Carbon-based perovskite solar cell and preparation method thereof

Abstract

The application provides a carbon-based perovskite solar cell and a preparation method thereof. The method comprises the step of preparing a laminated structure, the laminated structure comprising a transparent conductive substrate and an electron transport layer, a mesoporous layer, a perovskite active layer and a carbon electrode layer arranged on the surface of the transparent conductive substrate in sequence, the carbon electrode layer comprising a main body layer part and an electrode part, the main body layer part being arranged on the surface of the perovskite active layer away from the transparent conductive substrate, the electrode part being arranged on the transparent conductive substrate and being in contact with the electron transport layer, the mesoporous layer and the perovskite active layer, and the surface of the electrode part and the main body layer part away from the transparent conductive substrate being flush. After the step of preparing the laminated structure, the preparation method comprises: applying pressure perpendicular to the laminated structure to the laminated structure while performing annealing treatment, to obtain the carbon-based perovskite solar cell. By using the above method provided in the application, the stability of the carbon-based perovskite solar cell can be significantly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a carbon-based perovskite solar cell and a preparation method thereof. Background Art

[0002] Photovoltaic technology is increasingly playing a role in the new energy system. Currently, perovskite solar cells are a hot topic in the field. Since their introduction, they have achieved a certified photoelectric conversion efficiency of 26%, promising market entry. However, expensive hole transport materials and metal electrodes, as well as the complex and energy-intensive vacuum evaporation process, significantly increase the cost of perovskite solar cells.

[0003] Carbon materials are inexpensive, abundant in reserves, chemically stable, and easy to modify on the surface. Furthermore, as electrode materials, they also possess a certain hole transport capability. Therefore, carbon-based perovskite solar cells without a hole transport layer have received widespread attention in recent years. Carbon-based perovskite solar cells without a hole transport layer are generally composed of transparent conductive glass, an electron transport layer, a perovskite light-absorbing layer, and a carbon electrode, where the carbon electrode serves as both a counter electrode and a transporter of hole carriers. Compared to traditional structural devices, carbon-based perovskite solar cells without a hole transport layer lack a hole transport layer, and the carbon electrode prepared by the doctor blade method has poor contact with the perovskite layer, resulting in a short transmission distance for hole carriers at the interface between the perovskite layer and the carbon electrode, severe carrier recombination, and a low photoelectric conversion efficiency of the device.

[0004] Chemical strategies such as additives, passivation processes, and interlayer insertion are often employed to improve the contact between the carbon electrode and the perovskite layer, enhance hole carrier transport between the two layers, and optimize device performance. However, the carbon electrode preparation process requires a certain amount of heating, which can cause adverse reactions between the additive and the perovskite layer or render the additive ineffective upon heating, negatively impacting device performance.

[0005] Therefore, it is urgent to develop a preparation method for carbon-based perovskite solar cells to improve the contact between the carbon electrode and the perovskite active layer, optimize the transmission of carriers at the interface, achieve efficient carrier separation, and improve the photoelectric conversion efficiency of carbon-based perovskite solar cells without hole transport layers. Summary of the Invention

[0006] The main purpose of the present invention is to provide a carbon-based perovskite solar cell and a preparation method thereof, so as to solve the problem in the prior art that the interface contact between the carbon electrode layer and the perovskite active layer in the carbon-based perovskite solar cell is poor, resulting in obvious hysteresis effect and low photoelectric conversion efficiency.

[0007] In order to achieve the above-mentioned objectives, on the one hand, the present invention provides a method for preparing a carbon-based perovskite solar cell, comprising the step of preparing a laminated structure, the laminated structure comprising a transparent conductive substrate and an electron transport layer, a mesoporous layer, a perovskite active layer and a carbon electrode layer sequentially stacked on its surface. After the step of preparing the laminated structure, the preparation method comprises: applying pressure perpendicular to the laminated structure to the laminated structure and performing annealing treatment simultaneously to obtain a carbon-based perovskite solar cell.

[0008] Furthermore, a Hoffman clamp is used to apply pressure to the laminate structure; and / or, the annealing treatment includes a heating stage, a holding stage and a cooling stage; preferably, the pressure is 10 to 100 Pa, the heating rate in the heating stage is 6 to 10°C / min, the temperature in the holding stage is 40 to 65°C, and the holding time is 2 to 12 minutes.

[0009] Furthermore, the carbon electrode layer is prepared by a doctor blade coating method; preferably, the thickness of the carbon electrode layer is 5 to 20 μm.

[0010] Furthermore, the perovskite active layer is prepared by a two-step anti-solvent spin coating method; preferably, the thickness of the perovskite active layer is 400 to 560 nm; and / or, the material of the perovskite active layer is Cs 1-x FA x PbI3, where FA is formamidine, 0.77≤x≤0.82.

[0011] Furthermore, when the material of the perovskite active layer is Cs 0.21 FA 0.79 When the material of the perovskite active layer is Cs, the pressure is 55-60 Pa, the heating rate in the heating stage is 8-10 ° C / min, the temperature in the holding stage is 58-62 ° C, and the holding time is 8-12 min. 0.23 FA 0.77 When the material of the perovskite active layer is Cs, the pressure is 20-55 Pa, the heating rate in the heating stage is 6-9 ° C / min, the temperature in the holding stage is 40-50 ° C, and the holding time is 4-8 min. 0.19 FA 0.81 When PbI3 is used, the pressure is 65-100 Pa, the heating rate in the heating stage is 7-9°C / min, the temperature in the insulation stage is 46-60°C, and the insulation time is 2-5 min.

[0012] Further, when the thickness of the carbon electrode layer is 5-10 μm, the pressure is 50-75 Pa, the temperature increasing rate in the temperature increasing stage is 6-7 ℃ / min, the temperature in the temperature maintaining stage is 54-62 ℃, and the temperature maintaining time is 8-12 min; when the thickness of the carbon electrode layer is 13-20 μm, the pressure is 30-58 Pa, the temperature increasing rate in the temperature increasing stage is 6-9 ℃ / min, the temperature in the temperature maintaining stage is 47-60 ℃, and the temperature maintaining time is 7-11 min.

[0013] Further, the electron transport layer is prepared by chemical bath deposition, spin coating or magnetron sputtering; preferably, the thickness of the electron transport layer is 20-60 nm; and / or, the material of the electron transport layer is selected from one or more of the group consisting of titanium dioxide, tin dioxide and zinc oxide.

[0014] Further, the mesoporous layer is prepared by spin coating; preferably, the thickness of the mesoporous layer is 50-94 nm; and / or, the material of the mesoporous layer is selected from one or more of the group consisting of titanium dioxide, aluminum oxide and zirconium oxide.

[0015] Further, the transparent conductive substrate is selected from one or more of the group consisting of FTO conductive glass, ITO conductive glass and IZO conductive glass.

[0016] In order to achieve the above-mentioned purpose, another aspect of the present application further provides a carbon-based perovskite solar cell prepared by the above-mentioned method for preparing a carbon-based perovskite solar cell.

[0017] By applying the technical solution of the present application, the perovskite active layer can be recrystallized through in-situ pressure annealing of the stacked structure, so as to reduce the defect state density of the perovskite active layer, effectively reduce the stress between the perovskite active layer itself and the carbon electrode layer in the carbon-based perovskite solar cell, improve the bonding force between the perovskite active layer and the carbon electrode layer, improve the interface contact therebetween, thereby improving the extraction and transmission of hole carriers between the perovskite active layer and the carbon electrode layer, improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell, and reducing the hysteresis effect. Moreover, the improvement of the interface contact between the perovskite active layer and the carbon electrode layer in the carbon-based perovskite solar cell can effectively inhibit the immersion of external moisture, thereby improving the stability of the carbon-based perovskite solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application. In the drawings:

[0019] Figure 1A schematic structural diagram of a carbon-based perovskite solar cell in a preferred embodiment of the present application is shown;

[0020] Figure 2 The current-voltage curves (JV curves, forward scan) of the carbon-based perovskite solar cells prepared in Example 1 and Comparative Example 1 of the present application are shown;

[0021] Figure 3 The current-voltage curves (JV curves, reverse scan) of the carbon-based perovskite solar cells prepared in Example 1 and Comparative Example 1 of the present application are shown.

[0022] The above drawings include the following reference numerals:

[0023] 10. Transparent conductive substrate; 20. Electron transport layer; 30. Mesoporous layer; 40. Perovskite active layer; 50. Carbon electrode layer. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0025] As described in the background art, the existing carbon-based perovskite solar cells have poor interface contact between the carbon electrode and the perovskite active layer, resulting in a significant hysteresis effect and low photoelectric conversion efficiency. In order to solve the above technical problems, the present application provides a method for preparing a carbon-based perovskite solar cell, comprising the steps of preparing a laminated structure, the laminated structure comprising a transparent conductive substrate 10 and an electron transport layer 20, a mesoporous layer 30, a perovskite active layer 40 and a carbon electrode layer 50 sequentially stacked on its surface, the carbon electrode layer 50 comprising a main layer portion and an electrode portion, the main layer portion being arranged on a side surface of the perovskite active layer 40 away from the transparent conductive substrate 10, the electrode portion being arranged on the transparent conductive substrate 10 and in contact with the electron transport layer 20, the mesoporous layer 30 and the perovskite active layer 40, and the electrode portion and the main layer portion having a side surface away from the transparent conductive substrate 10 being flush, after the step of preparing the laminated structure, the preparation method comprises: applying a pressure perpendicular to the laminated structure to the laminated structure while performing an annealing treatment to obtain a carbon-based perovskite solar cell.

[0026] Currently, common post-processing methods for perovskite solar cells often involve chemical methods that introduce additives. However, given that the carbon electrodes in carbon-based perovskite solar cells require high-temperature heating, the added chemical reagents may thermally decompose or react with the perovskite during heating, leading to reduced performance of the perovskite solar cell.

[0027] This application is passed by Figure 1The stacked structure shown is subjected to in-situ pressure annealing, which can cause the perovskite active layer 40 to undergo secondary crystallization, thereby reducing the defect state density of the perovskite active layer 40, effectively reducing the stress within the perovskite active layer 40 itself and between it and the carbon electrode layer 50 in the carbon-based perovskite solar cell, and improving the bonding force between the perovskite active layer 40 and the carbon electrode layer 50, thereby improving the interface contact between the two, and improving the extraction and transmission of hole carriers between the perovskite active layer 40 and the carbon electrode layer 50, thereby improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell and reducing the hysteresis effect. Moreover, the improvement of the interface contact between the perovskite active layer 40 and the carbon electrode layer 50 in the carbon-based perovskite solar cell can effectively inhibit the infiltration of external moisture, thereby improving the stability of the carbon-based perovskite solar cell.

[0028] In a preferred embodiment, a Hoffman clamp is used to apply pressure to the laminated structure. Compared to other pressurizing devices, using a Hoffman clamp to apply pressure to the laminated structure facilitates more precise control of the pressure, thereby facilitating easier regulation of the physical contact between the perovskite active layer 40 and the carbon electrode layer 50, thereby improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell while reducing the hysteresis effect. Furthermore, the Hoffman clamp is simple and economical to operate, eliminating the need for expensive, high-end processing equipment, thereby reducing production costs.

[0029] It should be noted that the material of the Hoffman clip used in the present application can be a metal alloy, and there is no special requirement for the size, as long as it can accommodate the above-mentioned laminated structure provided in the present application.

[0030] In a preferred embodiment, the annealing process includes a heating stage, a heat preservation stage and a cooling stage.

[0031] In a preferred embodiment, the pressure is 10-100 Pa, the heating rate in the heating stage is 6-10°C / min, the temperature in the holding stage is 40-65°C, and the holding time is 2-12 minutes. The applied pressure, the heating rate in the heating stage, the temperature in the holding stage, and the holding time include but are not limited to the above ranges. Limiting them to the above ranges is beneficial to improving the bonding force between the perovskite active layer 40 and the carbon electrode layer 50, and is beneficial to improving the extraction and transmission of hole carriers between the perovskite active layer 40 and the carbon electrode layer 50, thereby improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell and reducing the hysteresis effect.

[0032] In a preferred embodiment, the carbon electrode layer 50 is prepared by a doctor blade coating method. Compared with other methods, the use of a doctor blade coating method to prepare the carbon electrode layer 50 is beneficial for improving the uniformity of the properties of the carbon electrode layer 50, thereby improving the electrochemical performance of the carbon-based perovskite solar cell and reducing the preparation cost.

[0033] In a preferred embodiment, the preparation process of the carbon electrode layer 50 includes: preparing a carbon-containing material slurry; using a doctor blade to coat the carbon-containing material slurry, and after a curing process, obtaining the carbon electrode layer 50, which includes a main layer part and an electrode part.

[0034] In a preferred embodiment, the carbon-containing material slurry includes 2-5 parts of carbon material, 2-5 parts of resin binder, 3-8 parts of solvent, and 1-3 parts of filler by weight. Preferably, the carbon material includes but is not limited to one or more of graphite, carbon black, and graphene; the resin binder includes but is not limited to one or more of ethyl cellulose, polyvinylpyrrolidone, and sodium carboxymethyl starch; and the filler includes but is not limited to one or more of nano-alumina, nano-zirconia, and nano-silica.

[0035] In a preferred embodiment, the average particle size of the filler is 3-10 nm. The average particle size of the filler includes but is not limited to the above range, and limiting it within the above range is beneficial to improve the strength of the carbon electrode layer 50, while also being beneficial to exert the electron blocking effect of the filler.

[0036] In order to improve the coverage, uniformity, and conductivity of the carbon electrode, preferably, the coating amount of the carbon-containing material slurry is 1-10 mg / cm 2 .

[0037] In a preferred embodiment, the thickness of the carbon electrode layer 50 is 5-20 μm. The thickness of the carbon electrode layer 50 includes but is not limited to the above range, and limiting it within the above range is beneficial to improve the processability of the stacked structure, is beneficial to inhibit the stacked structure from being damaged when subjected to an applied pressure, and is thus beneficial to improve the photoelectric conversion efficiency of the carbon-based perovskite solar cell.

[0038] In a preferred embodiment, the perovskite active layer 40 is prepared by a two-step anti-solvent spin coating method. Compared to other methods, using the two-step anti-solvent spin coating method to prepare the perovskite active layer 40 is beneficial to form a perovskite active layer 40 with more uniform composition in each part, while also being beneficial to improve the stability of the perovskite active layer 40, and the process is easy to operate.

[0039] In a preferred embodiment, the preparation process of the perovskite active layer 40 includes: preparing a perovskite precursor solution; spin-coating the perovskite precursor solution on the surface of the mesoporous layer 30, dripping an anti-solvent, and annealing to obtain a laminated structure containing the perovskite active layer 40, wherein the spin-coating process includes low-speed spin-coating and high-speed spin-coating, wherein the low-speed spin-coating speed is 460 to 1000 rpm and the time is 8 to 10 seconds, and the high-speed spin-coating speed is 4500 to 5200 rpm and the time is 17 to 22 seconds. Preferably, the anti-solvent includes, but is not limited to, one or more of the group consisting of isopropyl ether, diethyl ether, ethyl acetate, and diethyl carbonate.

[0040] In a preferred embodiment, the thickness of the perovskite active layer 40 is 400 to 560 nm. The thickness of the perovskite active layer 40 includes, but is not limited to, the aforementioned range. Limiting the thickness of the perovskite active layer 40 to the aforementioned range is beneficial for improving photon absorption efficiency, accelerating carrier separation and transmission, and thus improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell.

[0041] In a preferred embodiment, the material of the perovskite active layer 40 is Cs 1-x FA x PbI3, where FA is formamidine, and 0.77≤x≤0.82. The material of the perovskite active layer 40 includes, but is not limited to, the above range. Limiting it to the above range is beneficial for achieving a more suitable band gap, more excellent theoretical photovoltaic properties, and a longer carrier lifetime, thereby facilitating improved photoelectric conversion efficiency of the carbon-based perovskite solar cell.

[0042] In a preferred embodiment, when the material of the perovskite active layer 40 is Cs 0.21 FA 0.79 When the material of the perovskite active layer 40 is Cs, the pressure is 55-60 Pa, the heating rate in the heating stage is 8-10 ° C / min, the temperature in the holding stage is 58-62 ° C, and the holding time is 8-12 min. 0.23 FA 0.77 When the material of the perovskite active layer 40 is Cs, the pressure is 20-55 Pa, the heating rate in the heating stage is 6-9 ° C / min, the temperature in the holding stage is 40-50 ° C, and the holding time is 4-8 min. 0.19 FA 0.81When PbI3 is used, the pressure is 65-100 Pa, the heating rate in the heating stage is 7-9°C / min, the temperature in the holding stage is 46-60°C, and the holding time is 2-5 minutes. For different types of perovskite active layers 40, adopting the above-mentioned preferred ranges of pressure, heating rate in the heating stage, temperature and holding time in the holding stage is beneficial to further improve the bonding force between the perovskite active layer 40 and the carbon electrode layer 50, and to further improve the extraction and transmission of hole carriers between the perovskite active layer 40 and the carbon electrode layer 50, thereby further improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell and further reducing the hysteresis effect.

[0043] In a preferred embodiment, when the thickness of the carbon electrode layer 50 is 5 to 10 μm, the pressure is 50 to 75 Pa, the heating rate in the heating stage is 6 to 7°C / min, the temperature in the holding stage is 54 to 62°C, and the holding time is 8 to 12 minutes; when the thickness of the carbon electrode layer 50 is 13 to 20 μm, the pressure is 30 to 58 Pa, the heating rate in the heating stage is 6 to 9°C / min, the temperature in the holding stage is 47 to 60°C, and the holding time is 7 to 11 minutes. For carbon electrode layers 50 of different thicknesses, adopting the above preferred ranges of pressure, temperature in the holding stage, and holding time is beneficial to further improve the bonding force between the perovskite active layer 40 and the carbon electrode layer 50, and to further improve the extraction and transmission of hole carriers between the perovskite active layer 40 and the carbon electrode layer 50, thereby further improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell and further reducing the hysteresis effect.

[0044] In a preferred embodiment, the electron transport layer 20 is prepared by chemical bath deposition, spin coating, or magnetron sputtering. Compared to other methods, preparing the electron transport layer 20 using the above methods improves its interfacial contact with the transparent conductive substrate 10, thereby accelerating the extraction and transport of electrons and improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell.

[0045] In order to further improve the interface contact between the electron transport layer 20 and the transparent conductive substrate 10, thereby facilitating improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell, preferably, the thickness of the electron transport layer 20 is 20 to 60 nm; the material of the electron transport layer 20 includes but is not limited to one or more of the group consisting of titanium dioxide, tin dioxide and zinc oxide.

[0046] In a preferred embodiment, the mesoporous layer 30 is prepared by spin coating. Compared with other methods, the above method for preparing the mesoporous layer 30 is more conducive to the orderly growth of the subsequent perovskite active layer 40 and improves the film quality, thereby improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell.

[0047] In order to further improve the carrier transmission efficiency and further improve the photoelectric conversion efficiency of carbon-based perovskite solar cells, preferably, the thickness of the mesoporous layer 30 is 50 to 94 nm; the material of the mesoporous layer 30 includes but is not limited to one or more of the group consisting of titanium dioxide, aluminum oxide and zirconium oxide.

[0048] In a preferred embodiment, the transparent conductive substrate 10 includes, but is not limited to, one or more of the group consisting of FTO conductive glass, ITO conductive glass, and IZO conductive glass. These transparent conductive substrates 10 have high light transmittance and good conductivity, and are suitable for preparing carbon-based perovskite solar cells.

[0049] In a second aspect, the present application further provides a carbon-based perovskite solar cell, which is produced by the above-mentioned method for producing a carbon-based perovskite solar cell provided in the present application. The carbon-based perovskite solar cell produced in the present application has the advantages of high photoelectric conversion efficiency and good stability.

[0050] The present application is further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0051] Example 1

[0052] A method for preparing a carbon-based perovskite solar cell, comprising:

[0053] (1) Prepare FTO conductive glass with a square resistance of 15Ω / sq, and use a laser to etch a rectangular insulating area on the conductive surface of the FTO conductive glass to prepare for the subsequent scraping of the carbon electrode layer 50; the remaining functional layers are all carried out on the unetched area of ​​the FTO conductive glass; ultrasonically clean the etched FTO conductive glass with deionized water, isopropyl alcohol, and ethanol for 25 minutes, and then blow dry it with an air gun for later use;

[0054] (2) Preparation of titanium dioxide electron transport layer 20: Prepare a titanium tetrachloride aqueous solution with a concentration of 180 mmol / L; affix polyimide tape to the other side of the insulating area of ​​the FTO conductive glass, immerse the FTO conductive glass with the tape in the titanium tetrachloride aqueous solution, heat it at 80°C for 60 minutes, and then rinse it with deionized water until the surface of the FTO conductive glass is obviously unchanged; then heat it on a hot plate at 120°C for 10 minutes and cool it to room temperature;

[0055] (3) Preparation of the titanium dioxide mesoporous layer 30: Commercial titanium dioxide (Dyesol, 30NR-D) and ethanol were mixed at a weight ratio of 1:5.9 and stirred for 16 h to obtain a titanium dioxide slurry; the titanium dioxide slurry was spin-coated on the surface of the titanium dioxide electron transport layer 20 at a speed of 4000 rpm for 20 s; the slurry was then transferred to a muffle furnace, kept at 520°C for 30 min, and cooled;

[0056] (4)Cs 0.21 FA 0.79 Preparation of the PbI3 perovskite active layer 40: 51 mg of CsI, 137 mg of FAI (formamidine iodide), and 462 mg of PbI2 were weighed separately, 145 mL of DMSO and 489 μL of DMF were pipetted, mixed and shaken for 1 hour, and then filtered through a 0.22 μm polytetrafluoroethylene filter to obtain a perovskite precursor solution; the perovskite precursor solution was used as a spin coating solution, and a two-step antisolvent spin coating method was adopted, first spinning at a low speed of 1000 rpm for 10 seconds, then spinning at a high speed of 4500 rpm for 20 seconds. At the 10th second of high-speed rotation, 150 μL of isopropyl ether was added dropwise, and the mixture was transferred to a glove box and annealed at 165°C for 26 minutes;

[0057] (5) Preparation of the carbon electrode layer 50: Prepare a carbon-containing material slurry, wherein, by weight, the carbon-containing material slurry comprises 1.2 parts of graphite, 1.4 parts of carbon black, 0.4 parts of graphene, 1.6 parts of ethyl cellulose, 0.4 parts of sodium carboxymethyl starch, 2.5 parts of terpineol, 0.3 parts of chlorobenzene, 0.2 parts of anisole and 1 part of nano-alumina (average particle size of 2 to 8 nm), and the solid content of the carbon-containing material slurry is 66.7%; in the Cs 0.21 FA 0.79 The surface of the PbI3 perovskite active layer 40 is coated with the above-mentioned carbon-containing material slurry. The coating amount of the carbon-containing material slurry is 6 mg / cm 2 After curing at 120℃ for 20min, the following laminated structure was obtained: FTO conductive glass / titanium dioxide electron transport layer / titanium dioxide mesoporous layer / Cs 0.21 FA 0.79 PbI3 perovskite active layer / carbon electrode layer 50, such as Figure 1 As shown, the carbon electrode layer 50 includes a main layer portion and an electrode portion. The main layer portion is disposed on a surface of the perovskite active layer 40 away from the transparent conductive substrate 10. The electrode portion is disposed on the transparent conductive substrate 10 and is disposed in contact with the electron transport layer 20, the mesoporous layer 30, and the perovskite active layer 40. The electrode portion and the main layer portion are flush with each other on a surface away from the transparent conductive substrate 10.

[0058] (6) applying a pressure of 60 Pa to the structure obtained in step (5) using a Hoffman clamp; transferring the Hoffman clamp containing the laminated structure to a muffle furnace, heating the mixture to 60° C. at a rate of 8° C. / min, keeping the temperature for 10 min, and then naturally cooling the mixture to room temperature in air to obtain a carbon-based perovskite solar cell.

[0059] In the carbon-based perovskite solar cell prepared in this embodiment, the thickness of the titanium dioxide electron transport layer 20 is 26 nm, the thickness of the titanium dioxide mesoporous layer 30 is 65 nm, and the Cs 0.21 FA 0.79 The thickness of the PbI 3 perovskite active layer 40 is 462 nm, and the thickness of the carbon electrode layer 50 is 7 μm.

[0060] Example 2

[0061] The difference from Example 1 is that in step (6), the applied pressure is 10 Pa, the heating rate in the heating stage is 6°C / min, the temperature in the holding stage is 65°C, and the holding time is 2 min. The remaining steps are the same as in Example 1.

[0062] Example 3

[0063] The difference from Example 1 is that in step (6), the applied pressure is 100 Pa, the heating rate in the heating stage is 10°C / min, the temperature in the holding stage is 40°C, and the holding time is 12 min. The remaining steps are the same as in Example 1.

[0064] Example 4

[0065] The difference from Example 1 is that in step (6), the applied pressure is 150 Pa, the heating rate in the heating stage is 15°C / min, the temperature in the holding stage is 70°C, and the holding time is 15 min. The remaining steps are the same as in Example 1.

[0066] Example 5

[0067] The difference from Example 1 is that the coating amount of the carbon-containing material slurry is changed so that the thickness of the carbon electrode layer 50 is 5 μm. In step (6), the applied pressure is 75 Pa, the heating rate in the heating stage is 6°C / min, and the temperature in the holding stage is 54°C for 8 minutes. The remaining steps are the same as in Example 1.

[0068] Example 6

[0069] The difference from Example 1 is that the coating amount of the carbon-containing material slurry is changed so that the thickness of the carbon electrode layer 50 is 20 μm. In step (6), the applied pressure is 30 Pa, the heating rate in the heating stage is 9°C / min, and the temperature in the holding stage is 60°C for 11 minutes. The remaining steps are the same as in Example 1.

[0070] Example 7

[0071] The difference from Example 1 is that in step (6), the applied pressure is 55 Pa, the heating rate in the heating stage is 10°C / min, the temperature in the holding stage is 58°C, and the holding time is 12 min. The remaining steps are the same as in Example 1.

[0072] Example 8

[0073] The difference from Example 1 is that in step (6), the applied pressure is 60 Pa, the heating rate in the heating stage is 8°C / min, the temperature in the holding stage is 62°C, and the holding time is 8 minutes. The remaining steps are the same as in Example 1.

[0074] Example 9

[0075] The difference from Example 1 is that in step (6), the perovskite precursor solution is prepared so that the material of the prepared perovskite active layer 40 is Cs 0.23 FA 0.77 PbI3; the applied pressure was 20Pa, the heating rate in the heating stage was 9°C / min, the temperature in the holding stage was 40°C, and the time was 8min; the remaining steps were the same as in Example 1.

[0076] Example 10

[0077] The difference from Example 1 is that in step (6), the perovskite precursor solution is prepared so that the material of the prepared perovskite active layer 40 is Cs 0.23 FA 0.77 PbI3; the applied pressure was 55Pa, the heating rate in the heating stage was 6°C / min, the temperature in the holding stage was 50°C, and the time was 4min; the remaining steps were the same as in Example 1.

[0078] Example 11

[0079] The difference from Example 1 is that in step (6), the perovskite precursor solution is prepared so that the material of the prepared perovskite active layer 40 is Cs 0.19 FA 0.81 PbI3; the applied pressure was 65Pa, the heating rate in the heating stage was 9°C / min, the temperature in the holding stage was 46°C, and the time was 5min; the remaining steps were the same as in Example 1.

[0080] Example 12

[0081] The difference from Example 1 is that in step (6), the perovskite precursor solution is prepared so that the material of the prepared perovskite active layer 40 is Cs 0.19 FA 0.81PbI3; the applied pressure was 100Pa, the heating rate in the heating stage was 7°C / min, the temperature in the holding stage was 60°C, and the time was 2min; the remaining steps were the same as in Example 1.

[0082] Comparative Example 1

[0083] The difference from Example 1 is that the treatment process of step (6) is not performed. The remaining steps are the same as those in Example 1.

[0084] The light source is Newport Oriel Sol 3A from the United States, at 100mW·cm -2 The short-circuit current density J of the carbon-based perovskite solar cells prepared in all the above embodiments and comparative examples of this application was tested under light conditions. sc , open circuit voltage V oc , fill factor FF and photoelectric conversion efficiency PCE, among which the test area of ​​carbon-based perovskite solar cells is 0.1cm 2 , the test results are shown in Table 1. Figure 2 and Figure 3 The forward scan and reverse scan JV curves of the carbon-based perovskite solar cells prepared in Example 1 and Comparative Example 1 of the present application are respectively shown.

[0085] Table 1

[0086]

[0087] The residual stress of the perovskite active layer 40 in all the above-mentioned embodiments and comparative examples of the present application was calculated using the Hall-Williams equation, and the calculation results are shown in Table 2. The defect state density of the perovskite active layer 40 and the hole mobility of the carbon-based perovskite solar cell in all the above-mentioned embodiments and comparative examples of the present application were calculated based on the Mott-Gurney law, and the calculation results are shown in Table 2.

[0088] Table 2

[0089]

[0090]

[0091] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0092] Comparing Example 1 and Comparative Example 1, it can be seen that the present invention Figure 1The stacked structure shown is subjected to in-situ pressure annealing, which can cause the perovskite active layer 40 to undergo secondary crystallization, thereby reducing the defect state density of the perovskite active layer 40, effectively reducing the stress within the perovskite active layer 40 itself and between it and the carbon electrode layer 50, and improving the bonding force between the perovskite active layer 40 and the carbon electrode layer 50, thereby improving the interface contact between the two, and improving the extraction and transmission of hole carriers between the perovskite active layer 40 and the carbon electrode layer 50, thereby improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell and reducing the hysteresis effect. Moreover, the improvement of the interface contact between the perovskite active layer 40 and the carbon electrode layer 50 can effectively inhibit the infiltration of external moisture, thereby improving the stability of the carbon-based perovskite solar cell.

[0093] By comparing Examples 1 to 4, it can be seen that the applied pressure, the heating rate in the heating stage, the temperature and time in the insulation stage include but are not limited to the preferred range of the present application. Limiting them within the preferred range of the present application is beneficial to improving the binding force between the perovskite active layer 40 and the carbon electrode layer 50, and is beneficial to improving the extraction and transmission of hole carriers between the perovskite active layer 40 and the carbon electrode layer 50, thereby helping to improve the photoelectric conversion efficiency of carbon-based perovskite solar cells, and at the same time helping to reduce the hysteresis effect.

[0094] By comparing Examples 1, 5, and 6, it can be seen that the use of the pressure, the heating rate in the heating stage, and the temperature and time in the insulation stage within the above-mentioned preferred ranges is beneficial to further improving the binding force between the perovskite active layer 40 and the carbon electrode layer 50, and is beneficial to further improving the extraction and transmission of hole carriers between the perovskite active layer 40 and the carbon electrode layer 50, thereby further improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell, and at the same time is beneficial to further reducing the hysteresis effect.

[0095] By comparing Examples 1, 7 and 8, Examples 1, 9 and 10, and Examples 1, 11 and 12 respectively, it can be seen that for different types of perovskite active materials, adopting the above-mentioned preferred ranges of pressure, heating rate in the heating stage, temperature and time in the insulation stage is beneficial to further improve the binding force between the perovskite active layer 40 and the carbon electrode layer 50, and is beneficial to further improve the extraction and transmission of hole carriers between the perovskite active layer 40 and the carbon electrode layer 50, thereby further improving the photoelectric conversion efficiency of the carbon-based perovskite solar cell, and at the same time is beneficial to further reduce the hysteresis effect.

[0096] It should be noted that the terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the application described herein can, for example, be implemented in an order other than that described herein.

[0097] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for preparing a carbon-based perovskite solar cell, comprising the step of preparing a laminated structure, wherein the laminated structure comprises a transparent conductive substrate (10) and an electron transport layer (20), a mesoporous layer (30), a perovskite active layer (40) and a carbon electrode layer (50) sequentially stacked on the surface of the transparent conductive substrate, characterized in that: After the step of preparing the laminated structure, the preparation method includes: A Hoffman clamp is used to apply a pressure perpendicular to the stacked structure to the stacked structure while performing an annealing treatment to obtain the carbon-based perovskite solar cell; wherein the pressure is 10 to 100 Pa.

2. The method for preparing a carbon-based perovskite solar cell according to claim 1, wherein: The annealing process includes a heating stage, a heat preservation stage and a cooling stage.

3. The method for preparing a carbon-based perovskite solar cell according to claim 2, wherein: The heating rate in the heating stage is 6-10° C. / min, the temperature in the heat preservation stage is 40-65° C., and the heat preservation time is 2-12 minutes.

4. The method for preparing a carbon-based perovskite solar cell according to claim 1, wherein: The carbon electrode layer (50) is prepared by a scraping method.

5. The method for preparing a carbon-based perovskite solar cell according to claim 1, wherein: The thickness of the carbon electrode layer (50) is 5 to 20 μm.

6. The method for preparing a carbon-based perovskite solar cell according to claim 2, wherein: The perovskite active layer (40) is prepared by a two-step anti-solvent spin coating method.

7. The method for preparing a carbon-based perovskite solar cell according to claim 6, wherein: The thickness of the perovskite active layer (40) is 400-560 nm; and / or the material of the perovskite active layer (40) is Cs 1-x FA x PbI3, where FA is formamidine, 0.77≤x≤0.

82.

8. The method for preparing a carbon-based perovskite solar cell according to claim 6, wherein: When the material of the perovskite active layer (40) is Cs 0.21 FA 0.79 When PbI3 is used, the pressure is 55-60 Pa, the heating rate in the heating stage is 8-10°C / min, the temperature in the holding stage is 58-62°C, and the holding time is 8-12 min; When the material of the perovskite active layer (40) is Cs 0.23 FA 0.77 When PbI3 is used, the pressure is 20-55 Pa, the heating rate in the heating stage is 6-9°C / min, the temperature in the holding stage is 40-50°C, and the holding time is 4-8 min; When the material of the perovskite active layer (40) is Cs 0.19 FA 0.81 When PbI3 is used, the pressure is 65-100 Pa, the heating rate in the heating stage is 7-9°C / min, the temperature in the insulation stage is 46-60°C, and the insulation time is 2-5 min.

9. The method for preparing a carbon-based perovskite solar cell according to claim 2, wherein: When the thickness of the carbon electrode layer (50) is 5 to 10 μm, the pressure is 50 to 75 Pa, the heating rate in the heating stage is 6 to 7° C. / min, the temperature in the insulation stage is 54 to 62° C., and the insulation time is 8 to 12 minutes; When the thickness of the carbon electrode layer (50) is 13 to 20 μm, the pressure is 30 to 58 Pa, the heating rate in the heating stage is 6 to 9° C. / min, the temperature in the insulation stage is 47 to 60° C., and the insulation time is 7 to 11 minutes.

10. The method for preparing a carbon-based perovskite solar cell according to claim 6, wherein: The electron transport layer (20) is prepared by chemical bath deposition, spin coating or magnetron sputtering.

11. The method for preparing a carbon-based perovskite solar cell according to claim 1 or 10, wherein: The thickness of the electron transport layer (20) is 20 to 60 nm; and / or the material of the electron transport layer (20) is selected from one or more of the group consisting of titanium dioxide, tin dioxide and zinc oxide.

12. The method for preparing a carbon-based perovskite solar cell according to claim 6, wherein: The mesoporous layer (30) is prepared by a spin coating method.

13. The method for preparing a carbon-based perovskite solar cell according to claim 1 or 12, wherein: The thickness of the mesoporous layer (30) is 50 to 94 nm; and / or the material of the mesoporous layer (30) is selected from one or more of the group consisting of titanium dioxide, aluminum oxide, and zirconium oxide.

14. The method for preparing a carbon-based perovskite solar cell according to claim 6, wherein: The transparent conductive substrate (10) is selected from one or more of the group consisting of FTO conductive glass, ITO conductive glass and IZO conductive glass.

15. A carbon-based perovskite solar cell, characterized in that: The carbon-based perovskite solar cell is prepared by the preparation method of the carbon-based perovskite solar cell according to any one of claims 1 to 14.

Images