Perovskite solar cell containing double-layer trifluoroacetate modification layer and preparation method thereof
By introducing a bilayer trifluoroacetate modification layer into perovskite solar cells, the defects in the electron transport layer and the perovskite layer were solved, achieving efficient and stable photoelectric conversion, improving the energy level matching and stability of the device, and reducing commercialization costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HEBEI UNIV OF TECH
- Filing Date
- 2022-11-14
- Publication Date
- 2026-06-23
AI Technical Summary
Existing perovskite solar cells have defects in the electron transport layer and perovskite layer, resulting in low efficiency and poor stability. Existing modification materials can only modify a single interface, and multi-layer interface modification has problems such as complex processes, poor interface contact, and interlayer dissolution.
The electron transport layer and the perovskite layer are modified with a bilayer trifluoroacetate modification layer. Hydrogen bonds and chemical interactions are used to passivate oxygen defects in tin oxide and ion vacancies in the perovskite layer. Volatile solvents are used in the preparation process and the material is stored in an inert gas to avoid annealing.
This improved the open-circuit voltage, short-circuit current, and fill factor of perovskite solar cells, significantly enhancing the photoelectric conversion efficiency and stability of the cells and reducing commercialization costs.
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Figure CN115915795B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of perovskite solar energy technology, specifically relating to a perovskite solar cell with a double-layer trifluoroacetate modified layer and its preparation method. Background Technology
[0002] With the progress of social civilization, human demand for energy has increased dramatically. Existing energy supply systems, including fossil fuels such as coal, oil, and natural gas, have limited reserves and may cause irreversible damage to the environment. Developing clean and pollution-free new energy supply systems is essential. To a certain extent, solar energy is inexhaustible, widely distributed on Earth, and clean and pollution-free. The rational development and utilization of solar energy is a powerful means to respond to my country's national call to achieve energy conservation, emission reduction, and carbon neutrality goals.
[0003] Solar cells convert solar energy into electrical energy, and developing efficient and stable solar cells is one of the effective ways to utilize solar energy. In 2009, Professor Riki Miyasaka of Toin University in Yokohama, Japan, invented a perovskite solar cell with perovskite as the light-absorbing layer, achieving a power conversion efficiency of 3.8%. Thanks to the efforts of many scientists, the power conversion efficiency of perovskite solar cells has exceeded 25%. Perovskite solar cells have accomplished in a few decades what silicon-based solar cells took decades to achieve; therefore, perovskite solar cells are considered the next generation of photovoltaic technology. Typically, the electron transport layer and perovskite layer of a formally structured perovskite solar cell are prepared by annealing and evaporating the solvent from a precursor solution. During crystallization, defects easily arise at grain boundaries and surfaces. These defects lead to accelerated perovskite decomposition and non-radiative recombination, which severely negatively impacts the efficiency and stability of perovskite solar cells. If we can fill and modify the defects in the prepared electron transport layer and perovskite layer, effectively improving the stability and efficiency of perovskite solar cells, this could further accelerate their commercialization.
[0004] For example, CN 114843405 A discloses an electron transport layer for a perovskite solar cell modified with a chlorinated organopotassium salt, a perovskite solar cell, and a method for preparing the same, wherein the chlorinated organopotassium salt is uniformly distributed on the surface of the electron transport layer. CN111584715 A discloses a modifier, a perovskite active material, a preparation method, and a perovskite solar cell, which utilizes fullerene derivatives, polymethyl methacrylate, and organic ionic liquids to modify the perovskite layer. However, the interface modifiers in these inventions can only modify a single interface; dual-layer interface modification technology and candidate materials for dual-layer interface modification have not been disclosed. Summary of the Invention
[0005] The purpose of this invention is to address the limitation of existing modifying materials that can only modify defects at a single interface, by providing a perovskite solar cell with a bilayer trifluoroacetate modified layer and its fabrication method. This cell simultaneously fills and modifies defects in both the electron transport layer and the perovskite layer, passivating oxygen defects in tin oxide and ion vacancies in the perovskite layer through hydrogen bonding and chemical interactions. In the fabrication method, trifluoroacetate is selected as the modifying layer, and no annealing is required after deposition. This invention solves the problems of low efficiency and poor stability in perovskite solar cells due to numerous defects in the electron transport layer and perovskite layer.
[0006] The technical solution of this invention is as follows:
[0007] A perovskite solar cell containing a double-layer trifluoroacetate modified layer comprises, from bottom to top, conductive glass, an electron transport layer, an electron transport layer modified layer, a perovskite layer, a perovskite modified layer, a hole transport layer, and an electrode.
[0008] The conductive glass is ITO conductive glass or FTO conductive glass.
[0009] The electron transport layer is tin oxide with a thickness of 20-400 nm;
[0010] The perovskite layer is methylamine lead iodide perovskite with a thickness of 500-2000 nm;
[0011] The hole transport layer is Spiro-OMeTAD with a thickness of 20-400 nm;
[0012] The electron transport layer and the perovskite layer are both selected from methylamine trifluoroacetate, formamidine trifluoroacetate, dimethylamine trifluoroacetate, ethylamidine trifluoroacetate, ethylenediamine trifluoroacetate, and guanidine trifluoroacetate, with a thickness of 2-200 nm.
[0013] The electrode is a gold or silver electrode with a thickness of 10-100 nm;
[0014] The method for preparing the perovskite solar cell containing a double-layer trifluoroacetate modified layer specifically includes the following steps:
[0015] 1) After cleaning the conductive glass, apply ozone for 5-60 minutes;
[0016] 2) Spin-coat the tin oxide aqueous solution onto the conductive glass described in step 1), and anneal it at 100-400℃ for 10-90 min to obtain an electron transport layer;
[0017] The tin oxide aqueous solution has a mass percentage concentration of 3%-10%, a spin coating speed of 1000-4000 r / min, and a spin coating time of 5-100 s;
[0018] 3) Preheat the electron transport layer described in step 2) to 25-70°C;
[0019] 4) Spin-coat the electron transport layer modification solution onto the electron transport layer described in step 3), and place it in an inert gas for 1-10 days to obtain the electron transport layer modification layer;
[0020] The concentration of the electron transport layer modification solution is 0.1-10 mg / mL, and its solvent is chlorobenzene, anhydrous ethanol or isopropanol; the spin coating speed is 1000-5000 r / min, and the spin coating time is 10-50 s;
[0021] The inert gas is nitrogen, helium, or argon;
[0022] 5) Spin-coat the perovskite precursor solution onto the electron transport layer modification layer described in step 4), anneal at 100-200℃ for 10-100 min, and cool to room temperature to obtain the perovskite layer.
[0023] The solvent for the perovskite layer precursor solution is a mixed solvent composed of DMF and NMP in a ratio of 1:1 to 1:9;
[0024] The solute in the perovskite precursor solution is methylamine lead iodine, with a concentration of 1-2 mol / L. The spin coating speed is 2000-6000 r / min, and the spin coating time is 5-50 s.
[0025] 6) Preheat the perovskite layer obtained in step 5) to 25-70℃;
[0026] 7) Spin-coat the titanium ore interface modification layer solution onto the preheated perovskite layer described in step 6), and place it in an inert gas for 1-10 days to obtain the perovskite modification layer.
[0027] The concentration of the titanium ore interface modification layer solution is 0.1-10 mg / mL, and its solvent is chlorobenzene, anhydrous ethanol or isopropanol; the spin coating speed is 1000-5000 r / min, and the spin coating time is 10-50 s;
[0028] The inert gas is nitrogen, helium, or argon;
[0029] 8) Spin-coat the hole transport layer solution onto the perovskite modified layer obtained in step 7);
[0030] The solvent of the hole transport layer solution is chlorobenzene, with a concentration of 0.05-0.2 mg / mL, a spin coating speed of 2000-5000 r / min, and a spin coating time of 10-50 s;
[0031] 9) Place the hole transport layer described in step 8) in air or oxygen for 1-10 days, and then deposit a 5-100 nm metal electrode.
[0032] The essential features of this invention are:
[0033] Traditional perovskite solar cells typically consist of a conductive glass, an electron transport layer, a perovskite layer, a hole transport layer, and electrodes. To improve device efficiency and stability, modification layers are often added. However, previously disclosed materials are only effective for single-layer interfaces, and multi-layer interface modification suffers from complex processes, poor interfacial contact, and interlayer dissolution. Furthermore, annealing is required to allow the interface modification materials to passivate and for solvents to evaporate.
[0034] The perovskite solar cell structure of this invention comprises conductive glass, an electron transport layer, an electron transport layer modification layer, a perovskite layer, another perovskite modification layer, a hole transport layer, and electrodes. Specifically, a trifluoroacetate modification layer is introduced, which is effective for both the electron transport layer and the perovskite layer. This dual-modification layer structure not only reduces defects in both the electron transport layer and the perovskite layer but also improves the energy level matching between the layers. The matching of interface energy levels directly affects the carrier collection efficiency, thus influencing the final photoelectric conversion efficiency of the device. Energy level matching significantly improves the efficiency and stability of the device. Trifluoroacetate has a high binding energy and a low reaction barrier, enabling passivation at room temperature. The use of a volatile solvent and long-term storage under an inert gas environment ensures complete solvent evaporation, eliminating the need for post-annealing.
[0035] The beneficial effects of this invention are as follows:
[0036] A perovskite solar cell with a double-layer trifluoroacetate modified layer and its preparation method are disclosed. The purpose is to fill and modify the defects on the surface of the light-absorbing layer of the perovskite solar cell, thereby solving the problems of low efficiency and poor stability of perovskite solar cells. Compared with the prior art, the present invention has the following advantages:
[0037] This invention provides a perovskite solar cell with a double-layer trifluoroacetate modified layer and its preparation method. The modified layer does not require secondary annealing, resulting in a stable and defect-free perovskite solar cell with a double-layer interface modified layer. This effectively improves the quality of the electron transport layer and the perovskite layer, thereby increasing the open-circuit voltage, short-circuit current, and fill factor of the perovskite solar cell, thus significantly improving its efficiency and stability. A comparative example perovskite solar cell exhibits a photoelectric conversion efficiency of 20.12%, a fill factor of 78.34%, an open-circuit voltage of 1.10V, and a short-circuit current of 23.35mA / cm². 2 The perovskite solar cell in this example has a photoelectric conversion efficiency of 21.97%, a fill factor of 79.27%, an open-circuit voltage of 1.15V, and a short-circuit current of 24.10mA / cm. 2It can be observed that the open-circuit voltage, short-circuit current, and fill factor have been increased, resulting in a significant increase in efficiency. It has been reported that for every 1% increase in photoelectric conversion efficiency, the corresponding production capacity and revenue increase, and the corresponding cost per kilowatt-hour can decrease by 5%-7%. Therefore, this invention is of great significance for the commercialization of perovskite solar cells. Attached Figure Description
[0038] Figure 1 This is a structural diagram of a perovskite solar cell containing a double-layer trifluoroacetate modified layer. The diagram shows conductive glass 101, electron transport layer 102, electron transport layer modified layer 103, perovskite layer 104, perovskite modified layer 105, hole transport layer 106, and electrode 107.
[0039] Figure 2 This is a scanning electron microscope image of the interface modification layer containing methyltrifluoroacetate in Example 1.
[0040] Figure 3 This is a scanning electron microscope image of Comparative Example 1 without the perovskite interface modification layer.
[0041] Figure 4 The current-voltage curves are for the perovskite solar cells described in Comparative Example 1 (401) and Example 1 (402). Detailed Implementation
[0042] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the following embodiments. Unless otherwise specified, the methods described are conventional methods. Unless otherwise specified, the raw materials are all available from publicly available commercial sources.
[0043] Example 1: Preparation of perovskite solar cells with a bilayer methylamine trifluoroacetate modified layer and its preparation method
[0044] 1) Preparation stage: Clean the 19mm*19mm FTO conductive glass with ethanol by ultrasonic cleaning for 30 minutes, followed by ozone cleaning for 15 minutes.
[0045] 2) Preparation of electron transport layer: A 5% tin oxide aqueous solution was spin-coated onto the FTO conductive glass described in step 1) at a speed of 4000 r / min for 30 s, annealed at 160°C for 30 min, and naturally cooled to room temperature to obtain a tin oxide electron transport layer with a thickness of 80 nm; then the obtained tin oxide electron transport layer was preheated to 30°C.
[0046] 3) Preparation of electron transport layer modification layer: Spin-coat a 1 mg / mL trifluoroacetic acid methylamine isopropanol solution onto the electron transport layer described in step 2) at 3000 r / min for 30 s to obtain an electron transport layer modification layer with a thickness of 20 nm; then place the obtained electron transport layer modification layer in nitrogen for 2 days to remove the solvent.
[0047] 4) Preparation of perovskite layer: Dissolve methylamine lead iodine in DMF:NMP = 1:1 solvent at a concentration of 1.5 mol / L, shake for one hour to obtain perovskite layer precursor solution, spin coat the perovskite layer precursor solution onto the electron transport layer modification layer described in step 3) at 3000 r / min for 20 s, anneal at 105 °C for 90 min to obtain perovskite layer with a thickness of 800 nm, and cool to room temperature;
[0048] 5) Preparation of perovskite modification layer: The cooled perovskite layer described in step 4) is preheated to 30°C, and then a 1 mg / mL trifluoroacetic acid methylamine isopropanol solution is spin-coated onto the perovskite layer at 3000 r / min for 30 s to a thickness of 20 nm. The layer is then placed in nitrogen gas for 1 day.
[0049] 6) Preparation of hole transport layer: Spin-coat 0.1 mg / mL Spiro-OMeTAD hole transport layer chlorobenzene solution onto the perovskite modified layer described in step 6) at 3000 r / min for 30 s, with a thickness of 100 nm, and place it in air for one day to oxidize the hole transport layer.
[0050] 7) Preparation of metal electrodes: 20 nm gold electrodes were deposited using a vacuum thermal evaporator.
[0051] Example 2: Preparation of perovskite solar cells with a bilayer trifluoroacetic acid formamidinium-modified layer and its preparation method
[0052] The remaining steps are the same as in Example 1, except that the trifluoroacetic acid methylamine isopropanol solution in steps 3) and 5) is replaced with trifluoroacetic acid formamidin isopropanol solution.
[0053] Example 3: Preparation of perovskite solar cells with a bilayer dimethylamine trifluoroacetate modified layer and its preparation method
[0054] The remaining steps are the same as in Example 1, except that the trifluoroacetic acid methylamine isopropanol solution in steps 3) and 5) is replaced with trifluoroacetic acid dimethylamine isopropanol solution.
[0055] Example 4: Preparation of perovskite solar cells with a bilayer trifluoroacetic acid ethylenediamine modified layer and its preparation method
[0056] The remaining steps are the same as in Example 1, except that the trifluoroacetic acid methylamine isopropanol solution in steps 3) and 5) is replaced with trifluoroacetic acid ethylenediamine isopropanol solution.
[0057] Example 5: Preparation of a perovskite solar cell with a double-layer trifluoroacetate acetamidine modified layer and its preparation method. The remaining steps are the same as in Example 1, except that the trifluoroacetate methylamine isopropanol solution in steps 3) and 5) is replaced with trifluoroacetate acetamidine isopropanol solution.
[0058] Example 6: Preparation of perovskite solar cells with a bilayer trifluoroacetic acid guanidine modification layer and its preparation method
[0059] The remaining steps are the same as in Example 1, except that the trifluoroacetic acid methylamine isopropanol solution in steps 3) and 5) is replaced with trifluoroacetic acid guanidine isopropanol solution.
[0060] Example 7: Preparation of perovskite solar cells with a bilayer methylamine trifluoroacetate modified layer and its preparation method
[0061] The remaining steps are the same as in Example 1, except that the 1 mg / mL trifluoroacetic acid methylamine isopropanol solution in steps 3) and 5) is replaced with a 3 mg / mL trifluoroacetic acid methylamine ethanol solution, and the deposition thickness is 40 nm.
[0062] Example 8: Preparation of perovskite solar cells with a bilayer dimethylamine trifluoroacetate modified layer and its preparation method
[0063] The remaining steps are the same as in Example 1, except that the 1 mg / mL dimethylamine trifluoroacetate isopropanol solution in steps 3) and 5) is replaced with a 3 mg / mL dimethylamine trifluoroacetate ethanol solution, and the deposition thickness is 40 nm.
[0064] Example 9: Preparation of perovskite solar cells with a bilayer dimethylamine trifluoroacetate modified layer and its preparation method
[0065] The remaining steps are the same as in Example 1, except that the 1 mg / mL dimethylamine trifluoroacetate isopropanol solution in steps 3) and 5) is replaced with a 3 mg / mL dimethylamine trifluoroacetate ethanol solution, the spin coating parameters are changed to 4000 r / min for 40 s, and the deposition thickness is 40 nm.
[0066] Example 10: Preparation of perovskite solar cells with a bilayer dimethylamine trifluoroacetate modified layer and its preparation method
[0067] The remaining steps are the same as in Example 1, except that the 1 mg / mL dimethylamine trifluoroacetate isopropanol solution in steps 3) and 5) is replaced with a 5 mg / mL dimethylamine trifluoroacetate ethanol solution, the spin coating parameters are changed to 4000 r / min for 40 s, and the deposition thickness is 50 nm.
[0068] Example 11: Preparation of perovskite solar cells with a bilayer dimethylamine trifluoroacetate modified layer and its preparation method
[0069] The remaining steps are the same as in Example 1, except that the 1 mg / mL dimethylamine trifluoroacetate isopropanol solution in steps 3) and 5) is replaced with a 10 mg / mL dimethylamine trifluoroacetate ethanol solution, the spin coating parameters are changed to 4000 r / min for 40 s, and the deposition thickness is 80 nm.
[0070] Example 12: Preparation of perovskite solar cells with a bilayer dimethylamine trifluoroacetate modified layer and its preparation method
[0071] The remaining steps are the same as in Example 1, except that the 1 mg / mL dimethylamine trifluoroacetate isopropanol solution in steps 3) and 5) is replaced with a 10 mg / mL dimethylamine trifluoroacetate ethanol solution, the spin coating parameters are changed to 5000 r / min for 50 s, and the deposition thickness is 60 nm.
[0072] Comparative Example 1: Fabrication of perovskite solar cells without a bilayer interface modification layer
[0073] The remaining steps are the same as in Example 1, except that the interface modification material is not spin-coated in steps 3) and 5) to obtain the control solar cell.
[0074] The perovskite layers prepared in step 5) of the comparative example and Example 1 were observed using a JEOL 7610F scanning electron microscope. Figure 2 and Figure 3 It can be observed that the defects in the perovskite layer containing the modified layer are filled and passivated. At AM1.5, 100 mW / cm² 2 The JV performance curve of the battery was tested using the 7IS steady-state solar simulator from Beijing Saifan Optoelectronic Instruments Co., Ltd. under illumination conditions. Figure 4 As shown, tests revealed that the control example perovskite solar cell had a photoelectric conversion efficiency of 20.12%, a fill factor of 78.34%, an open-circuit voltage of 1.10V, and a short-circuit current of 23.35mA / cm². 2 The perovskite solar cell in this example has a photoelectric conversion efficiency of 21.97%, a fill factor of 79.27%, an open-circuit voltage of 1.15V, and a short-circuit current of 24.10mA / cm. 2 It can be observed that the modified perovskite solar cells exhibit significantly higher performance than the control cells.
[0075] As can be seen from the above embodiments, this invention introduces a trifluoroacetate modification layer that is effective for both the electron transport layer and the perovskite layer. This dual-modification layer structure not only reduces defects in both the electron transport layer and the perovskite layer but also improves the energy level matching between the layers. The matching of interface energy levels directly affects the carrier collection efficiency, thus influencing the final photoelectric conversion efficiency of the device. Energy level matching significantly improves the device's efficiency and stability. Trifluoroacetate has a high binding energy and a low reaction barrier, allowing for passivation at room temperature. The use of a volatile solvent and long-term storage under an inert gas atmosphere ensures complete solvent evaporation, eliminating the need for post-annealing.
[0076] Matters not covered in this invention are common knowledge.
Claims
1. A perovskite solar cell containing a double-layer trifluoroacetate modified layer, characterized in that: The battery consists of, from bottom to top, conductive glass, an electron transport layer, an electron transport layer modification layer, a perovskite layer, a perovskite modification layer, a hole transport layer, and electrodes. The electron transport layer and the perovskite layer are both selected from methylamine trifluoroacetate, formamidine trifluoroacetate, dimethylamine trifluoroacetate, ethylamidine trifluoroacetate, ethylenediamine trifluoroacetate, and guanidine trifluoroacetate, with a thickness of 2-200 nm.
2. The perovskite solar cell with a double-layer trifluoroacetate modified layer as described in claim 1, characterized in that the conductive glass is ITO conductive glass or FTO conductive glass; The electron transport layer is tin oxide with a thickness of 20-400 nm; The perovskite layer is methylamine lead iodide perovskite with a thickness of 500-2000 nm; The hole transport layer is Spiro-OMeTAD with a thickness of 20-400 nm; The electrode is a gold or silver electrode with a thickness of 10-100 nm.
3. The method for preparing a perovskite solar cell with a bilayer trifluoroacetate modified layer as described in claim 1, characterized in that: Includes the following steps: 1) After cleaning the conductive glass, ozone for 5-60 minutes; 2) Spin-coat the tin oxide solution onto the conductive glass described in step 1), and anneal it at 100-400℃ for 10-90 min to obtain an electron transport layer; The tin oxide aqueous solution has a mass percentage concentration of 3%-10%; the spin coating speed is 1000-4000 r / min, and the spin coating time is 5-100 s; 3) Preheat the electron transport layer described in step 2) to 25-70°C; 4) Spin-coat the electron transport layer modification solution onto the electron transport layer described in step 3), and place it in an inert gas for 1-10 days to obtain the electron transport layer modification layer; The concentration of the electron transport layer modification solution is 0.1-10 mg / mL, and its solvent is chlorobenzene, anhydrous ethanol or isopropanol; the spin coating speed is 1000-5000 r / min, and the spin coating time is 10-50 s; 5) Spin-coat the perovskite layer precursor solution onto the electron transport layer modification layer described in step 4), anneal at 100-200℃ for 10-100 min, and cool to room temperature to obtain the perovskite layer. The solvent for the perovskite layer precursor solution is a mixed solvent composed of DMF and NMP in a ratio of 1:1 to 1:9; The solute in the perovskite precursor solution is methylamine lead iodine, with a concentration of 1-2 mol / L; the spin coating speed is 2000-6000 r / min, and the spin coating time is 5-50 s; 6) Preheat the perovskite layer obtained in step 5) to 25-70℃; 7) Spin-coat the titanium ore interface modification layer solution onto the preheated perovskite layer described in step 6), and place it in an inert gas for 1-10 days to obtain the perovskite modification layer. The concentration of the titanium ore interface modification layer solution is 0.1-10 mg / mL, and its solvent is chlorobenzene, anhydrous ethanol or isopropanol; the spin coating speed is 1000-5000 r / min, and the spin coating time is 10-50 s; 8) Spin-coat the hole transport layer solution onto the perovskite modified layer obtained in step 7); The solvent of the hole transport layer solution is chlorobenzene, with a concentration of 0.05-0.2 mg / mL, a spin coating speed of 2000-5000 r / min, and a spin coating time of 10-50 s; 9) Place the hole transport layer described in step 8) in air or oxygen for 1-10 days, and then deposit a 5-100nm metal electrode.
4. The method for preparing a perovskite solar cell with a double-layer trifluoroacetate modified layer as described in claim 3, characterized in that: The inert gas mentioned in steps 4) and 7) is nitrogen, helium or argon.