A perovskite solar cell doped with carbonyl and nitrogen-containing organic small molecules and its preparation method thereof
By adding N,N-methylenedicarboxamide, a small organic molecule containing carbonyl and nitrogen, to the perovskite light-absorbing layer, the complexity of perovskite solar cell manufacturing and the problem of PbI2 residue were solved, and efficient and low-cost perovskite solar cell fabrication was achieved.
Patent Information
- Application Number
- CN202510071795.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-16
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2045-01-16
AI Technical Summary
Existing perovskite solar cell manufacturing processes are complex, require nitrogen conditions, resulting in high costs, and residual PbI2 affects photovoltaic performance and stability.
Adding carbonyl and nitrogen-containing organic small molecules, such as N,N-methylenedicarboxamide, to the perovskite light-absorbing layer can adjust the morphology of the PbI2 film, form a uniform porous film, reduce PbI2 residue, and improve crystallinity and carrier lifetime.
This invention achieves high photoelectric conversion efficiency and low cost perovskite solar cells, suitable for mass production, and features high short-circuit current density, high open-circuit voltage, and high fill factor.
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Figure CN119968008B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of perovskite solar cell technology, specifically to a perovskite solar cell doped with organic small molecules containing carbonyl and nitrogen groups and its preparation method. Background Technology
[0002] Perovskite solar cells have become promising competitors in photovoltaic devices due to their superior photoelectric properties and low-cost solution processing. However, the nitrogen conditions required for most high-efficiency perovskite solar cells complicate the device manufacturing process, increase costs, and pose significant challenges to the fabrication of perovskite thin films. Therefore, open-air manufacturing has become a trend in the commercialization of perovskite photovoltaics due to its low cost.
[0003] Two-step sequential solution deposition is a common strategy for preparing perovskite thin films with excellent photovoltaic performance. In this method, lead iodide (PbI2) crystals pre-deposited on the substrate react with subsequently deposited organic amine salts to form the perovskite phase. However, the dense PbI2 film in this method hinders the intercalation reaction between PbI2 and organic cations to some extent, and also results in a large amount of PbI2 remaining at the bottom of the perovskite film. Residual PbI2 is considered a double-edged sword in perovskite films; a small amount of PbI2 is beneficial to photovoltaic performance, but an excess leads to a decrease in photovoltaic performance and stability. Under illumination, PbI2 decomposes into metallic lead (Pb). 0 ) and I2. Pb 0 Residual PbI2 also acts as a recombination center for charge carriers, leading to increased nonradiative recombination and decreased stability. Therefore, removing residual PbI2 is essential for reducing internal defects, thereby producing high-quality perovskite thin films and high-performance perovskite solar cells, which could potentially accelerate the commercialization of perovskite solar cells. Summary of the Invention
[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of this invention is to provide an organic small molecule doped perovskite solar cell containing carbonyl and nitrogen and its preparation method.
[0005] This invention prepares a doped perovskite solar cell with high photoelectric conversion efficiency and high stability by adding a small organic molecule containing carbonyl and nitrogen to the perovskite light-absorbing layer.
[0006] The objective of this invention is achieved by at least one of the following technical solutions.
[0007] The present invention provides a carbonyl and nitrogen-containing organic small molecule doped perovskite solar cell, which, from bottom to top, comprises: a cathode substrate, an electron transport layer, a carbonyl and nitrogen-containing organic small molecule doped perovskite light-absorbing layer, a hole transport layer, and an anode electrode.
[0008] The carbonyl and nitrogen-containing organic small molecule-doped perovskite light-absorbing layer is composed of perovskite doped with carbonyl and nitrogen-containing organic small molecules.
[0009] Furthermore, the small organic molecule containing carbonyl and nitrogen is N,N-methylenedicarboxamide.
[0010] Furthermore, the carbonyl and nitrogen-containing organic small molecule-doped perovskite light-absorbing layer is a perovskite material doped with carbonyl and nitrogen-containing organic small molecules, wherein the perovskite material has ABX m Y 3-m The perovskite material has a structure in which A is at least one of CH3NH3 and C4H9NH3, B is at least one of Pb and Sn, X and Y are each independently Cl, Br or I, and m is 1, 2 or 3; the mass ratio of the small organic molecule containing carbonyl and nitrogen to the B-site element is 0.3%-3.5%;
[0011] More preferably, the perovskite material is FA. 0.98 MA 0.02 PbI3.
[0012] Furthermore, the thickness of the organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen is 400–800 nm.
[0013] Furthermore, the cathode substrate is selected from indium tin oxide glass (ITO glass) or fluorine-doped tin oxide glass (FTO glass).
[0014] Furthermore, the electron transport layer is a TiO2 or SnO2 thin film; the thickness of the electron transport layer is 30–50 nm;
[0015] Further, the hole transport layer is at least one of NiO, CuO, CuSCN, CuI, tungsten trioxide, molybdenum trioxide, vanadium pentoxide, Spiro-OMeTAD, P3HT, PTAA, NPB, and TPD; the thickness of the hole transport layer is 30–100 nm.
[0016] More preferably, the hole transport layer is Spiro-OMeTAD.
[0017] Furthermore, the anode electrode is Au, and its thickness is [missing information].
[0018] More preferably, the anode electrode is gold, with a thickness of [missing information].
[0019] The method for preparing the above-mentioned perovskite solar cell containing carbonyl and nitrogen organic small molecules provided by the present invention includes the following steps:
[0020] (1) Clean the cathode substrate and then perform surface treatment on the cathode substrate to obtain a surface-treated cathode surface;
[0021] (2) On the cathode surface after surface treatment in step (1), an electron transport layer, an organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen and a hole transport layer are sequentially spin-coated.
[0022] (3) An anode electrode is deposited on the surface of the hole transport layer described in step (2) to obtain the organic small molecule doped perovskite solar cell containing carbonyl and nitrogen.
[0023] Further, in step (1), the cathode substrate treatment includes: firstly, ultrasonically cleaning the cathode substrate sequentially with detergent, deionized water, acetone, anhydrous ethanol, and isopropanol for 15-20 minutes each; then drying it in a vacuum drying oven at 70-90℃; and finally, performing plasma surface treatment on the cleaned and dried cathode substrate surface for 10-20 minutes.
[0024] Further, the preparation of the electron transport layer in step (2) includes: spin-coating an aqueous SnO2 solution onto the surface of the surface-treated cathode substrate at 1000-5000 rpm for 30-50 s; then annealing at 150-180°C for 30-90 min to form an electron transport layer on the cathode substrate surface.
[0025] More preferably, the SnO2 aqueous solution has a mass fraction of 1% to 4%.
[0026] Further, the preparation of the perovskite light-absorbing layer containing carbonyl and nitrogen organic small molecules in step (2) includes:
[0027] (a) Dissolving a small organic molecule containing carbonyl and nitrogen and a metal halide in a solvent to generate a metal halide precursor solution, wherein the small organic molecule containing carbonyl and nitrogen is N,N-methylenedicarboxamide; the metal halide includes at least one of lead iodide, lead bromide, lead chloride, stannous iodide, stannous bromide, and stannous chloride; and the solvent is a mixed solvent of dimethylformamide and dimethyl sulfoxide.
[0028] (b) Spin-coating the metal halide precursor solution onto the surface of the electron transport layer at 1000–3000 rpm for 30–40 s; followed by annealing at 50–100 °C for 30–120 s.
[0029] (c) Dissolve an organic solute in a solvent, wherein the organic solute includes at least one of formamide iodide, formamide bromide, formamide chloride, methylamine iodide, methylamine bromide, and methylamine chloride, and the solvent is isopropanol; then spin-coat the solution onto the film prepared in step (b) at 2000–5000 rpm for 30–40 s; subsequently, anneal at 150–180 °C for 10–60 min to obtain the organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen.
[0030] More preferably, in step (a), the concentration of the organic small molecules containing carbonyl groups and nitrogen in the metal halide precursor solution is 1-10 mg / mL, and the concentration of the metal halide is 1-1.6 mol / L; the volume ratio of DMF to DMSO is 4:1-9:1.
[0031] More preferably, the metal halide in step (a) is lead iodide.
[0032] More preferably, in step (a), p-toluenesulfonic acid is also added to the metal halide precursor solution, and the concentration of p-toluenesulfonic acid is 0.5 to 3 mg / mL.
[0033] Further, the preparation of the hole transport layer in step (2) includes: dissolving the hole transport layer material powder in chlorobenzene, adding 4-tert-butylpyridine and lithium bis(trifluoromethanesulfonyl)imide, stirring and mixing evenly (stirring overnight), then spin-coating it onto the organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen at 4000-5000 rpm for 30-40 s, and oxidizing it in an atmospheric environment for 8-24 h to obtain the hole transport layer.
[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0035] (1) The method for preparing carbonyl and nitrogen-containing organic small molecule-doped perovskite solar cells provided by this invention involves adding carbonyl and nitrogen-containing organic small molecules to the perovskite precursor solution to adjust the morphology and crystallinity of the PbI2 film, thereby growing PbI2 into a high-quality film with uniformly distributed pores. This provides more ion transport pathways, providing sufficient space for the subsequent growth of the PVK film, which is beneficial for forming a high-quality perovskite film. The addition of carbonyl and nitrogen-containing organic small molecules effectively improves the crystallinity of perovskite, passivates uncoordinated lead ions in the perovskite film, reduces the residue of lead iodide, prolongs the carrier lifetime, and reduces carrier recombination, ultimately improving the photoelectric conversion efficiency of the doped perovskite solar cell; the addition of p-toluenesulfonic acid further improves the photoelectric conversion efficiency of the doped perovskite solar cell.
[0036] (2) This invention can be prepared in the air, is low in cost, environmentally friendly, and can be directly mass-produced, and has a good application prospect.
[0037] (3) The organic small molecule doped perovskite solar cells containing carbonyl and nitrogen prepared by the present invention have high short-circuit current density, high open-circuit voltage, high fill factor and high photoelectric conversion efficiency. Attached Figure Description
[0038] Figure 1 This is a schematic diagram of the structure of the organic small molecule doped perovskite solar cell containing carbonyl and nitrogen groups according to the present invention.
[0039] Figure 2 This is a flowchart illustrating the fabrication method of the perovskite solar cell device containing carbonyl and nitrogen-doped organic small molecules according to the present invention.
[0040] Figure 3 The graph shows the relationship between current density and voltage of the solar cell devices in Example 1 and Comparative Example 1. Detailed Implementation
[0041] The following examples further illustrate specific implementations of the present invention, but the implementation and protection of the present invention are not limited thereto. It should be noted that any processes not specifically described below are those that can be implemented or understood by those skilled in the art by referring to existing technology. Reagents or instruments whose manufacturers are not specified are considered to be conventional products that can be purchased commercially.
[0042] This invention provides an organic small molecule-doped perovskite solar cell containing carbonyl and nitrogen groups, such as... Figure 1 As shown, it includes a cathode substrate, an electron transport layer, a perovskite light-absorbing layer doped with small organic molecules containing carbonyl and nitrogen, a hole transport layer, and an anode electrode.
[0043] The fabrication process of the above-mentioned organic small molecule doped perovskite solar cells containing carbonyl groups and nitrogen is as follows: Figure 2 As shown, it includes the following steps:
[0044] Step 1: Clean the cathode substrate sequentially with detergent, deionized water, acetone, anhydrous ethanol, and isopropanol using ultrasonic cleaning for 15-20 minutes each; then dry it in a vacuum drying oven at 70-90℃.
[0045] Step 2: Perform a surface plasma treatment on the cleaned and dried cathode substrate (ITO) for 10-20 minutes. This treatment method uses the strong oxidizing properties of ozone generated under microwaves to clean residual organic matter on the ITO surface. At the same time, it can increase the oxygen vacancies on the ITO surface and improve the work function of the ITO surface.
[0046] Step 3: Spin-coat SnO2 solution onto the ITO surface treated in Step 2 at 1000-5000 rpm for 30-50 seconds; then anneal at 150-180℃ for 30-90 minutes to form an electron transport layer on the cathode substrate surface.
[0047] Step 4: Spin-coat a metal halide precursor solution onto the surface of the electron transport layer; the metal halide precursor solution is composed of lead iodide and small organic molecules containing carbonyl groups and nitrogen. Spin-coat the precursor solution onto the electron transport layer surface at 1000–3000 rpm for 30–40 s; subsequently, anneal at 50–100°C for 30–120 s.
[0048] Step 5: Dissolve the organic solute in a solvent, and spin-coat the solution onto the film prepared in step 4 at 2000-5000 rpm for 30-40 seconds; then anneal at 150-180°C for 10-60 minutes to obtain the organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen.
[0049] Step 6: Spin-coat a hole transport layer onto the surface of the above-mentioned organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen groups.
[0050] Step 7: Deposit gold (Au) as an anode electrode on the surface of the hole transport layer above, with a thickness of 60-100 nm.
[0051] After the above steps are completed, organic small molecule doped perovskite solar cells containing carbonyl groups and nitrogen are obtained.
[0052] The superior embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0053] Example 1
[0054] The structure of the organic small molecule doped perovskite solar cell device containing carbonyl and nitrogen groups in Example 1 is: ITO / SnO2 / FA. 0.98 MA 0.02 PbI3:C3H6N2O2 / Spiro-OMeTAD / Au.
[0055] The fabrication process of the above perovskite solar cells is as follows:
[0056] Step 1: The cathode substrate is ultrasonically cleaned for 20 minutes each with detergent, deionized water, acetone, anhydrous ethanol, and isopropanol in sequence; then dried in an 80°C drying oven.
[0057] Step 2: Perform a 20-minute surface plasma treatment on the cleaned and dried cathode substrate (ITO). This treatment method utilizes the strong oxidizing properties of ozone generated under microwaves to clean residual organic matter on the ITO surface. At the same time, it can increase the oxygen vacancies on the ITO surface and improve the work function of the ITO surface.
[0058] Step 3: Spin-coat the ITO surface treated in Step 2 with an aqueous SnO2 solution (SnO2 mass fraction of 2.67%) at a speed of 4000 rpm for 30 seconds, and then anneal at 150°C for 60 minutes to form an electron transport layer.
[0059] Step 4: Spin-coat a perovskite active layer onto the surface of the substrate treated above:
[0060] (1) Preparation of metal halide precursor solution: Prepare a 1.5 mol / L PbI2 solution, wherein the solvent is a mixture of DMF and DMSO (the volume ratio of DMF and DMSO is 9:1). Stir at room temperature until completely dissolved, and then add 2 mg N,N-methylenedicarboxamide and 0.5 mg p-toluenesulfonic acid to 1 mL of the solution.
[0061] (2) The metal halide precursor solution is spin-coated on the surface of the electron transport layer at 1500 rpm for 30 s; then, it is annealed at 70°C for 60 s.
[0062] (3) The organic solute was dissolved in a solvent, and the solution was spin-coated onto a lead iodide film at 2000 rpm for 30 s; subsequently, it was annealed at 150 °C for 10 min to obtain the organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen. The solution consisted of 90 mg FAI, 9 mg MACl, and 6.39 mg MAI dissolved in 1 mL of isopropanol.
[0063] Step 5: Spin-coat the hole transport layer solution onto the surface of the above-mentioned organic small molecule-doped perovskite light-absorbing layer containing carbonyl and nitrogen groups at a spin speed of 4000 rpm for 30 seconds; then oxidize overnight under atmospheric conditions. The hole transport layer solution is a mixture of 72.3 mg Spiro-OMeTAD powder dissolved in 1 mL of chlorobenzene, with 29 μL of 4-tert-butylpyridine and 17.5 μL of lithium bis(trifluoromethanesulfonyl)imide (520 mg / mL in acetonitrile) added.
[0064] Step 6: Deposit a gold anode electrode on the surface of the hole transport layer with a thickness of 60 nm.
[0065] After the above steps are completed, an organic small molecule doped perovskite solar cell device containing carbonyl and nitrogen is obtained.
[0066] Comparative Example 1
[0067] The steps of Comparative Example 1 are basically the same as those of Example 1, except that no small organic molecules containing carbonyl and nitrogen are added in step 4, and no toluenesulfonic acid is added. All other parameters are the same as those of Example 1. A perovskite solar cell without carbonyl and nitrogen-containing small organic molecules was prepared in the comparative example.
[0068] Figure 3 This is a graph showing the current density versus voltage relationship between the carbonyl and nitrogen-doped organic small molecule perovskite solar cell of Example 1 and the undoped perovskite solar cell of Comparative Example 1; the dashed line represents the undoped perovskite solar cell of Comparative Example 1 (structure: ITO / SnO2 / FA). 0.98 MA 0.02 The current density versus voltage curves for PbI3 / Spiro-OMeTAD / Au are shown. The solid line represents the carbonyl and nitrogen-doped organic small molecule solar cell of Example 1 (structure: ITO / SnO2 / FA). 0.98 MA 0.02 Current density vs. voltage curves of PbI3:C3H6N2O2 / Spiro-OMeTAD / Au; from Figure 3 It can be seen that the open-circuit voltage (V) of the undoped perovskite solar cell in Comparative Example 1 is... oc The voltage is 1.05V, and the short-circuit current density (J) is... sc The value is 24.02 mA / cm. 2 The fill factor (FF) is 0.6956; the open-circuit voltage (V) of the doped perovskite solar cell in Example 1 is... oc The voltage is 1.13V, and the short-circuit current density (J) is... sc The value is 25.45 mA / cm. 2 The fill factor (FF) is 0.7853. It is evident that the short-circuit current density, open-circuit voltage, and fill factor of the perovskite solar cell device are significantly improved after doping with carbonyl and nitrogen-containing organic small molecules. This indicates that the addition of carbonyl and nitrogen-containing organic small molecules can effectively improve carrier separation and transport efficiency and reduce the defect state density inside the perovskite.
[0069] Comparative Example 2
[0070] The steps of Comparative Example 2 are basically the same as those of Example 1, except that no small organic molecules containing carbonyl groups and nitrogen were added for doping in step 4. All other parameters are the same as those of Example 1. A perovskite solar cell without organic small molecules containing carbonyl groups and nitrogen was prepared in Comparative Example 2.
[0071] Example 2
[0072] The structure of the perovskite solar cell device containing carbonyl and nitrogen-containing organic small molecule doped with carbonyl groups in Example 2 is: ITO / SnO2 / FA.0.98 MA 0.02 PbI3:C3H6N2O2 / Spiro-OMeTAD / Au.
[0073] The fabrication process of the above perovskite solar cells is as follows:
[0074] Step 1: The cathode substrate is ultrasonically cleaned for 20 minutes each with detergent, deionized water, acetone, anhydrous ethanol, and isopropanol in sequence; then dried in an 80°C drying oven.
[0075] Step 2: Perform a 20-minute surface plasma treatment on the cleaned and dried cathode substrate (ITO). This treatment method utilizes the strong oxidizing properties of ozone generated under microwaves to clean residual organic matter on the ITO surface. At the same time, it can increase the oxygen vacancies on the ITO surface and improve the work function of the ITO surface.
[0076] Step 3: Spin-coat the ITO surface treated in Step 2 with an aqueous SnO2 solution (SnO2 mass fraction of 2.67%) at a speed of 4000 rpm for 30 seconds, and then anneal at 150°C for 60 minutes to form an electron transport layer.
[0077] Step 4: Spin-coat a perovskite active layer onto the surface of the substrate treated above:
[0078] (1) Preparation of metal halide precursor solution: Prepare a 1.5 mol / L PbI2 solution, wherein the solvent is a mixture of DMF and DMSO (the volume ratio of DMF and DMSO is 9:1). Stir at room temperature until completely dissolved, and then add 1 mg N,N-methylenedicarboxamide and 0.5 mg p-toluenesulfonic acid to 1 mL of the solution.
[0079] (2) The metal halide precursor solution is spin-coated on the surface of the electron transport layer at 1500 rpm for 30 s; then, it is annealed at 70°C for 60 s.
[0080] (3) The organic solute was dissolved in a solvent, and the solution was spin-coated onto a lead iodide film at 2000 rpm for 30 s; subsequently, it was annealed at 150 °C for 10 min to obtain the organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen. The solution consisted of 90 mg FAI, 9 mg MACl, and 6.39 mg MAI dissolved in 1 mL of isopropanol.
[0081] Step 5: Spin-coat the hole transport layer solution onto the surface of the above-mentioned perovskite organic small molecule doped mineral light-absorbing layer containing carbonyl and nitrogen groups at a spin speed of 4000 rpm for 30 seconds; then oxidize overnight under atmospheric conditions. The hole transport layer solution is a mixed solution of 72.3 mg Spiro-OMeTAD powder dissolved in 1 mL of chlorobenzene, with 29 μL of 4-tert-butylpyridine and 17.5 μL of lithium bis(trifluoromethanesulfonyl)imide (520 mg / mL in acetonitrile) added.
[0082] Step 6: Deposit a gold anode electrode on the surface of the hole transport layer with a thickness of 60 nm.
[0083] After the above steps are completed, an organic small molecule doped perovskite solar cell device containing carbonyl and nitrogen is obtained.
[0084] Example 3
[0085] The structure of the organic small molecule doped perovskite solar cell device containing carbonyl and nitrogen groups in Example 3 is: ITO / SnO2 / FA. 0.98 MA 0.02 PbI3:C3H6N2O2 / Spiro-OMeTAD / Au.
[0086] The fabrication process of the above perovskite solar cells is as follows:
[0087] Step 1: The cathode substrate is ultrasonically cleaned for 20 minutes each with detergent, deionized water, acetone, anhydrous ethanol, and isopropanol in sequence; then dried in an 80°C drying oven.
[0088] Step 2: Perform a 20-minute surface plasma treatment on the cleaned and dried cathode substrate (ITO). This treatment method utilizes the strong oxidizing properties of ozone generated under microwaves to clean residual organic matter on the ITO surface. At the same time, it can increase the oxygen vacancies on the ITO surface and improve the work function of the ITO surface.
[0089] Step 3: Spin-coat the ITO surface treated in Step 2 with an aqueous SnO2 solution (SnO2 mass fraction of 2.67%) at a speed of 4000 rpm for 30 seconds, and then anneal at 150°C for 60 minutes to form an electron transport layer.
[0090] Step 4: Spin-coat a perovskite active layer onto the surface of the substrate treated above:
[0091] (1) Preparation of metal halide precursor solution: Prepare a 1.5 mol / L PbI2 solution, wherein the solvent is a mixture of DMF and DMSO (the volume ratio of DMF and DMSO is 9:1). Stir at room temperature until completely dissolved, and then add 3 mg N,N-methylenedicarboxamide and 0.5 mg p-toluenesulfonic acid to 1 mL of the solution.
[0092] (2) The metal halide precursor solution is spin-coated on the surface of the electron transport layer at 1500 rpm for 30 s; then, it is annealed at 70°C for 60 s.
[0093] (3) The organic solute was dissolved in a solvent, and the solution was spin-coated onto a lead iodide film at 2000 rpm for 30 s; subsequently, it was annealed at 150 °C for 10 min to obtain the organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen. The solution consisted of 90 mg FAI, 9 mg MACl, and 6.39 mg MAI dissolved in 1 mL of isopropanol.
[0094] Step 5: Spin-coat the hole transport layer solution onto the surface of the above-mentioned organic small molecule-doped perovskite light-absorbing layer containing carbonyl and nitrogen groups at a spin speed of 4000 rpm for 30 seconds; then oxidize overnight under atmospheric conditions. The hole transport layer solution is a mixture of 72.3 mg Spiro-OMeTAD powder dissolved in 1 mL of chlorobenzene, with 29 μL of 4-tert-butylpyridine and 17.5 μL of lithium bis(trifluoromethanesulfonyl)imide (520 mg / mL in acetonitrile) added.
[0095] Step 6: Deposit a gold anode electrode on the surface of the hole transport layer with a thickness of 60 nm.
[0096] After the above steps are completed, an organic small molecule doped perovskite solar cell device containing carbonyl and nitrogen is obtained.
[0097] Example 4
[0098] The structure of the perovskite solar cell device containing carbonyl and nitrogen-containing organic small molecule doped with carbonyl groups in Example 4 is: ITO / SnO2 / FA. 0.98 MA 0.02 PbI3:C3H6N2O2 / Spiro-OMeTAD / Au.
[0099] The fabrication process of the above perovskite solar cells is as follows:
[0100] Step 1: The cathode substrate is ultrasonically cleaned for 20 minutes each with detergent, deionized water, acetone, anhydrous ethanol, and isopropanol in sequence; then dried in an 80°C drying oven.
[0101] Step 2: Perform a 20-minute surface plasma treatment on the cleaned and dried cathode substrate (ITO). This treatment method utilizes the strong oxidizing properties of ozone generated under microwaves to clean residual organic matter on the ITO surface. At the same time, it can increase the oxygen vacancies on the ITO surface and improve the work function of the ITO surface.
[0102] Step 3: Spin-coat the ITO surface treated in Step 2 with an aqueous SnO2 solution (SnO2 mass fraction of 2.67%) at a speed of 4000 rpm for 30 seconds, and then anneal at 150°C for 60 minutes to form an electron transport layer.
[0103] Step 4: Spin-coat a perovskite active layer onto the surface of the substrate treated above:
[0104] (1) Preparation of metal halide precursor solution: Prepare a 1.5 mol / L PbI2 solution, wherein the solvent is a mixture of DMF and DMSO (the volume ratio of DMF and DMSO is 9:1). Stir at room temperature until completely dissolved, and then add 5 mg N,N-methylenedicarboxamide and 0.5 mg p-toluenesulfonic acid to 1 mL of the solution.
[0105] (2) The metal halide precursor solution is spin-coated on the surface of the electron transport layer at 1500 rpm for 30 s; then, it is annealed at 70°C for 60 s.
[0106] (3) The organic solute was dissolved in a solvent, and the solution was spin-coated onto a lead iodide film at 2000 rpm for 30 s; subsequently, it was annealed at 150 °C for 10 min to obtain the organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen. The solution consisted of 90 mg FAI, 9 mg MACl, and 6.39 mg MAI dissolved in 1 mL of isopropanol.
[0107] Step 5: Spin-coat the hole transport layer solution onto the surface of the above-mentioned organic small molecule-doped perovskite light-absorbing layer containing carbonyl and nitrogen groups at a spin speed of 4000 rpm for 30 seconds; then oxidize overnight under atmospheric conditions. The hole transport layer solution is a mixture of 72.3 mg Spiro-OMeTAD powder dissolved in 1 mL of chlorobenzene, with 29 μL of 4-tert-butylpyridine and 17.5 μL of lithium bis(trifluoromethanesulfonyl)imide (520 mg / mL in acetonitrile) added.
[0108] Step 6: Deposit a gold anode electrode on the surface of the hole transport layer with a thickness of 60 nm.
[0109] After the above steps are completed, an organic small molecule doped perovskite solar cell device containing carbonyl and nitrogen is obtained.
[0110] Example 5
[0111] Example 5 is basically the same as Example 1 in terms of steps, except that p-toluenesulfonic acid was not added for doping in step 4. All other parameters are the same as in Example 1. Example 5 yields a perovskite solar cell without p-toluenesulfonic acid doping.
[0112] Table 1 compares the parameters of the perovskite solar cell devices prepared in Examples 1-5 and Comparative Examples 1-2.
[0113] Table 1 Comparison of parameters between Examples 1-5 and Comparative Examples 1-2
[0114]
[0115] Table 1 shows that the short-circuit current density (J) in Example 1 is... sc From 24.02 mA / cm 2 Increased to 25.45 mA / cm 2 The fill factor (FF) increased from 0.6956 to 0.7853, and the open-circuit voltage increased from 1.05V to 1.13V. This indicates that the carrier separation and transport efficiency of the perovskite solar cell doped with carbonyl and nitrogen-containing organic small molecules were improved, while its internal defects were effectively suppressed. Its photoelectric conversion efficiency increased from 17.54% to 22.58%. Furthermore, compared to the comparative example, the photoelectric conversion efficiency of the devices in Examples 2-5 all showed varying degrees of improvement.
[0116] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various changes, substitutions, and modifications without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.
Claims
1. A perovskite solar cell doped with carbonyl and nitrogen-containing organic small molecules, characterized in that, From bottom to top, it comprises: a cathode substrate, an electron transport layer, a carbonyl and nitrogen-doped organic small molecule perovskite light-absorbing layer, a hole transport layer, and an anode electrode; the carbonyl and nitrogen-doped organic small molecule is N,N-methylenedicarboxamide; the carbonyl and nitrogen-doped organic small molecule perovskite light-absorbing layer is a perovskite material doped with carbonyl and nitrogen-doped organic small molecules, and the perovskite material has ABX m Y 3-m A perovskite material with a structure in which A is at least one of CH3NH3 and C4H9NH3, B is at least one of Pb and Sn, X and Y are each independently Cl, Br or I, and m is 1, 2 or 3; the mass ratio of the carbonyl and nitrogen-containing organic small molecule to the B-site element is 0.3%-3.5%; The thickness of the organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen is 400–800 nm.
2. The organic small molecule doped perovskite solar cell containing carbonyl and nitrogen groups according to claim 1, characterized in that, The cathode substrate is selected from indium tin oxide glass or fluorine-doped tin oxide glass; The electron transport layer is a TiO2 or SnO2 thin film; the thickness of the electron transport layer is 30-50 nm. The hole transport layer is at least one of NiO, CuO, CuSCN, CuI, tungsten trioxide, molybdenum trioxide, vanadium pentoxide, Spiro-OMeTAD, P3HT, PTAA, NPB, and TPD; the thickness of the hole transport layer is 30–100 nm. The anode electrode is made of Au and has a thickness of 600~1000 Å.
3. The method for preparing the organic small molecule doped perovskite solar cell containing carbonyl and nitrogen according to any one of claims 1 to 2, characterized in that, Includes the following steps: (1) Clean the cathode substrate and then perform surface treatment on the cathode substrate to obtain a surface-treated cathode surface; (2) On the cathode surface after surface treatment in step (1), an electron transport layer, an organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen and a hole transport layer are sequentially spin-coated. (3) An anode electrode is deposited on the surface of the hole transport layer described in step (2) to obtain the organic small molecule doped perovskite solar cell containing carbonyl and nitrogen.
4. The method for preparing a carbonyl- and nitrogen-containing organic small molecule-doped perovskite solar cell according to claim 3, characterized in that, In step (1), the cathode substrate treatment includes: firstly, ultrasonically cleaning the cathode substrate with detergent, deionized water, acetone, anhydrous ethanol and isopropanol for 15-20 minutes each; then drying it in a vacuum drying oven at 70-90℃; and finally performing plasma surface treatment on the cleaned and dried cathode substrate surface for 10-20 minutes.
5. The method for preparing a carbonyl- and nitrogen-containing organic small molecule-doped perovskite solar cell according to claim 3, characterized in that, The preparation of the electron transport layer in step (2) includes: spin-coating an aqueous SnO2 solution onto the surface of the surface-treated cathode substrate at 1000-5000 rpm for 30-50 s; then annealing at 150-180°C for 30-90 min to form an electron transport layer on the cathode substrate surface.
6. The method for preparing a carbonyl- and nitrogen-containing organic small molecule-doped perovskite solar cell according to claim 3, characterized in that, Step (2) involves the preparation of the organic small molecule-doped perovskite light-absorbing layer containing carbonyl and nitrogen groups, which includes: (a) Dissolving a small organic molecule containing carbonyl and nitrogen and a metal halide in a solvent to generate a metal halide precursor solution, wherein the small organic molecule containing carbonyl and nitrogen is N,N-methylenedicarboxamide; the metal halide includes at least one of lead iodide, lead bromide, lead chloride, stannous iodide, stannous bromide, and stannous chloride; and the solvent is a mixed solvent of dimethylformamide and dimethyl sulfoxide. (b) Spin-coating the metal halide precursor solution onto the surface of the electron transport layer at 1000–3000 rpm for 30–40 s; followed by annealing at 50–100 °C for 30–120 s. (c) Dissolve an organic solute in a solvent, wherein the organic solute includes at least one of formamide iodide, formamide bromide, formamide chloride, methylamine iodide, methylamine bromide, and methylamine chloride, and the solvent is isopropanol; then spin-coat the solution onto the film prepared in step (b) at 2000–5000 rpm for 30–40 s; subsequently, anneal at 150–180 °C for 10–60 min to obtain the organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen.
7. The method for preparing a carbonyl- and nitrogen-containing organic small molecule-doped perovskite solar cell according to claim 6, characterized in that, In step (a), the concentration of small organic molecules containing carbonyl groups and nitrogen in the metal halide precursor solution is 1–10 mg / mL, and the concentration of metal halide is 1–1.6 mol / L; In step (a), p-toluenesulfonic acid is also added to the metal halide precursor solution, with a concentration of 0.5–3 mg / mL.
8. The method for preparing a carbonyl- and nitrogen-containing organic small molecule-doped perovskite solar cell according to claim 3, characterized in that, The preparation of the hole transport layer in step (2) includes: dissolving the hole transport layer material powder in chlorobenzene, adding 4-tert-butylpyridine and lithium bis(trifluoromethanesulfonyl)imide, stirring and mixing evenly, then spin-coating it onto the organic small molecule doped perovskite light-absorbing layer containing carbonyl and nitrogen at 4000-5000 rpm for 30-40 s, and oxidizing it in an atmospheric environment for 8-24 h to obtain the hole transport layer.