A pyrene derivative-doped perovskite photosensitive layer, its preparation method and application

Abstract

This application belongs to the technical field of perovskite photosensitive layers for solar cells, and discloses a pyrene derivative-doped perovskite photosensitive layer, its preparation method, and its application. The pyrene derivative-doped perovskite photosensitive layer described in this application is prepared by spin-coating and annealing a perovskite precursor solution doped with 1-pyrenecarboxaldehyde. The 1-pyrenecarboxaldehyde doping provided in this application can passivate insufficiently coordinated lead ions (Pb). 2+ By eliminating defects, reducing the defect state density of the perovskite photosensitive layer, and forming a high-quality perovskite thin film, the 1-pyrene-formaldehyde-doped perovskite solar cells prepared significantly improve the light conversion efficiency, enhance the stability of the perovskite solar cell device, extend the effective working time of the solar cell, and effectively prevent pollution to the surrounding environment caused by lead leakage.

Description

Technical Field

[0001] This application relates to perovskite photosensitive layers for solar cells, and particularly to a perovskite photosensitive layer doped with pyrene derivatives, its preparation method, and its application. Background Technology

[0002] Organic-inorganic hybrid metal halide perovskite solar cells (PSCs) have become one of the most promising photovoltaic technologies due to their simple manufacturing process and excellent photovoltaic performance. This is mainly because of the superior photoelectric properties of perovskite materials, such as high light absorption coefficient, low trap density, long carrier lifetime, high carrier mobility, and low exciton binding energy. In the past decade, the photoelectric conversion efficiency of organic-inorganic hybrid perovskite solar cells has significantly improved, from the initial 3.8% to the current 26.1%, demonstrating great potential as high-efficiency photovoltaic devices.

[0003] Numerous defects are generated on the surface of perovskite thin films during fabrication and exposure to air, and these defects are key limiting factors for the performance of perovskite solar cells. Currently, the main component of perovskite solar cells is organic-inorganic hybrid perovskite. High-performance perovskite solar cells often contain the heavy metal lead, including undercoordinated Pb. 2+ Ions can cause nonradiative recombination at the perovskite-charge transport layer interface, limiting photovoltage and fill factor, resulting in low photoconversion efficiency. Simultaneously, defects can allow moisture or oxygen to penetrate the perovskite film, accelerating perovskite decomposition and leading to instability in perovskite solar cell devices. Lead, as a heavy metal, can pollute the surrounding environment if leaked. Therefore, efficient passivation of uncoordinated Pb is crucial. 2+ Effectively managing lead leaks is currently one of the research focuses. Summary of the Invention

[0004] To address the undercoordination of Pb in existing technologies 2+ To address the technical problems such as low light conversion efficiency, poor stability, and pollution caused by lead leakage, this application provides a pyrene derivative-doped perovskite photosensitive layer, its preparation method, and its application.

[0005] To solve the above-mentioned technical problems, this application adopts the following technical solution:

[0006] A perovskite photosensitive layer doped with pyrene derivatives, wherein the perovskite photosensitive layer is prepared by spin-coating and annealing a perovskite precursor solution doped with 1-pyrenecarboxaldehyde.

[0007] Furthermore, the thickness of the perovskite photosensitive layer described in this application is 600–900 nm.

[0008] Secondly, this application also provides a method for preparing a perovskite photosensitive layer, comprising the following steps: adding PbI2 (lead iodide), FAI (formamidine iodide), PbBr2 (lead bromide), MACl (chloromethylamine), CsI (cesium iodide), FABr (formamidine bromo), and MAI (formamidine iodide) in a mass ratio to a mixed solvent of DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide) to obtain a perovskite precursor solution; adding a 1-pyrene formaldehyde (Py-CHO) solution to the perovskite precursor solution to obtain a perovskite precursor mixture; spin-coating the perovskite precursor mixture onto an electron transport layer; and annealing to form a 1-pyrene formaldehyde-doped perovskite photosensitive layer.

[0009] Furthermore, the mass ratio of PbI2, FAI, PbBr2, MACl, CsI, FABr, and MAI is 92.38:29.7:6.19:5:3.84:2.13:1, and the volume ratio of the solvents DMF and DMSO is 4:1.

[0010] Furthermore, the concentration of the 1-pyrene formaldehyde solution added is 0.1–1 mg / mL.

[0011] Furthermore, the spin-coating conditions include: statically dropping the precursor solution onto the electron transport layer, spin-coating at 1000 rpm for 10 seconds, then spin-coating at 3000 rpm for 30 seconds; adding 0.3 mL of ethyl acetate as an antisolvent 20 seconds before the spin-coating is complete; and annealing at 100°C for 40 minutes after spin-coating to obtain the perovskite photosensitive layer FA. 0.90 MA 0.03 Cs 0.07 Pb(I 0.92 Br 0.08 3.

[0012] Finally, this application also provides the application of a pyrene derivative-doped perovskite photosensitive layer, which is applied to a perovskite solar cell. The perovskite solar cell includes a conductive substrate, an electron transport layer, and the aforementioned pyrene derivative-doped perovskite photosensitive layer, hole transport layer, and top electrode.

[0013] Furthermore, the conductive substrate is an FTO or ITO conductive substrate, the electron transport layer is a SnO2 layer, and the top electrode is a highly conductive metal electrode or a highly conductive carbon material electrode.

[0014] Furthermore, the SnO2 layer has a thickness of 30–50 nm.

[0015] Furthermore, the method for preparing the hole transport layer includes the following steps:

[0016] Phenethyl ammonium bromide was dissolved in isopropanol as a passivating agent, and the passivating agent was coated onto the perovskite photosensitive layer by spin coating.

[0017] A solution of lithium bis(trifluoromethanesulfonyl)imide, 4-tert-butylpyridine, and a solution of cobalt bis(trifluoromethanesulfonyl)imide were added to a chlorobenzene solution of Spiro-OMeTAD (2,2',7,7'-tetra-(dimethoxydiphenylamine)-spirofluorene) and stirred until homogeneous to obtain a mixture.

[0018] The mixture is coated onto a perovskite photosensitive layer coated with the passivating agent using a spin-coating method to obtain the hole transport layer.

[0019] More specifically, the method for preparing the hole transport layer includes the following steps:

[0020] Weigh out PEAI (phenylethyl ammonium bromide), dissolve it in IPA (isopropanol) as a passivating agent; take out the passivating agent and apply it to the perovskite photosensitive layer by spin coating. Start spin coating when the spin coating speed is 4000 rpm and finish after 20 seconds.

[0021] Weigh Spiro-OMeTAD (2,2',7,7'-tetra-(dimethoxydiphenylamine)-spirofluorene), add a magnetic stir bar, add Spiro-OMeTAD to chlorobenzene, stir and mix evenly to obtain a Spiro-OMeTAD solution with a mass concentration of 72.25 mg / mL;

[0022] The Li-TFSI (lithium bis(trifluoromethanesulfonyl)imide) solution, 4-tert-butylpyridine (TBP) and CO-TFSI (cobalt bis(trifluoromethanesulfonyl)imide) solution were measured and added to the Spiro-OMeTAD solution obtained in the previous step. The mixture was stirred and mixed evenly to obtain mixture A.

[0023] The mixture A obtained in the previous step is statically coated onto the perovskite photosensitive layer using a spin coating method. The spin coating speed is 4000 rpm and the time is 30 s to obtain the hole transport layer.

[0024] This application provides a perovskite photosensitive layer doped with pyrene derivatives, prepared by spin-coating and annealing a perovskite precursor solution doped with 1-pyrenecarboxaldehyde. The 1-pyrenecarboxaldehyde derivative is doped into the perovskite photosensitive layer, and the carbonyl functional group in 1-pyrenecarboxaldehyde can passivate insufficiently coordinated lead ions (Pb). 2+ The carbonyl C=O bond has a defect where the electron cloud distribution is biased towards the oxygen atom, which determines the strong polarity and active chemical reactivity of the carbonyl group. The lone pair of electrons on the carbonyl oxygen can interact with unpaired Pb atoms on the perovskite surface. 2+ The ions undergo Lewis acid-base reactions, passivating the unpaired Pb. 2+The presence of ions can reduce the defect state density of the perovskite photosensitive layer and form a high-quality perovskite film. 1-Pyrene carbaldehyde can significantly reduce defect states, effectively suppress carrier recombination, and effectively suppress uncoordinated Pb. 2+ Migration within the perovskite layer significantly improves photovoltage and fill factor, thereby enhancing light conversion efficiency. The reduction of defect states by 1-pyrenecarboxaldehyde also prevents moisture or oxygen from penetrating into the perovskite film, improving the stability of perovskite solar cell devices and greatly extending the effective operating time of solar cells. Simultaneously, unpaired Pb... 2+ The ions form a complex with 1-pyrene formaldehyde, which can effectively prevent pollution to the surrounding environment caused by lead leakage. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the perovskite solar cell structure provided in this application;

[0026] Figure 2 Performance comparison diagram of perovskite solar cells prepared with perovskite photosensitive layers provided in Examples 1, 2, 3, Comparative Examples 1, 2, and 3;

[0027] Figure 3 The graph shows a performance comparison of the perovskite solar cell prepared by the 1-pyrene-formaldehyde-doped perovskite photosensitive layer provided in Example 1 after 3 hours and 170 hours of storage. Detailed Implementation

[0028] This application discloses a pyrene derivative-doped perovskite photosensitive layer, its preparation method, and its applications. Those skilled in the art can refer to the content of this application and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this application. The methods and applications of this application have been described through preferred embodiments. Those skilled in the art can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this application to realize and apply the technology of this application.

[0029] To enable those skilled in the art to better understand this application, the following detailed description is provided in conjunction with specific embodiments.

[0030] Example 1: Preparation of a perovskite photosensitive layer doped with pyrene derivatives

[0031] PbI2, FAI, PbBr2, MACl, CsI, FABr, and MAI were added to a mixed solvent of DMF and DMSO in a volume ratio of 4:1 at a mass ratio of 92.38:29.7:6.19:5:3.84:2.13:1. A 1-pyrene formaldehyde solution with a concentration of 0.5 mg / mL was added, and the mixture was stirred until homogeneous to obtain a precursor mixture. The resulting mixture was spin-coated onto the electron transport layer SnO2. The precursor mixture was statically added dropwise and then spin-coated at 1000 rpm for 10 s, followed by spin-coating at 3000 rpm for 30 s. 20 s before the spin-coating was completed, 0.3 mL of anisole was added as an antisolvent. After spin-coating, the mixture was annealed at 100 °C for 40 min to obtain a 1-pyrene formaldehyde-doped perovskite photosensitive layer.

[0032] Example 2: Preparation of a perovskite photosensitive layer doped with pyrene derivatives

[0033] PbI2, FAI, PbBr2, MACl, CsI, FABr, and MAI were added to a mixed solvent of DMF and DMSO in a volume ratio of 4:1 at a mass ratio of 92.38:29.7:6.19:5:3.84:2.13:1. A 1-pyrene formaldehyde solution with a concentration of 0.1 mg / mL was added, and the mixture was stirred until homogeneous to obtain a precursor mixture. The resulting mixture was spin-coated onto the electron transport layer SnO2. The precursor mixture was statically added dropwise and then spin-coated at 1000 rpm for 10 s, followed by spin-coating at 3000 rpm for 30 s. 20 s before the spin-coating was completed, 0.3 mL of anisole was added as an antisolvent. After spin-coating, the mixture was annealed at 100 °C for 40 min to obtain a 1-pyrene formaldehyde-doped perovskite photosensitive layer.

[0034] Example 3: Preparation of a perovskite photosensitive layer doped with pyrene derivatives

[0035] PbI2, FAI, PbBr2, MACl, CsI, FABr, and MAI were added to a mixed solvent of DMF and DMSO in a volume ratio of 4:1 at a mass ratio of 92.38:29.7:6.19:5:3.84:2.13:1. A 1-pyrene formaldehyde solution with a concentration of 1 mg / mL was added, and the mixture was stirred until homogeneous to obtain a precursor mixture. The resulting mixture was spin-coated onto the electron transport layer SnO2. The precursor mixture was statically added dropwise and spin-coated at 1000 rpm for 10 s, then at 3000 rpm for 30 s. 20 s before the spin-coating was completed, 0.3 mL of anisole was added as an antisolvent. After spin-coating, the mixture was annealed at 100 °C for 40 min to obtain a 1-pyrene formaldehyde-doped perovskite photosensitive layer.

[0036] Example 4: Fabrication of Perovskite Solar Cells

[0037] Step 1: Clean the FTO conductive substrate sequentially with detergent, cleaning solution, water, deionized water, acetone, and anhydrous ethanol using ultrasonic cleaning for 30 minutes, then blow dry.

[0038] Step 2: The conductive substrate treated in Step 1 is then treated with ultraviolet ozone for 30 minutes.

[0039] Step 3: Form a SnO2 layer on the conductive substrate obtained in Step 2 to obtain an electron transport layer.

[0040] The electron transport SnO2 layer can preferably be prepared according to the following method:

[0041] 400 μl of the sonicated tin dioxide solution was mixed with a 1:4 deionized water solution and sonicated for 5 min to ensure thorough mixing. The mixture was then filtered using a pipette tip. 70 μl of the tin dioxide solution was statically added dropwise to the substrate using a pipette and spin-coated at 3000 rpm. After spin-coating, the substrate was annealed at 150 °C for 30 min and then subjected to UV ozone treatment for 10 min to form an electron transport SnO2 layer.

[0042] Step 4: Prepare a 1-pyrene-carboxaldehyde-doped perovskite photosensitive layer according to the method of preparing the perovskite photosensitive layer in Example 1 of this application;

[0043] Step 5: Prepare a hole transport layer on the perovskite photosensitive layer;

[0044] The hole transport layer can preferably be prepared according to the following steps:

[0045] 5.1 Weigh 50 mg of PEAI (phenylethyl ammonium bromide) and dissolve it in 1 mL of IPA (isopropanol) as a passivating agent; take 60 μL of the above passivating agent and apply it to the perovskite photosensitive layer by spin coating. Start spin coating when the spin coating speed is 4000 rpm and finish after 20 seconds.

[0046] 5.2 Weigh 72.25 mg Spiro-OMeTAD (2,2',7,7'-tetra-(dimethoxydiphenylamine)-spirofluorene) and add it to a magnetic stir bar; add Spiro-OMeTAD to chlorobenzene and stir to mix evenly to obtain a Spiro-OMeTAD solution with a mass concentration of 72.25 mg / mL;

[0047] 5.3 Take 17.5 μL of Li-TFSI (lithium bis(trifluoromethanesulfonyl)imide) solution, 29 μL of 4-tert-butylpyridine (TBP), and 10 μL of CO-TFSI (cobalt bis(trifluoromethanesulfonyl)imide) solution and add them to 1 mL of Spiro-OMeTAD solution obtained in step 5.2. Stir and mix thoroughly to obtain mixture A.

[0048] 5.4 The mixture A obtained in step 5.3 is statically coated onto the perovskite photosensitive layer by spin coating at a speed of 4000 rpm for 30 s to obtain the hole transport layer.

[0049] Step 6: Fabricate a metal electrode on the hole transport layer: Prepare an 800nm ​​silver electrode on the hole transport layer obtained in step 5 using a vapor deposition method to obtain the perovskite solar cell.

[0050] Comparative Example 1: Preparation of Undoped Perovskite Photosensitive Layer

[0051] PbI2, FAI, PbBr2, MACl, CsI, FABr, and MAI were added to a mixed solvent of DMF and DMSO in a volume ratio of 4:1 at a mass ratio of 92.38:29.7:6.19:5:3.84:2.13:1 and stirred until homogeneous to obtain a precursor solution. The precursor solution was then spin-coated onto the electron transport layer SnO2. The precursor mixture was statically added dropwise and then spin-coated at 1000 rpm for 10 s, followed by spin-coating at 3000 rpm for 30 s. 20 s before the spin-coating was completed, 0.3 mL of anisole was added as an anti-solvent. After spin-coating, the mixture was annealed at 100 °C for 40 min to obtain the perovskite photosensitive layer.

[0052] Comparative Example 2: Preparation of 4-biphenylaldehyde-doped perovskite photosensitive layer

[0053] PbI2, FAI, PbBr2, MACl, CsI, FABr, and MAI were added to a mixed solvent of DMF and DMSO in a volume ratio of 4:1 at a mass ratio of 92.38:29.7:6.19:5:3.84:2.13:1. A 0.5 mg / mL solution of 4-biphenylaldehyde was added, and the mixture was stirred until homogeneous to obtain a precursor mixture. The resulting mixture was spin-coated onto the electron transport layer SnO2. The precursor mixture was statically added dropwise and then spin-coated at 1000 rpm for 10 s, followed by spin-coating at 3000 rpm for 30 s. 20 s before the spin-coating was completed, 0.3 mL of anisole was added as an antisolvent. After spin-coating, the mixture was annealed at 100 °C for 40 min to obtain a 4-biphenylaldehyde-doped perovskite photosensitive layer.

[0054] Comparative Example 3: Preparation of 2-naphthaldehyde-doped perovskite photosensitive layer

[0055] PbI2, FAI, PbBr2, MACl, CsI, FABr, and MAI were added to a mixed solvent of DMF and DMSO in a volume ratio of 4:1 at a mass ratio of 92.38:29.7:6.19:5:3.84:2.13:1. A 0.5 mg / mL solution of 2-naphthaldehyde was added, and the mixture was stirred until homogeneous to obtain a precursor mixture. The resulting mixture was spin-coated onto the electron transport layer SnO2. The precursor mixture was statically added dropwise and then spin-coated at 1000 rpm for 10 s, followed by spin-coating at 3000 rpm for 30 s. 20 s before the spin-coating was completed, 0.3 mL of anisole was added as an antisolvent. After spin-coating, the mixture was annealed at 100 °C for 40 min to obtain a 2-naphthaldehyde-doped perovskite photosensitive layer.

[0056] Example 1

[0057] The solar cells prepared using the same method as in Example 4, namely the 1-pyrene-formaldehyde-doped perovskite photosensitive layer prepared in Examples 1, 2, and 3, the perovskite photosensitive layer prepared in Comparative Example 1, the 4-biphenylformaldehyde-doped perovskite photosensitive layer prepared in Comparative Example 2, and the 2-naphthaldehyde-doped perovskite photosensitive layer prepared in Comparative Example 3, were tested for photoelectric performance under standard sunlight.

[0058] 1.1 Stability testing of perovskite solar cells prepared in Example 1 and Comparative Example 1 after one week of storage. The perovskite layer of the solar cell prepared without 1-pyrene formaldehyde doping (Comparative Example 1) showed significant degradation; the perovskite photosensitive layer prepared in Comparative Example 2 with 4-biphenylformaldehyde doping and the perovskite photosensitive layer prepared in Comparative Example 3 with 2-naphthaldehyde doping had begun to show degradation; while the perovskite layer of the solar cell prepared with 1-pyrene formaldehyde doping (Example 1) showed almost no degradation. The 1-pyrene formaldehyde doping perovskite photosensitive layer prepared in Example 1 can significantly improve the overall air stability of the perovskite solar cell device.

[0059] 1.2 The perovskite photosensitive layers prepared in Examples 1, 2, 3, Comparative Examples 1, 2, and 3 were used to prepare perovskite solar cells using the same method as in Example 4. The photoelectric conversion efficiency was tested, and the test results are as follows.

[0060] Table 1. Open-circuit voltage, short-circuit current density, fill factor, and photoelectric conversion efficiency data for different examples.

[0061]

[0062] Figure 2The results show that the efficiency of the 1-pyrenecarboxaldehyde-doped perovskite solar cell is significantly improved compared with that of the undoped perovskite solar cell, with higher open-circuit voltage (Voc), shorter-circuit current density (Jsc), and fill factor (FF). Table 1 shows that compared with Comparative Example 1 (without passivation agent), the photoelectric conversion efficiency of the 1-pyrenecarboxaldehyde-doped perovskite solar cell increased from 20.19% to 23.21%, an increase of 3.02%. Compared with Comparative Examples 2 and 3 (with passivation agents 4-biphenylcarboxaldehyde and 2-naphthaldehyde), the photoelectric conversion efficiency of the 1-pyrenecarboxaldehyde-doped perovskite solar cell increased by 1.41% and 1.8%, respectively. Therefore, the perovskite solar cell device prepared with the 1-pyrenecarboxaldehyde-doped perovskite photosensitive layer provided in this application has a relatively high photoelectric conversion efficiency.

[0063] Figure 3 The results showed that the voltage and current density of the 1-pyrenecarboxylate-doped perovskite solar cells did not significantly decrease after 3 hours and 170 hours of storage. Therefore, the 1-pyrenecarboxylate-doped solar cells exhibit enhanced operational stability and extended their effective operating time. Furthermore, the performance of the 1-pyrenecarboxylate-doped perovskite solar cell devices reached its optimal level after adding a 0.5 mg / mL 1-pyrenecarboxylate solution.

[0064] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A pyrene derivative doped lead-based perovskite photoactive layer, characterized in that: The perovskite photoactive layer is prepared by spin-coating and annealing of a perovskite precursor solution doped with 1-pyrene carboxaldehyde.

2. The lead-based perovskite photoactive layer of claim 1, wherein: The thickness of the perovskite photoactive layer is 600-900 nm.

3. The method for preparing the lead-based perovskite photosensitive layer as described in claim 1, characterized in that: PbI2, FAI, PbBr2, MACl, CsI, FABr and MAI are added into a mixed solvent of DMF and DMSO according to a mass ratio to obtain a perovskite precursor solution, a 1-pyrene carboxaldehyde solution is added into the perovskite precursor solution to obtain a perovskite precursor mixture, the perovskite precursor mixture is spin-coated onto an electron transport layer, and annealing is performed to prepare a 1-pyrene carboxaldehyde-doped perovskite photoactive layer.

4. The method of producing a lead-based perovskite photoactive layer according to claim 3, characterized in that: The mass ratio of PbI2, FAI, PbBr2, MACl, CsI, FABr and MAI is 92.38:29.7:6.19:5:3.84:2.13:1, and the volume ratio of the solvents DMF and DMSO is 4:

1.

5. The method of producing a lead-based perovskite photoactive layer according to claim 3 or 4, characterized in that: The addition concentration of the 1-pyrene carboxaldehyde solution is 0.1-1 mg / mL.

6. The method of producing a lead-based perovskite photoactive layer according to claim 3 or 4, characterized in that: The spin coating conditions include that the precursor mixed solution is spin coated at a rotation speed of 1000 rpm for 10 s and then at a rotation speed of 3000 rpm for 30 s on the electron transport layer, 0.3 mL of ethyl acetate is added as an anti-solvent 20 s before the completion of the spin coating, and the perovskite light-sensitive layer FA is obtained after annealing at 100 ℃ for 40 min. 0.90 MA 0.03 Cs 0.07 Pb(I 0.92 Br 0.08 )3.

7. A perovskite solar cell, characterized by: The device comprises a conductive substrate, an electron transport layer, a lead-based perovskite photoactive layer according to any one of claims 1-2, a hole transport layer and a top electrode.

8. The perovskite solar cell of claim 7, wherein: The conductive substrate is an FTO or ITO conductive substrate, the electron transport layer is a SnO2 layer, and the top electrode is a highly conductive metal electrode or a highly conductive carbon material electrode.

9. The perovskite solar cell of claim 8, wherein: The thickness of the SnO2 layer is 30-50 nm.

10. The perovskite solar cell according to claim 7 or 8, wherein: The preparation method of the hole transport layer comprises, phenethylammonium bromide is dissolved in isopropyl alcohol as a passivation agent, and the passivation agent is coated onto the perovskite photoactive layer by spin coating; a lithium bis-trifluoromethylsulfonylimide solution, 4-tert-butylpyridine and a cobalt bis-trifluoromethylsulfonylimide solution are added into a chlorobenzene solution of Spiro-OMeTAD, and the mixture is stirred and mixed uniformly to obtain a mixed solution; the mixed solution is coated onto the perovskite photoactive layer coated with the passivation agent by spin coating to obtain the hole transport layer.

Images