has a dual function of protecting the perovskite film from ultraviolet damage and improving the quality of the perovskite film, thereby improving the photoelectric conversion performance of the perovskite battery or the tandem battery; currently, the photoelectric conversion efficiency of a perovskite - silicon tandem solar cell (target group, Target cell) prepared by doping an organic fluorescent dye molecular material is 30.5% ( Figure 4 as shown), while the highest photoelectric conversion efficiency of a perovskite solar cell (control group, Control cell) prepared without doping an organic fluorescent dye molecular material is 28.1% ( Figure 5 as shown). At the same time, the light - irradiation stability of the perovskite - silicon tandem solar cell prepared by doping an organic fluorescent dye molecular material has also been significantly improved. Description of the drawings

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. These drawings form a part of the present invention. The schematic embodiments of the present invention and their explanations explain the present invention and do not constitute an improper limitation to the present invention; in the drawings: Figure 1Flow chart of the preparation method of a wide-bandgap perovskite solar cell; Figure 2 Block diagram of the structure of a wide-bandgap perovskite solar cell; Figure 3 Schematic diagram of the molecular structure of the organic fluorescent material NPBI2; Figure 4 Volt-ampere characteristic curve of the Target cell of a perovskite-silicon tandem solar cell prepared by doping an organic fluorescent dye molecular material; Figure 5 Volt-ampere characteristic curve of the Control cell of a perovskite solar cell prepared by undoped organic fluorescent dye molecular material. Detailed implementation manners

[0019] The following describes exemplary embodiments of the present invention with reference to the accompanying drawings. Various details of the embodiments of the present invention are included to facilitate understanding, and they should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, descriptions of well-known functions and structures are omitted below for clarity and conciseness.

[0020] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0021] As Figure 1 - Figure 4 shown, the technical solution of the present invention: A preparation method of a wide-bandgap perovskite solar cell, comprising the following steps: S1: Preparation of the ITO layer: Obtain a heterojunction crystalline silicon cell, and deposit ITO on the heterojunction crystalline silicon cell using magnetron sputtering technology. The sputtering power is 50 - 300 W, the sputtering time is 3 - 30 min, and the thickness of the ITO coating is set to 50 - 150 nm; S2: O2-plasma treatment: Perform O2-plasma treatment for 5 - 15 min to remove residual organic substances on the surface of the transparent conductive substrate and improve the work function; S3: Preparation of the hole transport layer: Place the processed sample into a glove box under a nitrogen atmosphere, and prepare a hole transport layer on the sample. The material of the hole transport layer is selected as [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid, with a concentration of 0.1-5 mg ml -1 , and the solvent is ethanol. Use the spin coating method to evenly coat the solution, with the rotation speed set at 1000-10000 rpm. After spin coating, transfer it to a hot plate at 80-150 °C for annealing for 5-30 min; S4: Preparation of the perovskite light-absorbing thin film layer: Add the perovskite precursor material to the corresponding solvent in a preset ratio and stir and oscillate to obtain a perovskite precursor solution. Incorporate the organic fluorescent material NPBI2 into the prepared perovskite precursor solution, with a concentration of 0.5-5 mg mL -1 ; Use a spin coater to spin coat an appropriate amount of the mixed solution onto the hole transport layer. The process of dropping the antisolvent chlorobenzene during spin coating includes: The first step: Select a rotation speed range of 500-2000 rpm, and the rate of increase of the rotation speed is 100-2000 rpm s -1 , and the time is 10 s; The second step: Select a rotation speed range of 2000-10000 rpm, and the rate of increase of the rotation speed is 1000-10000 rpm s -1 , and the time is 30 s; Drop 100-3000 μL of chlorobenzene as the antisolvent at the 25th second. After spin coating, place the obtained perovskite light-absorbing layer on a hot plate for annealing. The annealing temperature is 80 °C to 150 °C, and the annealing time is 5-90 min to obtain the perovskite light-absorbing thin film layer; S5: Coating the PEAI post-treatment salt: The selected ammonium salts include at least one of phenyltrimethylammonium salt, benzylammonium salt, tetrabutylammonium salt, and octylammonium salt. The selected solvents include at least one of isopropanol, acetonitrile, chlorobenzene, and chloroform, and are mixed in a preset ratio. The solution concentration is set at 0.5-10 mg ml -1 ; Use a spin coater to spin coat an appropriate amount of the mixed solution onto the perovskite light-absorbing thin film layer. The process includes: Select a spin coating rotation speed range of 1000-10000 rpm, a spin coating time of 10-90 s. After spin coating, place the passivated perovskite light-absorbing layer on a hot plate for annealing. The annealing temperature is 80-150 °C, and the annealing time is 5-30 min; S6: Preparation of the thermally evaporated C60 electron transport layer: Transfer the passivated perovskite light-absorbing thin film layer to an organic material evaporation chamber, and evaporate the electron transport layer C60 with a thickness of 10-50 nm and an evaporation rate of 0.1-5 Å s -1 ; S7: Preparation of SnO2 electron transport layer by atomic layer deposition method: Using tetraethyltin as the precursor, deposit for 20 - 300 cycles with a thickness of 10 - 60 nm. The specific process is as follows: Precurser introduction: Introduce tetraethyltin into the reaction chamber to adsorb it on the substrate surface; Purge: Use an inert gas to purge the reaction chamber to remove the unreacted precursor; Reaction gas introduction: Introduce oxygen to react with the tetraethyltin adsorbed on the substrate to form SnO2; Purge again: Use an inert gas to purge again to remove the reaction by-products and unreacted reaction gases; S8: Depositing ITO transparent conductive electrode by magnetron sputtering technology: Put the sample into the vacuum chamber of the magnetron sputtering coater, adjust the vacuum degree to 10 -4 ~10 -5 Pa. The magnetron sputtering coater deposits an ITO transparent conductive electrode with a thickness of 80 - 150 nm on the SnO2 electron transport layer. Set the sputtering power to 50 - 300 W. The working gas pressure and gas ratio are mainly argon with a flow rate of 20 - 40 sccm, and the addition amount of O2 is 0.5 - 2% to control the oxygen vacancies in the film; The substrate temperature ≤ 80 °C, and the target-substrate distance is 6 - 10 cm, taking into account both uniformity and particle energy attenuation; Control the deposition rate to 5 - 15 nm / min, with a thickness of 80 - 150 nm, corresponding to a sputtering time of 10 - 30 min, and the total gas pressure is 0.3 - 1.0 Pa; S9: Preparation of metal grid lines: Evaporate silver metal grid lines in the metal evaporation chamber with a thickness of 60 - 200 nm and an evaporation rate of 0.1 - 10 Å s -1 , and adopt stepped rate regulation; S10: Evaporating MgF2 antireflection layer: Use a thermal evaporation coating device. Put the sample into the vacuum chamber and adjust the vacuum degree to 10 -4 ~10 -5 Pa. Evaporate the MgF2 antireflection layer with an evaporation rate of 0.1 - 1 Å s -1 , and the thickness of the MgF2 antireflection layer is 60 - 200 nm.

[0022] The preferred embodiments disclosed in the present invention are as Figures 1-4 shown: A preparation method of a wide-bandgap perovskite solar cell, comprising the following steps: S1: Preparation of ITO layer: Obtain a heterojunction crystalline silicon cell, and deposit ITO on the heterojunction crystalline silicon cell using magnetron sputtering technology. The sputtering power is 50 - 300 W, the sputtering time is 3 - 30 min, and the ITO coating thickness is set to 50 - 150 nm. In this embodiment, obtain a sputtering target, select a sputtering power of 150 W, a sputtering time of 8 min, and the obtained ITO thickness is 100 nm ± 10 nm.

[0023] S2: Perform O2 - plasma treatment: Perform O2 - plasma treatment with a treatment time of 5 - 15 min to remove residual organic substances on the surface of the transparent conductive substrate and improve the work function. In this embodiment, the selected treatment time for this step is 4 min.

[0024] S3: Preparation of the hole - transporting layer: Place the treated sample in a glove box with a nitrogen atmosphere, and prepare a hole - transporting layer on the sample. The material of the hole - transporting layer is selected as [4 - (3,6 - dimethyl - 9H - carbazol - 9 - yl) butyl] phosphoric acid, with a concentration of 0.1 - 5 mg / ml -1 , the solvent is ethanol, and the solution is uniformly coated using the spin - coating method, with the rotation speed set to 1000 - 10000 rpm. After spin - coating, it is transferred to a hot plate at 80 - 150 °C for annealing for 5 - 30 min; In this embodiment, the selected concentration is 0.5 mg / ml -1 , the solvent is ethanol, and the solution is uniformly coated using the spin - coating method, with the rotation speed set to 3000 rpm. After spin - coating, it is transferred to a hot plate at 100 °C for annealing for 5 min.

[0025] S4: Preparation of the perovskite light - absorbing thin - film layer: Add the perovskite precursor material to the corresponding solvent in a preset ratio and stir and oscillate to obtain a perovskite precursor solution. The perovskite precursor material is selected from at least two of lead iodide, lead chloride, lead bromide, formamidinium iodide, formamidinium chloride, formamidinium bromide, methylammonium iodide, methylammonium chloride, methylammonium bromide, cesium iodide, cesium chloride, cesium bromide, rubidium iodide, rubidium chloride, rubidium bromide, and mixed in a preset ratio; the solvent is selected from at least two of dimethylformamide, dimethyl sulfoxide, N - methylpyrrolidone, and mixed in a preset ratio; in this embodiment, the selected perovskite precursor material is rubidium iodide (RbI), cesium iodide (CsI), methylammonium bromide (MABr), formamidinium iodide (FAI), and lead iodide (PbI2) with a molar ratio of 0.05:0.05:0.05:0.85:1, and the total molar concentration of the perovskite components is 1.4 mol / L -1; The solvent is selected from at least two of dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N-methylpyrrolidone (NMP) and mixed in a preset ratio. The volume ratios are DMF:DMSO = 3:1 to 9:1, DMF:NMP = 4:1 to 9:1, and DMF:DMSO:NMP = 8:1:1. A perovskite precursor solution is obtained, and the organic fluorescent material NPBI2 is incorporated into the prepared perovskite precursor solution at a concentration of 0.5 - 5 mg mL -1 , and in this embodiment, a concentration of 1 mg ml -1 is selected; The molecular formula of NPBI2 is as Figure 3 shown; An appropriate amount of the mixed solution is spin-coated onto the hole transport layer using a spin coater. The process of dropping the antisolvent chlorobenzene during spin coating includes: The first step: The rotation speed range is selected from 500 - 2000 rpm, and the increasing rate of the rotation speed is 100 - 2000 rpm s -1 , the time is 10 s, and in this embodiment, a rotation speed of 2000 rpm and an increasing rate of the rotation speed of 1000 rpm s -1 are selected; The second step: The rotation speed range is selected from 2000 - 10000 rpm, and the increasing rate of the rotation speed is 1000 - 10000 rpm s -1 , the time is 30 s, and in this embodiment, a rotation speed of 5000 rpm and an increasing rate of the rotation speed of 5000 rpm s -1 are selected; 150 µL of chlorobenzene is dropped as an antisolvent at the 25th second. After spin coating, the obtained perovskite light-absorbing layer is placed on a hot stage for annealing. The annealing temperature is 80°C to 150°C, and the annealing time is 5 - 90 min. In this embodiment, an annealing temperature of 100°C and an annealing time of 10 min are selected to obtain a perovskite light-absorbing thin film layer.

[0026] S5: Coating the post-treatment salt of PEAI: The selected ammonium salts include at least one of phenyltrimethylammonium salt, benzylammonium salt, tetrabutylammonium salt, and octylammonium salt. The selected solvents include at least one of isopropyl alcohol, acetonitrile, chlorobenzene, and chloroform, and are mixed in a preset ratio. The solution concentration is set to 0.5 - 10 mg ml -1 ; In this embodiment, the selected ammonium salt is phenyltrimethylammonium salt, the selected solvent and volume ratio are chlorobenzene:isopropyl alcohol = 1:2, and the solution concentration is 1 mg ml -1; Use a spin coater to spin coat an appropriate amount of the mixed solution onto the perovskite light-absorbing thin film layer. The process includes: selecting the spin coating speed range from 1000 - 10000 rpm, the spin coating time is 10 - 90 s. After spin coating, place the passivated perovskite light-absorbing layer on a hot plate for annealing, the annealing temperature is 80 - 150 °C, and the annealing time is 5 - 30 min; In this embodiment, the selected spin coating process is 4000 rpm, the time is 30 s, and then anneal at 100 °C for 5 min.

[0027] S6: Preparation of the thermally evaporated C60 electron transport layer: Transfer the passivated perovskite light-absorbing thin film layer to an organic material evaporation chamber, and evaporate the electron transport layer C60 with a deposition rate of 0.1 nm / s -1 , with a thickness of 10 - 50 nm and an evaporation rate of 0.1 - 5 Å / s -1 , In this embodiment, 35 nm is selected for deposition.

[0028] S7: Preparation of the SnO2 electron transport layer by atomic layer deposition: Use tetraethyltin as the precursor, deposit 20 - 300 cycles, with a thickness of 10 - 60 nm. The specific process is as follows: Precursor introduction: Introduce tetraethyltin into the reaction chamber to adsorb it on the substrate surface; Purge: Use an inert gas (such as argon) to purge the reaction chamber to remove unreacted precursors; Reaction gas introduction: Introduce oxygen to react with the tetraethyltin adsorbed on the substrate to form SnO2; Purge again: Use an inert gas to purge again to remove reaction by-products and unreacted reaction gases; In this embodiment, 250 cycles are selected for deposition, with a thickness of 20 nm.

[0029] S8: Magnetron sputtering technology to deposit the ITO transparent conductive electrode: Place the sample in the vacuum chamber of a magnetron sputtering coater, adjust the vacuum degree to 10 -4 ~10 -5 Pa. The magnetron sputtering coater deposits an 80 - 150 nm thick ITO transparent conductive electrode on the SnO2 electron transport layer. The sputtering power is set to 50 - 300 W. The working gas pressure and gas ratio are mainly argon, with a flow rate of 20 - 40 sccm, and the O2 addition amount is 0.5 - 2% to control the oxygen vacancies in the thin film; The substrate temperature ≤ 80 °C, the target-substrate distance is 6 - 10 cm, taking into account both uniformity and particle energy attenuation; The deposition rate is controlled at 5 - 15 nm / min, and 80 - 150 nm The thickness corresponds to a sputtering time of 10 - 30 min; The total gas pressure is 0.3 - 1.0 Pa. Too low a gas pressure causes damage to high-energy particles, and too high a gas pressure reduces the film density; In this embodiment, an ITO transparent conductive electrode is deposited by magnetron sputtering technology. The sputtering target is ITO, the sputtering power is 150 W, and the sputtering time is 10 min. The obtained ITO thickness is approximately 120 nm ± 10 nm.

[0030] S9: Preparation of metal grid lines: Silver metal grid lines are evaporated in a metal evaporation chamber with a thickness of 60 - 200 nm and an evaporation rate of 0.1 - 10 Å s -1 , and a stepped rate control is adopted, specifically: When the evaporated metal thickness is 0 - 10 nm, the rate is 0.1 Å s -1 ; when the thickness is 10 - 20 nm, the rate is 0.2 Å s -1 ; when the thickness is 20 - 30 nm, the rate is 0.3 Å s -1 ; when the thickness is 30 - 40 nm, the rate is 0.3 Å s -1 ; when the thickness is 40 - 50 nm, the rate is 0.4 Å s -1 ; when the thickness is 50 - 60 nm, the rate is 0.5 Å s -1 ; when the thickness is 60 - 70 nm, the rate is 0.6 Å s -1 ; when the thickness is 70 - 200 nm, the rate is 1 - 10 Å s -1 .

[0031] S10: Evaporation of MgF2 antireflection layer: Using a thermal evaporation coating equipment, the sample is placed in a vacuum chamber, and the vacuum degree is adjusted to 10 -4 ~10 -5 Pa, and the evaporation rate is 0.1 - 1 Å s -1 , and an MgF2 antireflection layer is evaporated with a thickness of 60 - 200 nm; in this embodiment, 150 nm MgF2 is selected for evaporation as the antireflection layer, and the preparation method of the wide-bandgap perovskite solar cell is completed.

[0032] A wide-bandgap perovskite solar cell is fabricated using the preparation method of the wide-bandgap perovskite solar cell.

[0033] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims, and all of them fall within the protection scope of the present invention.

Claims

1. A method for preparing a wide bandgap perovskite solar cell, characterized in that: The steps include: S1: ITO layer preparation: Obtain a heterogeneous crystalline silicon cell, and use a magnetron sputtering technique to plate ITO on the heterogeneous crystalline silicon cell, with a sputtering power of 50-300 W, a sputtering time of 3-30 min, and an ITO coating thickness of 50-150 nm; S2: O2-plasma treatment: Performing O2-plasma treatment for 5-15 minutes to remove organic matter remaining on the surface of the transparent conductive substrate and improve the work function; S3: Preparation of hole transport layer: The treated sample was placed in a glove box with a nitrogen atmosphere, and a hole transport layer was prepared on the sample. The material of the hole transport layer was [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid with a concentration of 0.1-5 mg mL -1 , the solvent is ethanol, and the solution is evenly coated by spin coating, the rotation speed is set to 1000-10000rpm, and after the spin coating is completed, it is transferred to a hot stage at 80-150℃ for annealing for 5-30min; S4: Preparation of perovskite light-absorbing thin film layer: The perovskite precursor material is added to the corresponding solvent in a preset ratio and stirred and shaken to obtain a perovskite precursor solution. The organic fluorescent material NPBI2 is then added to the prepared perovskite precursor solution at a concentration of 0.5-5 mg mL -1 ; A proper amount of the mixed solution is spin-coated onto the hole transport layer using a coating machine, and the process of adding chlorobenzene anti-solvent dropwise during the spin coating comprises: Step 1: Select the speed range of 500-2000rpm, and the speed increase rate is 100-2000rpm s -1 , time is 10s; Step 2: Select the speed range of 2000-10000 rpm, and the speed increase rate is 1000-10000rpm s -1 , the time is 30s; at the 25th second, 100-3000μL chlorobenzene is added as an anti-solvent, and after the spin coating is completed, the obtained perovskite light-absorbing layer is placed on a hot stage for annealing, the annealing temperature is 80°C to 150°C, and the annealing time is 5-90 min to obtain a perovskite light-absorbing film layer; S5: PEAI post-treatment salt: The selected ammonium salt includes at least one of phenyltrimethylammonium salt, benzylammonium salt, tetrabutylammonium salt, and octylammonium salt, and the selected solvent includes at least one of isopropanol, acetonitrile, chlorobenzene, and chloroform, which are mixed in a preset ratio, and the solution concentration is set to 0.5-10 mg ml -1 ; Use a coating machine to spin coat an appropriate amount of the mixed solution onto the perovskite light-absorbing film layer, the process comprising: selecting a spin coating speed range of 1000-10000 rpm, a spin coating time of 10-90 s, and after the spin coating is completed, placing the passivated perovskite light-absorbing layer on a hot stage for annealing, the annealing temperature is 80-150° C., and the annealing time is 5-30 min; S6: Preparation of thermally evaporated C60 electron transport layer: The passivated perovskite light-absorbing film layer is transferred to an organic material evaporation chamber, and an electron transport layer C60 is evaporated to a thickness of 10-50 nm and an evaporation rate of 0.1-5 Å s -1 ; S7: Preparation of SnO2 electron transport layer by atomic layer deposition: Tetraethyltin is used as a precursor, and the deposition is performed for 20-300 cycles with a thickness of 10-60 nm. The specific process is as follows: Precursor introduction: tetraethyltin is introduced into the reaction chamber to be adsorbed on the substrate surface; Purge: an inert gas is used to purge the reaction chamber to remove unreacted precursor; Reaction gas introduction: oxygen is introduced to react with tetraethyltin adsorbed on the substrate to form SnO2; Re-purge: an inert gas is used to purge again to remove reaction byproducts and unreacted reaction gas; S8: ITO transparent conductive electrode plated by magnetron sputtering technology: Place the sample in the vacuum chamber of the magnetron sputtering coating machine and adjust the vacuum degree to 10 -4 ~10 -5 Pa, magnetron sputtering coater deposits 80-150nm thick ITO transparent conductive electrode on SnO2 electron transport layer, sputtering power is set to 50-300W, working pressure and gas ratio are mainly argon, flow rate is 20-40 sccm, O2 addition amount is 0.5-2%, in order to control the oxygen vacancies of thin film; substrate temperature ≤80℃, target substrate distance is 6-10 cm, taking into account uniformity and particle energy attenuation; deposition rate is controlled to 5-15 nm / min, thickness is 80-150nm, corresponding to sputtering time 10-30min, total gas pressure is 0.3-1.0 Pa; S9: Preparation of metal grid lines: Silver metal grid lines are deposited in the metal deposition chamber with a thickness of 60-200 nm and a deposition rate of 0.1-10 Å s -1 , using step-by-step rate control; S10: Evaporation of MgF2 anti-reflection layer: Use thermal evaporation coating equipment to place the sample into a vacuum chamber and adjust the vacuum degree to 10 -4 ~10 -5 Pa, evaporation rate is 0.1-1 Å s -1 , evaporate MgF2 anti-reflection layer with a thickness of 60-200 nm.

2. The method for preparing a wide bandgap perovskite solar cell according to claim 1, characterized in that: In S1, the ITO sputtering power is 150 W, the sputtering time is 8 min, and the obtained ITO thickness is 100 nm ± 10 nm.

3. The method for preparing a wide bandgap perovskite solar cell according to claim 1, characterized in that: In S3, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid was used at a concentration of 0.5 mg ml -1 , the solvent was ethanol, the spin coating process was 3000 rpm, the time was 30 s, and then transferred to a 100 ° C hot stage for annealing for 5 min.

4. The method for preparing a wide bandgap perovskite solar cell according to claim 1, characterized in that: In S4, the perovskite precursor material is selected from at least two of lead iodide, lead chloride, lead bromide, iodoformamidine, formamidine chloride, formamidine bromide, methylamine iodine, methylamine chloride, methylamine bromide, cesium iodide, cesium chloride, cesium bromide, rubidium iodide, rubidium chloride, and rubidium bromide, and mixed in a preset ratio; the solvent is selected from at least two of dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone, and mixed in a preset ratio to obtain a perovskite precursor solution, and NPBI2 is added to the prepared perovskite precursor solution at a concentration of 1 mg ml -1 ; A proper amount of the mixed solution is spin-coated onto the hole transport layer using a coating machine, and the process of adding the anti-solvent during the spin coating includes: The first step: the rotation speed is 2000 rpm and the time is 10s; the second step: the rotation speed is 5000 rpm and the time is 30s; at the 25th second, 150µL of chlorobenzene is added as an anti-solvent. After the spin coating is completed, the obtained perovskite light-absorbing layer is placed on a hot stage for annealing at a temperature of 100°C and a time of 10 min.

5. The method for preparing a wide bandgap perovskite solar cell according to claim 1, characterized in that: In S5, PEAI post-treatment salt was applied, the selected ammonium salt was phenyltrimethylammonium salt, the selected solvent and volume ratio were chlorobenzene:isopropanol 1:2, and the solution concentration was 1 mg ml -1 The spin coating process was 4000 rpm for 30 s, followed by annealing at 100 °C for 5 min.

6. The method for preparing a wide bandgap perovskite solar cell according to claim 1, characterized in that: In S7, tetraethyltin was used as a precursor and the SnO2 electron transport layer was prepared by a deposition method with 250 cycles and a thickness of 20 nm.

7. The method for preparing a wide bandgap perovskite solar cell according to claim 1, characterized in that: In S8, magnetron sputtering technology was used to plate ITO transparent conductive electrode. The sputtering target was ITO, the sputtering power was 150 W, the sputtering time was 10 min, and the obtained ITO thickness was approximately 120 nm ± 10 nm.

8. The method for preparing a wide bandgap perovskite solar cell according to claim 1, characterized in that: In S9, silver metal grid lines were evaporated with a thickness of 60-200 nm, and the rate was controlled by a stepwise method: when the thickness of the evaporated metal was 0-10 nm, the rate was 0.1 Å s -1 ; When the thickness is 10-20 nm, the rate is 0.2 Å s -1 ; When the thickness is 20-30 nm, the rate is 0.3Å s -1 ; When the thickness is 30-40 nm, the rate is 0.3 Å s -1 ; When the thickness is 40-50 nm, the rate is 0.4 Å s -1 ; When the thickness is 50-60 nm, the rate is 0.5 Å s -1 ; When the thickness is 60-70 nm, the rate is 0.6 Å s -1 ; for thicknesses of 70-200 nm, the rate is 1-10 Å s -1 .

9. The method for preparing a wide bandgap perovskite solar cell according to claim 1, characterized in that: In S10, 150 nm MgF2 is evaporated as an anti-reflection layer.

10. A wide bandgap perovskite solar cell, characterized in that: It is prepared using the method for preparing a wide bandgap perovskite solar cell according to any one of claims 1 to 9.

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