A method for manufacturing a flexible two-dimensional thin-film solar cell

Abstract

This invention relates to a method for fabricating a flexible two-dimensional thin-film solar cell, comprising two main steps: fabrication of the flexible two-dimensional thin-film solar cell substrate and fabrication of the flexible two-dimensional thin-film solar cell structure. The method utilizes laser etching to create a flexible two-dimensional thin-film solar cell electrode array, and employs electro-jet printing to fabricate the electron transport layer and hole transport layer of the flexible two-dimensional thin-film solar cell, forming a two-dimensional flexible thin-film solar cell with higher light transmittance. Compared with existing thin-film solar cell fabrication methods, this invention has the advantages of simple manufacturing process, convenient operation, lower cost, and no reliance on cleanroom equipment, which is beneficial for the research, development, application, and promotion of flexible two-dimensional thin-film solar cells.

Description

Technical Field

[0001] This invention relates to a method for fabricating solar cells, and more particularly to a method for fabricating flexible two-dimensional thin-film solar cells based on laser etching and electro-jet printing. Background Technology

[0002] Flexible thin-film solar cells possess advantages such as high integration, low cost, large-area automated production, light weight, and excellent bending performance. They are widely used in building-integrated photovoltaics, portable wearable photovoltaic devices, and solar-powered vehicles, demonstrating significant development potential and a promising market outlook. Currently, thin-film solar cells use very few raw materials, requiring only a few micrometers of material. The film can be directly deposited onto the substrate, giving it a significant advantage over traditional rigid-based solar cells. Given the continued shortage of raw materials in the international market, it has become a new direction for the development of the international photovoltaic market.

[0003] Currently, a crucial indicator for thin-film solar cells is sufficient flexibility to adhere to the surfaces of wearable devices or large curved building materials. To ensure flexibility, processes such as optical exposure, deep reactive ion etching, and argon plasma sputtering are typically employed to fabricate a three-dimensional sandwich structure containing electrode layers, hole transport layers, and electron transport layers. This three-dimensional structure easily leads to decreased light transmittance in the solar cell, and the manufacturing process is complex and costly. Furthermore, while these processes can produce high-precision flexible thin-film solar cells, they rely on cleanrooms and specialized equipment, limiting their widespread application in research. Therefore, designing and developing a low-cost, cleanroom-free, simple, and easy-to-operate fabrication process for high-transmittance two-dimensional thin-film solar cells is an urgent problem to be solved. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for preparing a flexible two-dimensional thin-film solar cell, comprising the following steps:

[0005] Step 1: Fabrication of Flexible Two-Dimensional Thin-Film Solar Cell Substrate

[0006] (1) Prepare PAA (Poly amic acid) solution and multi-walled carbon nanotubes at a weight ratio of 95-100:1, stir and mix thoroughly, and then perform defoaming treatment; spin-coat the defoamed PAA mixture onto the surface of a polished silicon wafer with a spin-coating thickness of 400-500 micrometers.

[0007] (2) The PAA spin-coated on the silicon wafer surface is heated and cured to form a polyimide film; after soaking in deionized water for 10-15 minutes, the polyimide film is peeled off from the silicon wafer and dried, and the dried polyimide film is fixed onto the glass as a polyimide substrate.

[0008] (3) PEO (Polyethylene oxide) powder is added to silver nitrate solution and mixed by magnetic stirring to prepare a PEO / silver nitrate mixture with a concentration of 0.1-0.15 mg / mL; the mixture is spin-coated onto a polyimide substrate with a thickness of 200-250 μm; the spin-coated film is dried to form a polyimide substrate for the PEO / silver nitrate film;

[0009] (4) A carbon dioxide laser ablation is used to etch a graphene electrode array on the substrate surface obtained in step (3); the graphene electrode array includes two groups, each group including several parallel graphene electrodes, the graphene electrodes in the two groups of graphene electrode arrays are arranged alternately, and the ends of the graphene electrodes in each group are connected; each graphene electrode has a width of 0.8-1 mm and a thickness of 235-295 micrometers, and the spacing between the graphene electrodes is 0.4-0.5 mm;

[0010] Step 2: Fabrication of Flexible Two-Dimensional Thin-Film Solar Cell Structure

[0011] (1) The side of the flexible two-dimensional thin film solar cell substrate prepared in step one with PEO / silver nitrate film is treated with oxygen plasma.

[0012] (2) Pour titanium dioxide into isopropanol solution to prepare an electron transport layer solution of 80-90 mg / mL. After stirring thoroughly, pour it into an electro-jet printing nozzle. Align the nozzle with the graphene electrode of the flexible two-dimensional thin-film solar cell substrate. Then, use an electro-jet printer to print an electron transport layer on the graphene electrode of one of the graphene electrode arrays. The width of the electron transport layer is 1-1.2 mm and the thickness is 200-300 nm. Place the flexible two-dimensional thin-film solar cell substrate in an oven for annealing.

[0013] (3) Lithium bis(trifluoromethanesulfonyl)imide was poured into an acetonitrile solution to prepare a 5-6 mg / mL lithium bis(trifluoromethanesulfonyl)imide solution; Spiro-OMeTAD was poured into a chlorobenzene solution to prepare a 72-73 mg / mL Spiro-OMeTAD solution; the lithium bis(trifluoromethanesulfonyl)imide solution, tributyl phosphate, and Spiro-OMeTAD solution were prepared at a volume ratio of (18-20):(29-30):(1-2), and after magnetic stirring, a hole transport layer solution was formed; the hole transport layer solution was poured into an electro-jet printing nozzle, and after aligning the nozzle with the graphene electrode of the flexible two-dimensional thin-film solar cell substrate, a hole transport layer was printed on the graphene electrode of another set of graphene electrode arrays using an electro-jet printer. The hole transport layer had a width of 1-1.2 mm and a thickness of 200-300 nm.

[0014] (4) DMF (Dimethylformamide) and DMSO (Dimethyl sulfoxide) are prepared at a volume ratio of 4-5:1 to form a DMF / DMSO solution; PbI2 (LeadI iodide) and MAI (methylamine) are prepared at a weight ratio of 2-3:1 to form a PbI2 / MAI powder; PbI2-MAI powder is poured into the DMF-DMSO solution to prepare a perovskite solution with a concentration of 640-650 mg / mL; the perovskite solution is spin-coated onto a flexible two-dimensional thin-film solar cell substrate; after spin-coating, the flexible two-dimensional thin-film solar cell substrate is placed in an oven for annealing to form a perovskite thin film with a thickness of 400-500 nm;

[0015] (5) Prepare a mixture of PDMS (Polydimethylsiloxane) prepolymer and curing agent at a volume ratio of 9-10:1 and stir thoroughly; add toluene to the PDMS mixture at a volume ratio of 4-5:1 and stir thoroughly. Spin coat the mixture onto the flexible two-dimensional thin-film solar cell substrate obtained in step (4), and dry it to form a PDMS film with a thickness of 20-30 micrometers.

[0016] This ultimately forms a flexible two-dimensional thin-film solar cell.

[0017] As a preferred option, in step one (1), the defoaming process parameters are: vacuum degree 100-150 Pa, vacuuming time 35-45 minutes; the spin coating process parameters are: spin coating speed 3000-3500 rpm, spin coating time 20-30 seconds.

[0018] Preferably, in step one (2), the PAA heating and curing sequence and parameters are as follows:

[0019] 1) Heating temperature: 90-95 degrees Celsius; heating time: 20-25 minutes;

[0020] 2) Heating temperature: 160-165 degrees Celsius; heating time: 30-35 minutes;

[0021] 3) Heating temperature: 210-215 degrees Celsius; heating time: 40-45 minutes;

[0022] 4) Heating temperature: 250-255 degrees Celsius; heating time: 20-25 minutes;

[0023] 5) Heating temperature 290-295 degrees Celsius, heating time 20-25 minutes.

[0024] The drying process parameters for polyimide film are: drying temperature 200-250 degrees Celsius, drying time 10-15 minutes.

[0025] Preferably, in step one (3), the concentration of silver nitrate solution is 0.1 mol / L; the magnetic stirring parameters are: stirring speed 20-30 rpm, stirring time 0.5-1 hour; the spin coating process parameters are: spin coating speed 2000-2500 rpm, spin coating time 15-20 seconds; and the drying process parameters for PEO / silver nitrate film are: drying temperature 200-250 degrees Celsius, drying time 20-25 minutes.

[0026] As a preferred option, in step one (4), the graphene laser ablation parameters are: ablation power of 8-10 watts and etching speed of 5-6 cm / s.

[0027] As a preferred option, in step two (1), the oxygen plasma treatment parameters are: power of 10-15 watts, treatment time of 20-30 seconds, and distance from the spray gun to the substrate of 1-2 centimeters.

[0028] As a preferred option, in step two (2), the electro-jet printing parameters are: printing distance 2-3 mm, ink flow rate 0.1-0.15 ml / h, printing speed 2-2.5 cm / s, excitation voltage 2500-3000 volts; the annealing process parameters are: drying temperature 200-220 degrees Celsius, drying time 30-35 minutes.

[0029] As a preferred option, in step two (3), the magnetic stirring parameters are: rotation speed 40-50 rpm, stirring time 6-6.5 hours; the electro-jet printing parameters are: printing distance 2-3 mm, ink flow rate 0.1-0.15 ml / h, printing speed 2-2.5 cm / s, and excitation voltage 2000-2500 volts.

[0030] Preferably, in step two (4), the spin coating process parameters are: spin coating speed 3000-3500 rpm.

[0031] Spin coating time is 15-20 seconds; annealing process parameters are: annealing temperature 100-120 degrees Celsius, drying time 20-25 minutes.

[0032] Preferably, in step two (5), the spin coating process parameters are: spin coating speed 3000-3500 rpm.

[0033] Spin coating time is 40-45 seconds; drying process parameters are: drying temperature 200-250 degrees Celsius, drying time 15-20 minutes.

[0034] The beneficial effects of this invention are:

[0035] This invention utilizes laser ablation to form graphene electrodes and employs electro-jet printing to manufacture electron transport layers and hole transport layers. Compared with existing flexible thin-film solar cell manufacturing methods, this invention has the advantages of simple manufacturing process, convenient operation, and lower cost. By precisely controlling various parameters, electrodes, hole transport layers, and electron transport layers that meet the requirements can be prepared, forming a two-dimensional flexible thin-film solar cell with higher light transmittance. It does not rely on cleanroom equipment and provides a reference for the preparation of two-dimensional flexible thin-film solar cells, which is conducive to the application and promotion of thin-film solar cells. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of the flexible two-dimensional thin-film solar cell of the present invention;

[0037] Figure 2 This is a schematic diagram of the graphene electrode array structure of the present invention;

[0038] Figure 3 This is a diagram of the graphene electrode array structure of the present invention;

[0039] Figure 4 This is a scanning electron microscope image of the graphene electrode of the present invention;

[0040] Figure 5 This is a schematic diagram of the electron transport layer structure printed by electro-jet printing according to the present invention;

[0041] Figure 6 This is a schematic diagram of the hole transport layer structure printed by the electro-jet printer of the present invention;

[0042] Figure 7 This is a schematic diagram of the current-voltage test data of the flexible two-dimensional thin-film solar cell of the present invention.

[0043] 1. Polyimide film 2. PEO / silver nitrate film 3. Graphene electrode array 4. Electron transport layer 5. Hole transport layer 6. Perovskite film 7. PDMS film. Detailed Implementation

[0044] See Figure 1-7 As shown:

[0045] The present invention provides a method for fabricating a flexible two-dimensional thin-film solar cell, comprising the following steps:

[0046] Step 1: Fabrication of Flexible Two-Dimensional Thin-Film Solar Cell Substrate

[0047] (1) Prepare PAA solution and multi-walled carbon nanotubes at a weight ratio of 100:1, pour into a glass beaker, stir and mix thoroughly, and then perform defoaming treatment. The defoaming process parameters are: vacuum degree 100-150 Pa, vacuuming time 35-45 minutes; spin-coat the defoamed PAA mixture onto the surface of a single-sided polished silicon wafer at a spin-coating speed of 3000-3500 rpm, a spin-coating time of 20-30 seconds, and a spin-coating thickness of 400-500 micrometers; adding carbon nanotubes to PAA helps to reduce the resistance of graphene formed by subsequent laser ablation and improve conductivity.

[0048] (2) The PAA spin-coated on the silicon wafer surface is heated and cured to form a polyimide film 1; the heating and curing sequence and parameters are as follows:

[0049] 1) Heating temperature: 90-95 degrees Celsius; heating time: 20-25 minutes;

[0050] 2) Heating temperature: 160-165 degrees Celsius; heating time: 30-35 minutes;

[0051] 3) Heating temperature: 210-215 degrees Celsius; heating time: 40-45 minutes;

[0052] 4) Heating temperature: 250-255 degrees Celsius; heating time: 20-25 minutes;

[0053] 5) Heating temperature 290-295 degrees Celsius, heating time 20-25 minutes.

[0054] After the cured polyimide film is soaked in deionized water for 10-15 minutes, it is peeled off from the silicon wafer and dried at a temperature of 200-250 degrees Celsius for 10-15 minutes. After drying, the dried polyimide film is fixed to the glass with tape to serve as a polyimide substrate.

[0055] (3) PEO powder is added to a silver nitrate solution with a concentration of 0.1 mol / L and mixed with magnetic stirring to prepare a PEO / silver nitrate mixture with a concentration of 0.1 mg / mL. The stirring speed is 20-30 rpm and the stirring time is 0.5-1 hour. The mixture is spin-coated onto a polyimide substrate at a speed of 2000-2500 rpm for 15-20 seconds, and the spin-coating thickness is 200-250 μm. The spin-coated film is dried at a temperature of 200-250 degrees Celsius for 20-25 minutes to form a polyimide substrate with PEO / silver nitrate film 2. Since PEO is a conductive polymer and silver nitrate will form nano-silver particles during subsequent laser etching, the graphene after laser etching will have a lower resistivity, and the thin-film solar cell will have better electrical performance.

[0056] (4) A carbon dioxide laser ablation is used to etch a graphene electrode array 3 on the substrate surface obtained in step (3). The ablation power is 8-10 watts and the etching speed is 5-6 cm / s. The graphene electrode array 3 includes two groups, each group including several parallel graphene electrodes. The graphene electrodes in the two groups of graphene electrode arrays are arranged alternately and the tail ends of the graphene electrodes in each group are connected. The width of each graphene electrode is 0.8-1 mm and the thickness is 235-295 micrometers. The spacing between the graphene electrodes is 0.4-0.5 mm.

[0057] Step 2: Fabrication of Flexible Two-Dimensional Thin-Film Solar Cell Structure

[0058] (1) The side of the flexible two-dimensional thin film solar cell substrate with PEO / silver nitrate film prepared in step one is treated with oxygen plasma. The oxygen plasma treatment parameters are: power of 10-15 watts, treatment time of 20-30 seconds, and distance from the spray gun to the substrate of 1-2 cm. Oxygen plasma treatment is beneficial to improve the bonding strength between the flexible two-dimensional thin film solar cell structure and the substrate.

[0059] (2) Pour titanium dioxide into isopropanol solution to prepare an electron transport layer solution of 80 mg / mL. After stirring thoroughly, pour it into the electro-jet printing nozzle. Align the nozzle with the graphene electrode of the flexible two-dimensional thin-film solar cell substrate. Electro-jet print the electron transport layer 4 on the graphene electrode of one of the graphene electrode arrays 3. The width of the electron transport layer 4 is 1-1.2 mm and the thickness is 200-300 nm. The printing distance of the electro-jet printing is 2-3 mm, the ink flow rate is 0.1-0.15 mL / h, the printing speed is 2-2.5 cm / s, and the excitation voltage is 2500-3000 V. Place the printed flexible two-dimensional thin-film solar cell substrate in an oven for annealing. The annealing process parameters are: drying temperature 200-220 degrees Celsius and drying time 30-35 minutes.

[0060] (3) Lithium bis(trifluoromethanesulfonyl)imide was added to acetonitrile solution to prepare a 5 mg / mL lithium bis(trifluoromethanesulfonyl)imide solution; Spiro-OMeTAD was added to chlorobenzene solution to prepare a 72 mg / mL Spiro-OMeTAD solution; the lithium bis(trifluoromethanesulfonyl)imide solution, tributyl phosphate, and Spiro-OMeTAD solution were prepared at a volume ratio of 18:29:1 and magnetically stirred to form a hole transport layer solution; the magnetic stirring parameters were: rotation speed 40-50 rpm, stirring time 6-6.5 hours;

[0061] The hole transport layer solution is poured into the electro-jet printing nozzle. After aligning the nozzle with the graphene electrode of the flexible two-dimensional thin-film solar cell substrate, the hole transport layer 5 is printed on the graphene electrode of another set of graphene electrode array 3 using electro-jet printing. The hole transport layer 5 has a width of 1-1.2 mm and a thickness of 200-300 nanometers. The electro-jet printing distance is 2-3 mm, the ink flow rate is 0.1-0.15 ml / h, the printing speed is 2-2.5 cm / s, and the excitation voltage is 2000-2500 volts.

[0062] (4) DMF and DMSO are prepared in a volume ratio of 4:1 to form a DMF / DMSO solution; PbI2 and MAI are prepared in a weight ratio of 3:1 to form PbI2 / MAI powder; PbI2-MAI powder is poured into the DMF-DMSO solution to prepare a perovskite solution of 640 mg / mL; the perovskite solution is spin-coated onto a flexible two-dimensional thin-film solar cell substrate at a spin-coating speed of 3000-3500 rpm and a spin-coating time of 15-20 seconds; after spin-coating, the flexible two-dimensional thin-film solar cell substrate is placed in an oven for annealing to form a perovskite film 6 with a thickness of 400-500 nm; the annealing process parameters are: annealing temperature of 100-120 degrees Celsius and drying time of 20-25 minutes.

[0063] (5) Prepare a mixture of PDMS prepolymer and curing agent at a volume ratio of 10:1, pour it into a petri dish and stir thoroughly; add toluene to the PDMS mixture at a volume ratio of 5:1, stir thoroughly, and spin coat it onto the flexible two-dimensional thin film solar cell substrate obtained in step (4). The spin coating speed is 3000-3500 rpm and the spin coating time is 40-45 seconds; after drying, a PDMS film 7 is formed with a thickness of 20-30 micrometers; the drying temperature is 200-250 degrees Celsius and the drying time is 15-20 minutes.

[0064] This ultimately forms a flexible two-dimensional thin-film solar cell.

[0065] The flexible two-dimensional thin-film solar cell prepared in this embodiment was used for testing. The current-voltage test data structure is as follows: Figure 7 As shown.

Claims

1. A method of fabricating a flexible two-dimensional thin-film solar cell, characterized by: Includes the following steps: Step 1: Fabrication of Flexible Two-Dimensional Thin-Film Solar Cell Substrate (1) Prepare PAA solution and multi-walled carbon nanotubes at a weight ratio of 95-100:1, stir and mix thoroughly, and then perform defoaming treatment; spin-coat the defoamed PAA mixture onto the surface of a polished silicon wafer with a spin-coating thickness of 400-500 micrometers. (2) Heat and cure the PAA spin-coated on the silicon wafer to form a polyimide film; after soaking in deionized water for 10-15 minutes, peel the polyimide film off the silicon wafer and dry it, and fix the dried polyimide film onto the glass as a polyimide substrate. (3) PEO powder is added to silver nitrate solution and mixed by magnetic stirring to prepare a PEO / silver nitrate mixture with a concentration of 0.1-0.15 mg / mL; the mixture is spin-coated onto a polyimide substrate with a thickness of 200-250 μm; the spin-coated film is dried to form a polyimide substrate of PEO / silver nitrate film; (4) A carbon dioxide laser ablation is used to etch a graphene electrode array on the substrate surface obtained in step (3); the graphene electrode array includes two groups, each group including several parallel graphene electrodes, the graphene electrodes in the two groups of graphene electrode arrays are arranged alternately, and the ends of the graphene electrodes in each group are connected; each graphene electrode has a width of 0.8-1 mm and a thickness of 235-295 micrometers, and the spacing between the graphene electrodes is 0.4-0.5 mm; Step 2: Fabrication of Flexible Two-Dimensional Thin-Film Solar Cell Structure (1) The side of the flexible two-dimensional thin film solar cell substrate with PEO / silver nitrate film prepared in step one is treated with oxygen plasma. (2) Pour titanium dioxide into isopropanol solution to prepare an electron transport layer solution of 80-90 mg / mL. After stirring thoroughly, pour it into an electro-jet printing nozzle. Align the nozzle with the graphene electrode of the flexible two-dimensional thin-film solar cell substrate. Then, use an electro-jet printer to print an electron transport layer on the graphene electrode of one of the graphene electrode arrays. The width of the electron transport layer is 1-1.2 mm and the thickness is 200-300 nm. Place the flexible two-dimensional thin-film solar cell substrate in an oven for annealing. (3) Lithium bis(trifluoromethanesulfonyl)imide was poured into acetonitrile solution to prepare a 5-6 mg / mL lithium bis(trifluoromethanesulfonyl)imide solution; Spiro-OMeTAD was poured into chlorobenzene solution to prepare a 72-73 mg / mL Spiro-OMeTAD solution; the lithium bis(trifluoromethanesulfonyl)imide solution, tributyl phosphate, and Spiro-OMeTAD solution were prepared at a volume ratio of (18-20):(29-30):(1-2), and after magnetic stirring, a hole transport layer solution was formed. The hole transport layer solution is poured into the electro-jet printing nozzle. After aligning the nozzle with the graphene electrode of the flexible two-dimensional thin-film solar cell substrate, the hole transport layer is printed on the graphene electrode of another set of graphene electrode arrays using electro-jet printing. The hole transport layer has a width of 1-1.2 mm and a thickness of 200-300 nanometers. (4) Prepare a DMF / DMSO solution by mixing DMF and DMSO at a volume ratio of 4-5:1; prepare a PbI2 / MAI powder by mixing PbI2 and MAI at a weight ratio of 2-3:1; pour the PbI2-MAI powder into the DMF-DMSO solution to prepare a perovskite solution with a concentration of 640-650 mg / mL. The perovskite solution was spin-coated onto a flexible two-dimensional thin-film solar cell substrate. After spin-coating, the flexible two-dimensional thin-film solar cell substrate was placed in an oven for annealing to form a perovskite thin film with a thickness of 400-500 nanometers. (5) Prepare a mixture of PDMS prepolymer and curing agent at a volume ratio of 9-10:1 and stir thoroughly; add toluene to the PDMS mixture at a volume ratio of 4-5:1 and stir thoroughly. Spin coat the mixture onto the flexible two-dimensional thin film solar cell substrate obtained in step (4), and dry it to form a PDMS film with a thickness of 20-30 micrometers. This ultimately forms a flexible two-dimensional thin-film solar cell.

2. The method for preparing a flexible two-dimensional thin-film solar cell according to claim 1, characterized in that: In step one (1), the defoaming process parameters are: vacuum degree 100-150 Pa, vacuuming time 35-45 minutes; the spin coating process parameters are: spin coating speed 3000-3500 rpm, spin coating time 20-30 seconds.

3. The method for preparing a flexible two-dimensional thin-film solar cell according to claim 1, characterized in that: In step one (2), the PAA heating curing sequence and parameters are as follows: 1) Heating temperature: 90-95 degrees Celsius; heating time: 20-25 minutes; 2) Heating temperature: 160-165 degrees Celsius; heating time: 30-35 minutes; 3) Heating temperature: 210-215 degrees Celsius; heating time: 40-45 minutes; 4) Heating temperature: 250-255 degrees Celsius; heating time: 20-25 minutes; 5) Heating temperature 290-295 degrees Celsius, heating time 20-25 minutes; The drying process parameters for polyimide film are: drying temperature 200-250 degrees Celsius, drying time 10-15 minutes.

4. The method for preparing a flexible two-dimensional thin-film solar cell according to claim 1, characterized in that: In step one (3), the concentration of silver nitrate solution is 0.1 mol / L; the magnetic stirring parameters are: stirring speed 20-30 rpm, stirring time 0.5-1 hour; the spin coating process parameters are: spin coating speed 2000-2500 rpm, spin coating time 15-20 seconds; the drying process parameters of PEO / silver nitrate film are: drying temperature 200-250 degrees Celsius, drying time 20-25 minutes.

5. The method for preparing a flexible two-dimensional thin-film solar cell according to claim 1, characterized in that: In step one (4), the graphene laser ablation parameters are: ablation power of 8-10 watts and etching speed of 5-6 cm / s.

6. The method for preparing a flexible two-dimensional thin-film solar cell according to claim 1, characterized in that: In step two (1), the oxygen plasma treatment parameters are: power of 10-15 watts, treatment time of 20-30 seconds, and distance from the spray gun to the substrate of 1-2 cm.

7. The method for preparing a flexible two-dimensional thin-film solar cell according to claim 1, characterized in that: In step two (2), the electro-jet printing parameters are: printing distance 2-3 mm, ink flow rate 0.1-0.15 ml / h, printing speed 2-2.5 cm / s, excitation voltage 2500-3000 volts; the annealing process parameters are: drying temperature 200-220 degrees Celsius, drying time 30-35 minutes.

8. The method for preparing a flexible two-dimensional thin-film solar cell according to claim 1, characterized in that: In step two (3), the magnetic stirring parameters are: rotation speed 40-50 rpm, stirring time 6-6.5 hours; the electro-jet printing parameters are: printing distance 2-3 mm, ink flow rate 0.1-0.15 ml / h, printing speed 2-2.5 cm / s, excitation voltage 2000-2500 volts.

9. The method for preparing a flexible two-dimensional thin-film solar cell according to claim 1, characterized in that: In step two (4), the spin coating process parameters are: spin coating speed 3000-3500 rpm, spin coating time 15-20 seconds; the annealing process parameters are: annealing temperature 100-120 degrees Celsius, drying time 20-25 minutes.

10. The method for preparing a flexible two-dimensional thin-film solar cell according to claim 1, characterized in that: In step two (5), the spin coating process parameters are: spin coating speed 3000-3500 rpm, spin coating time 40-45 seconds; The drying process parameters are: drying temperature 200-250 degrees Celsius, drying time 15-20 minutes.

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