FAPbI3 perovskite active layer precursor solution and solar cell
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA THREE GORGES CORPORATION
- Filing Date
- 2026-01-26
- Publication Date
- 2026-04-21
Smart Images
Figure CN121908789A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of perovskite solar cell technology, specifically relating to a FAPbI3 perovskite active layer precursor solution and a solar cell. Background Technology
[0002] Organic-inorganic hybrid perovskite solar cells, as a novel green energy power generation technology, have attracted widespread attention due to their high photoelectric conversion efficiency, large-area solution processing capability, and ability to be combined with silicon solar cells to fabricate tandem solar cells. As a research hotspot in the field of solar power generation, the photoelectric conversion efficiency of perovskite solar cells has increased from the initial 3.8% to 27% in just over a decade, demonstrating broad application prospects.
[0003] Perovskite solar cells with an active layer structure of FAPbI3 are among the most promising types of perovskite solar cells due to their high photoelectric conversion efficiency and good thermal stability. However, on the one hand, the crystal phase generated during the preparation of the active layer in FAPbI3 perovskite solar cells is unstable, and its α phase easily transforms into a non-photovoltaic yellow phase, making it impossible to prepare a photovoltaic active layer film. Consequently, the photovoltaic devices produced cannot achieve photoelectric conversion or have extremely low photoelectric conversion efficiency. On the other hand, the widely used perovskite polycrystalline ionic thin films are mostly prepared based on solution processing technology. This process has the advantage of significantly lower cost; however, the crystallization process of this technology has weak controllability and is prone to problems such as excessively fast crystallization rates. This results in poor film morphology and excessively high perovskite grain boundary defect state density, which increases non-radiative energy loss and affects the photoelectric conversion efficiency and stability of perovskite solar cell devices. Summary of the Invention
[0004] Therefore, the technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art, thereby providing a FAPbI3 perovskite active layer precursor solution and a solar cell.
[0005] Therefore, the present invention provides the following technical solution:
[0006] In a first aspect, the present invention provides a FAPbI3 perovskite active layer precursor solution, which is prepared by dissolving phenyl 4-chloroisothiocyanate, lead iodide, formamidinium hydroiodate, and methylamine hydrochloride in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide. The concentration of phenyl 4-chloroisothiocyanate in the FAPbI3 perovskite active layer precursor solution is 0.1~2 mg / mL.
[0007] Optionally, in the FAPbI3 perovskite active layer precursor solution, the lead iodide concentration is 1.5~2.0 mmol / mL, the molar ratio of lead iodide:formamidinium hydroiodate:methylamine hydrochloride is 3:3:1, and the volume ratio of N,N-dimethylformamide to dimethyl sulfoxide is 5:1~10:1.
[0008] Optionally, the FAPbI3 perovskite active layer is prepared by dropping the FAPbI3 perovskite active layer precursor liquid onto a substrate, adding an antisolvent onto the rotating substrate, and annealing.
[0009] Optionally, the rotation speed during the preparation of the FAPbI3 perovskite active layer is 2000rpm~8000rpm, the rotation time is 30s~80s, and the antisolvent is added 5~40s after the start of rotation.
[0010] Optionally, the antisolvent is selected from at least one of chlorobenzene, diethyl ether, acetone, toluene, ethyl acetate, or chloroform.
[0011] Optionally, the annealing temperature during the preparation of the FAPbI3 perovskite active layer is 100℃~180℃, the annealing time is 10min~60min, the annealing atmosphere is air, and the air humidity is 20%~50%.
[0012] Optionally, the thickness of the FAPbI3 perovskite active layer is 300 nm to 1500 nm.
[0013] In a second aspect, the present invention provides a FAPbI3 perovskite solar cell, comprising a transparent conductive substrate layer, an electron transport layer, a FAPbI3 perovskite active layer, a passivation layer, a hole transport layer, and a metal back electrode arranged sequentially.
[0014] Specifically, the preparation method of the FAPbI3 perovskite solar cell provided by the present invention can be described in the following steps: Step 1: Clean the FTO glass substrate with deionized water, acetone and isopropanol in sequence using ultrasonic cleaning. Then blow away the solvent remaining on the glass substrate with nitrogen gas to obtain a clean transparent conductive substrate. Step 2: After cleaning the conductive substrate in Step 1 and treating it with UVO, place it on a spin coater. Use a pipette to draw up the tin dioxide nanocrystal solution and spread it evenly on the substrate surface. Start the spin coater to rotate at high speed. After the rotation stops, place the substrate on a hot plate and anneal it in air to obtain the electron transport layer. Step 3: After UVO treatment of the substrate obtained in step 2, place it on a spin coater in the glove box. Use a pipette to draw up the prepared FAPbI3 perovskite active layer precursor solution and evenly coat it on the surface of the electron transport layer. Start the spin coater to rotate at high speed and add antisolvent. After the rotation stops, place it on a hot stage for annealing in air to obtain the FAPbI3 perovskite active layer. Step 4: Place the substrate from Step 3 on the spin coater inside the glove box, use a pipette to draw up the prepared passivation layer solution, and evenly coat it on the surface of the active layer. Start the spin coater to rotate at high speed. After the rotation stops, place the substrate on the hot plate inside the glove box for annealing to obtain the passivation layer. Step 5: Place the substrate from Step 4 on the spin coater inside the glove box. Use a pipette to draw up the prepared hole transport layer solution and spread it evenly on the surface of the passivation layer. Start the spin coater to rotate at high speed. After the rotation stops, the hole transport layer is obtained. Step 6: A metal back electrode is fabricated on the hole transport layer on the substrate of Step 5 using a thermal evaporation method.
[0015] Furthermore, the ultrasonic cleaning time for each solvent in step 1 is 10 min to 30 min.
[0016] Furthermore, in step 2, the spin coater speed is 3000rpm~8000rpm, the rotation time is 15s~60s, the hot plate annealing temperature is 100℃~180℃, and the annealing time is 15min~60min.
[0017] Furthermore, in step 3, the volume of FAPbI3 perovskite active layer precursor liquid aspirated by the pipette for each substrate (2cm×2cm) is 20μL~100μL.
[0018] Furthermore, in step 4, the annealing temperature on the hot plate is 80℃~180℃, and the annealing time is 5min~60min.
[0019] Furthermore, in step 5, the volume of hole transport layer solution aspirated by the pipette for each substrate (2cm×2cm) is 30μL~80μL, the spin coater speed is 3000rpm~8000rpm, and the rotation time is 30s~60s.
[0020] Furthermore, in step 6, the pressure inside the vapor deposition chamber during vapor deposition is 9 × 10⁻⁶. -5 Pa, the thickness of molybdenum oxide is 8 nm, and the thickness of the metal Ag electrode is 80 nm to 120 nm.
[0021] The technical solution of this invention has the following advantages: This invention provides a FAPbI3 perovskite active layer precursor solution and a solar cell. Compared with the prior art, this invention adds an auxiliary phase-forming material, phenyl 4-chloroisothiocyanate, to the FAPbI3 perovskite precursor solution during the preparation of the FAPbI3 perovskite active layer. This invention has the following beneficial technical effects: phenyl 4-chloroisothiocyanate contains various functional groups, including chlorine atoms, thiocarbonyl groups, and cyano groups. On the one hand, it can interact with lead-iodine octahedra in the solution, reducing the generation of harmful intermediate phases, regulating the nucleation and crystallization process of perovskite, improving film quality, and fundamentally reducing the defect state density of perovskite crystals. On the other hand, during the crystallization process, phenyl 4-chloroisothiocyanate molecules fully penetrate to the perovskite grain boundaries. These functional groups can passivate different types of defects, reduce the defect state density, reduce non-radiative energy loss, and improve the photoelectric conversion efficiency and stability of the device.
[0022] The method for preparing FAPbI3 perovskite solar cells provided by this invention is simple, has mild and easily controllable conditions, and has broad application prospects. Attached Figure Description
[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0024] Figure 1 This is a schematic diagram of the structure of the FAPbI3 perovskite solar cell provided by the present invention; Figure 2 The FAPbI3 perovskite solar cells provided in Examples 1-3 of this invention J - V Line graph; Figure 3 The FAPbI3 perovskite solar cells provided in Embodiment 1 and Comparative Example 1 of this invention J - V Line graph; Figure 4 This is a graph showing the normalized power conversion efficiency of the FAPbI3 perovskite solar cells provided in Examples 1-3 and Comparative Example 1 of the present invention as a function of time.
[0025] Figure label: 1. Transparent conductive substrate layer; 2. Electron transport layer; 3. FAPbI3 perovskite active layer; 4. Passivation layer; 5. Hole transport layer; 6. Metal back electrode. Detailed Implementation
[0026] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.
[0027] Where specific experimental steps or conditions are not specified in the examples, they can be performed according to the conventional experimental steps or conditions described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.
[0028] This invention provides a FAPbI3 perovskite active layer precursor solution and a solar cell. The FAPbI3 perovskite active layer precursor solution containing phenyl 4-chloroisothiocyanate is coated onto a substrate on which an electron transport layer has been prepared. An antisolvent is then dropped onto the rapidly rotating substrate. After the rotation stops, the substrate is annealed in air to obtain the FAPbI3 perovskite active layer. A schematic diagram of the FAPbI3 perovskite solar cell provided by this invention is shown below. Figure 1 As shown, it includes a transparent conductive substrate layer 1, an electron transport layer 2, a FAPbI3 perovskite active layer 3, a passivation layer 4, a hole transport layer 5, and a metal back electrode 6, which are arranged sequentially.
[0029] The method for fabricating FAPbI3 perovskite solar cells provided by this invention includes the following steps: An electron transport layer, a FAPbI3 perovskite active layer, a passivation layer, a hole transport layer, and a metal back electrode are sequentially formed on the surface of a transparent conductive substrate to obtain a FAPbI3 perovskite solar cell. The method for preparing the FAPbI3 perovskite active layer is as follows: a FAPbI3 perovskite active layer precursor solution containing phenyl 4-chloroisothiocyanate is coated on a substrate on which an electron transport layer has been prepared; an antisolvent is dropped onto a substrate that is rotating at high speed; after the rotation stops, the substrate is annealed in an air environment to obtain the FAPbI3 perovskite active layer.
[0030] In this invention, the transparent conductive substrate is preferably ITO glass, FTO glass, AZO glass, or conductive PET, and more preferably FTO glass. This invention does not impose any special restrictions on the source of the transparent conductive substrate; commercially available products well-known to those skilled in the art can be used. In this invention, the transparent conductive substrate is preferably cleaned with deionized water, acetone, and isopropanol for 15-30 minutes each before use, and then dried with a nitrogen gun.
[0031] In this invention, the electron transport layer is preferably SnO2 or TiO2. x NiOx CuO x CuSCN, CuPc or C 60 The electron transport layer and its derivatives, more preferably SnO2, are used. The thickness of the electron transport layer is preferably 10 nm to 200 nm, more preferably 20 nm to 100 nm. This invention does not impose any particular limitation on the method for forming the electron transport layer on the conductive substrate; any electron transport layer preparation method well known to those skilled in the art can be used.
[0032] In this invention, the solvent of the FAPbI3 perovskite active layer precursor solution is preferably one or more of DMF and DMSO. More preferably, the solvent of the FAPbI3 perovskite precursor solution is a mixed solvent of DMF and DMSO, with a volume ratio of DMF:DMSO = 7:1. The concentration of the FAPbI3 perovskite active layer precursor solution is preferably 1 mol / L to 2 mol / L. More preferably, the concentration of the FAPbI3 perovskite active layer precursor solution is 1.8 mol / L. Based on this, any FAPbI3 perovskite precursor solution known to those skilled in the art capable of forming the FAPbI3 perovskite precursor solution film can be used. Those skilled in the art have no particular restrictions on the preparation method of the FAPbI3 perovskite precursor solution.
[0033] In this invention, the antisolvent is preferably one or more of chlorobenzene, diethyl ether, acetone, toluene, ethyl acetate and chloroform, more preferably chlorobenzene.
[0034] In this invention, the preferred method for preparing the FAPbI3 perovskite active layer is a one-step spin coating method. The preferred preparation process is as follows: After UVO treatment of a substrate (2cm×2cm) for 10 minutes, it is placed on a spin coater in a glove box. Using a pipette, 30μL~60μL of the prepared FAPbI3 perovskite active layer precursor solution containing phenyl 4-chloroisothiocyanate is drawn and uniformly coated on the substrate surface. The spin coater is started and rotated at high speed (3000rpm~6000rpm) for 30~60s. 25~40s after the start of rotation, 300μL~2000μL of antisolvent is added dropwise. After the rotation stops, the substrate is placed on a hot plate and annealed in air at a temperature of 100℃~150℃ for 10min~30min and an air humidity of 30%~40%. After annealing, the FAPbI3 perovskite active layer is obtained.
[0035] In this invention, the thickness of the FAPbI3 perovskite active layer is preferably 100nm~2000nm, more preferably 300nm~1500nm.
[0036] In this invention, the hole transport layer is preferably Spiro-OMeTAD, P3HT, PTAA, or MnO.x WO x Alternatively, a 2PACz layer may be used, more preferably a Spiro-OMeTAD layer; the thickness of the hole transport layer is preferably 20 nm to 400 nm, more preferably 100 nm to 200 nm. This invention does not impose any particular limitation on the method for forming the hole transport layer on the FAPbI3 perovskite active layer; any hole transport layer preparation method well-known to those skilled in the art can be used.
[0037] This invention does not impose any special limitations on the type or formation method of the counter electrode; any technique well-known to those skilled in the art for forming the counter electrode on the hole transport layer can be used. In a preferred embodiment of this invention, the substrate after the hole transport layer has been prepared is transferred to a thermal evaporation equipment, where the vacuum level reaches 9 × 10⁻⁶. -5 Under the condition of Pa, molybdenum oxide is deposited by vapor deposition to a thickness of 8 nm, and then electrode (Ag) is deposited by vapor deposition to a thickness of 100 nm; after the vapor deposition is completed, FAPbI3 perovskite solar cell is obtained.
[0038] This invention provides a FAPbI3 perovskite active layer precursor solution and its solar cell. The preparation method is as follows: A FAPbI3 perovskite active layer precursor solution containing phenyl 4-chloroisothiocyanate is coated onto a substrate on which an electron transport layer has been prepared. An antisolvent is then dropped onto the rapidly rotating substrate. After the rotation stops, the substrate is annealed in air to obtain the FAPbI3 perovskite active layer. An electron transport layer, a FAPbI3 perovskite active layer, a passivation layer, a hole transport layer, and a metal back electrode are sequentially formed on the surface of a transparent conductive substrate to obtain a FAPbI3 perovskite solar cell. Compared with existing methods, this invention has the following beneficial technical effects: 4-Chloroisothiocyanate phenyl ester contains various functional groups, including chlorine atoms, thiocarbonyl groups, and cyano groups. On the one hand, it can interact with lead-iodine octahedrons in solution, reducing the generation of harmful intermediate phases, regulating the nucleation and crystallization process of perovskite, improving film quality, and fundamentally reducing the defect state density of perovskite crystals. On the other hand, during the crystallization process, 4-chloroisothiocyanate phenyl ester molecules fully penetrate to the perovskite grain boundaries. These functional groups can passivate different types of defects, reduce the defect state density, reduce non-radiative energy loss, and improve the photoelectric conversion efficiency and stability of the device. Furthermore, the preparation method provided by this invention is simple, with mild and easily controllable conditions, and has broad application prospects.
[0039] To further illustrate the present invention, the following embodiments will be described in detail.
[0040] Example 1 This embodiment provides a solar cell prepared using a FAPbI3 perovskite active layer precursor solution. Its composition and specific preparation method are as follows: Step 1: Place the FTO transparent conductive glass substrate (2cm×2cm) in deionized water, acetone and isopropanol and ultrasonically clean it twice for 15min each. After drying with nitrogen, store it for later use.
[0041] Step 2: Dilute the tin dioxide (SnO2) stock solution with ultrapure water at a volume ratio of 1:5 and stir thoroughly to obtain a SnO2 precursor solution; place the FTO substrate in an ultraviolet ozone cleaner for 15 min; take 50 μL of SnO2 precursor solution and spread it evenly on the surface of the FTO conductive glass, and set the spin coater parameters to 3000 rpm / s and 30 s; then place it on a 150℃ hot stage in air environment for annealing for 30 min to obtain a SnO2 film (30 nm); place the SnO2 film prepared above in an ultraviolet ozone cleaner for 15 min for subsequent spin coating.
[0042] Step 3: Place the substrate obtained in Step 2 on a spin coater in the glove box. Use a pipette to draw 50 μL of the prepared FAPbI3 perovskite precursor solution (4-chloroisothiocyanate, PbI2, FAI, and MACl dissolved in a mixed solvent of DMF and DMSO, with a molar ratio of PbI2:FAI:MACl = 3:3:1 and a volume ratio of DMF:DMSO = 7:1; the concentration of FAPbI3 is 1.8 mol / L, and the concentration of 4-chloroisothiocyanate is 1.0 mg / mL), and evenly coat it onto the substrate surface. Start the spin coater at high speed (5000 rpm) for 60 s. Add 200 μL of chlorobenzene antisolvent 30 s after the start of rotation. After the rotation stops, place the substrate on a hot plate for annealing in air at 120℃ for 60 seconds. At a humidity of 40%, an FAPbI3 perovskite active layer (400 nm) was obtained after annealing.
[0043] Step 4: Place the substrate on a spin coater inside the glove box. Use a pipette to draw 50 μL of the prepared phenylethyl ammonium iodide (PEAI) solution (isopropanol solvent, concentration 2.0 mg / mL) and spread it evenly on the substrate surface. Start the spin coater to rotate at high speed of 5000 rpm for 30 seconds. After the rotation stops, place the substrate on a hot plate inside the glove box for annealing at 100℃ for 10 minutes. After annealing, a passivation layer is obtained.
[0044] Step 5: Take 60 μL of Spiro-OMeTAD solution (prepared by dissolving 90 mg Spiro-OMeTAD, 21 μL of LiTFSI solution (520 mg Li-TFSI dissolved in 1 mL of acetonitrile), 39 μL of 4-tert-butylpyridine, and 15 μL of Co(III)TFSI (300 mg Co(III)TFSI dissolved in 1 mL of acetonitrile) in 1 mL of chlorobenzene solvent) and spin coat it onto the prepared FAPbI3-based perovskite film. Set the spin coater parameters to 5000 rpm / s and 30 s to obtain the hole transport layer.
[0045] Step 6: Finally, perform vapor deposition using a high-vacuum evaporation equipment, with a pressure of 9 × 10⁻⁶ ppm inside the deposition chamber. -5 Pa, first evaporates an 8 nm thick layer of molybdenum oxide, then evaporates a 100 nm thick metal Ag electrode to obtain a FAPbI3 perovskite solar cell device.
[0046] Example 2 This embodiment provides a FAPbI3 perovskite solar cell, which differs from Example 1 in that the concentration of phenyl 4-chloroisothiocyanate in step 3 is 0.5 mg / mL.
[0047] Example 3 This embodiment provides a FAPbI3-based perovskite solar cell, which differs from Example 1 in that the concentration of phenyl 4-chloroisothiocyanate in step 3 is 1.5 mg / mL.
[0048] Comparative Example 1 This comparative example provides a FAPbI3 perovskite solar cell. The difference from Example 1 is that phenyl 4-chloroisothiocyanate is not added to the FAPbI3 perovskite active layer precursor solution when preparing the FAPbI3 perovskite active layer in step 3.
[0049] Test Example 1 The performance of the FAPbI3 perovskite solar cells provided in the embodiments and comparative examples of this invention was tested. The specific test methods are as follows: The current density-voltage ratio of FAPbI3 perovskite solar cells prepared in the PCE test examples and comparative examples was measured. JV The curve was tested on a Kethley 2400 system under the following conditions: simulated light intensity of 100 mW / cm². -2 (AM1.5G) Scan rate is 0.1V s -1(Step size 0.02V, time delay 200ms), scan range 1.2V to -0.2V, xenon lamp power output calibrated by NERL (National Renewable Energy Laboratory) standard KG5 Si cell.
[0050] Stability testing was conducted on unencapsulated FAPbI3 perovskite solar cell devices at room temperature in a nitrogen glove box.
[0051] The specific test results are shown in the table below: Table 1
[0052] From the examples and comparative examples Figure 2-4 As shown in Table 1, in the preparation of the FAPbI3 perovskite active layer, phenyl 4-chloroisothiocyanate was dissolved in the FAPbI3 perovskite active layer precursor solution (Examples 1-3). Compared to devices prepared without this auxiliary phase-forming material (Comparative Example 1), the photoelectric properties of the prepared FAPbI3 perovskite solar cell devices were improved in terms of open-circuit voltage, short-circuit current density, and fill factor. Figure 4 It is evident that the FAPbI3 perovskite solar cell device prepared using the method of this invention has the advantages of high photoelectric conversion efficiency and strong stability.
[0053] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A FAPbI3 perovskite active layer precursor solution, characterized in that, The FAPbI3 perovskite active layer precursor solution was prepared by dissolving phenyl 4-chloroisothiocyanate, lead iodide, formamidinium hydroiodate, and methylamine hydrochloride in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide; the concentration of phenyl 4-chloroisothiocyanate in the FAPbI3 perovskite active layer precursor solution was 0.1~2 mg / mL.
2. The FAPbI3 perovskite active layer precursor solution according to claim 1, characterized in that, In the FAPbI3 perovskite active layer precursor solution, the lead iodide concentration is 1.5~2.0 mmol / mL, the molar ratio of lead iodide:formamidin hydroiodate:methylamine hydrochloride is 3:3:1, and the volume ratio of N,N-dimethylformamide to dimethyl sulfoxide is 5:1~10:
1.
3. A FAPbI3 perovskite active layer, characterized in that, The FAPbI3 perovskite active layer is prepared by dropping the FAPbI3 perovskite active layer precursor liquid of claim 1 or 2 onto a substrate, dropping an antisolvent onto a rotating substrate, and annealing.
4. The FAPbI3 perovskite active layer according to claim 3, characterized in that, The FAPbI3 perovskite active layer was prepared by rotating at a speed of 2000 rpm to 8000 rpm for a time of 30 s to 80 s, and the antisolvent was added 5 to 40 s after the start of rotation.
5. The FAPbI3 perovskite active layer according to claim 3, characterized in that, The antisolvent is selected from at least one of chlorobenzene, diethyl ether, acetone, toluene, ethyl acetate, or chloroform.
6. The method for preparing the FAPbI3 perovskite active layer according to claim 3, characterized in that, The FAPbI3 perovskite active layer was prepared by annealing at a temperature of 100℃~180℃ for 10min~60min, in an air environment with a humidity of 20%~50%.
7. The FAPbI3 perovskite active layer according to claim 3 is characterized in that, The thickness of the FAPbI3 perovskite active layer is 300 nm to 1500 nm.
8. A FAPbI3 perovskite solar cell, characterized in that, The FAPbI3 perovskite solar cell comprises a transparent conductive substrate layer, an electron transport layer, a FAPbI3 perovskite active layer, a passivation layer, a hole transport layer, and a metal back electrode arranged sequentially.