Perovskite battery based on pyrrolidone derivative modification and preparation method thereof

Abstract

The invention belongs to the technical field of semiconductor devices, and discloses a perovskite battery based on pyrrolidone derivative modification and a preparation method thereof. The perovskite cell based on pyrrolidone derivative modification comprises a conductive glass substrate, a hole transport layer, a perovskite layer, an electron transport layer and an electrode from bottom to top. Wherein the material of the perovskite layer is perovskite doped with a pyrrolidone derivative, and the molar ratio of the pyrrolidone derivative to the perovskite is 1: 143. According to the preparation method, a blade coating method is adopted to prepare a perovskite thin film, a pyrrolidone derivative is dissolved in N, N-dimethylformamide to obtain an additive solution, then the additive solution is mixed with a perovskite precursor solution, and the mixture is blade-coated on the surface of a hole transport layer to obtain a modified perovskite layer, so that the perovskite thin film can be prepared under the condition that no new technology is added. The perovskite thin film bottom-buried interface hole is significantly inhibited, the stability and the photoelectric conversion efficiency of the perovskite solar cell are improved, and the effective illumination area of the device for efficiency measurement is 4 cm < 2 >.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology, relates to the repair of the buried interface in perovskite cells, and specifically relates to a perovskite cell modified with pyrrolidone derivatives and a preparation method thereof. Background Art

[0002] The inverted perovskite solar cell includes a hole transport layer, a perovskite layer, an electron transport layer, and an electrode from bottom to top. When the perovskite layer is spin-coated or blade-coated on the surface of the hole transport layer, some high-boiling solvents in the perovskite precursor solution cannot be volatilized at one time during the annealing process of the perovskite film, resulting in nano-pores at the buried interface where the perovskite film contacts the hole transport layer. These nano-pores not only affect the conversion efficiency of the cell but also are not conducive to the long-term stable operation of the cell.

[0003] In order to reduce the nano-pores on the buried interface, the prior art introduces additional preparation processes or adds expensive modification additives, which will lead to an increase in production costs and is a disadvantage for the commercialization of perovskite cells. Therefore, there is an urgent need for a simple and low-cost method for preparing high-quality perovskite films. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a perovskite cell modified with pyrrolidone derivatives and a preparation method thereof. Pyrrolidone derivatives are introduced as multifunctional additives, and through their strong coordination with perovskite, they partially replace the complexation of high-boiling solvents in the perovskite precursor with perovskite, reduce the pores caused by incomplete solvent volatilization, optimize the crystallization kinetics process, obtain a dense perovskite film, effectively inhibit the density of defect states, and improve the efficiency of perovskite devices.

[0005] A perovskite cell modified with pyrrolidone derivatives includes a conductive glass substrate, a hole transport layer, a perovskite layer, an electron transport layer, and an electrode from bottom to top. The material of the perovskite layer is perovskite doped with pyrrolidone derivatives, and the molar ratio of the pyrrolidone derivative to perovskite is 1:143.

[0006] Preferably, the pyrrolidone derivative is one or more of oxiracetam, piracetam, and aniracetam.

[0007] Preferably, the perovskite is (FA 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.9 Br 0.1 ) 3 .

[0008] Preferably, the hole transport layer material is MeO-2PacZ or 2PacZ, with a thickness of 80 - 130 μm. The thickness of the perovskite layer is 500 - 800 nm. The electron transport layer material is PC 61 BM or C 60 , with a thickness of 20 - 30 nm. The electrode material is Cu or Ag, with a thickness of 80 - 130 nm.

[0009] A preparation method of a perovskite battery modified with pyrrolidone derivatives specifically includes the following steps:

[0010] Step 1: Dissolve the pyrrolidone derivative in N,N-dimethylformamide to prepare an additive solution with a concentration of 1 mg / ml.

[0011] Step 2: Add the additive solution obtained in Step 1 to a perovskite precursor solution with a concentration of 1.2 mol / ml according to a volume ratio of 1:100, and stir well for 1 h.

[0012] Step 3: Prepare a Meo-2PACz solution with a concentration of 1.0 mg / ml. Under a nitrogen environment at a temperature of 18 - 25 °C, scrape the Meo-2PACz solution onto the surface of the conductive glass substrate. Set the blade height to 30 - 130 μm, the plate speed to 3 - 6 mm / s, heat the substrate at 20 - 25 °C, set the nitrogen air knife to 9 - 12 kPa, and finally anneal at 90 - 110 °C for 10 - 15 mins to obtain the hole transport layer.

[0013] Step 4: Scrape the perovskite precursor solution mixed with the additive solution in Step 2 onto the surface of the hole transport layer. Under a nitrogen environment, set the gap to 100 μm, the coating speed to 2 mm / s, the hot plate temperature to 60 °C, the air knife at 120 L / min, an incident angle of 90°, and a top blowing distance of 50 mm. Then irradiate under an IR lamp at 60 °C for 1 minute, and subsequently anneal at 130 °C for 1 hour to obtain the pyrrolidone derivative-modified perovskite layer.

[0014] Step 5: Evaporate C 60 and BCP in sequence on the surface of the pyrrolidone derivative-modified perovskite layer to obtain the electron transport layer.

[0015] Step 6: Evaporate an Ag electrode with a thickness of 200 nm on the surface of the electron transport layer to obtain the perovskite solar cell modified with pyrrolidone derivatives.

[0016] The present invention has the following beneficial effects:

[0017] By adding pyrrolidone derivatives as additives to the perovskite precursor solution, the crystallization kinetics process can be optimized without adding additional processes, obtaining a dense perovskite film, efficiently and greenly repairing the nano-pores at the perovskite bottom interface. The density of defect states can be effectively inhibited, the stability of perovskite devices can be improved, the carrier transport efficiency can be enhanced, and the conversion efficiency of perovskite solar cells can be significantly increased. Description of the Drawings

[0018] Figure 1 SEM image of the bottom interface of the perovskite solar cell prepared in Comparative Example 1;

[0019] Figure 2 SEM image of the cross-section of the perovskite solar cell prepared in Comparative Example 1;

[0020] Figure 3 SEM image of the bottom interface of the perovskite solar cell prepared in Example 3;

[0021] Figure 4 SEM image of the cross-section of the perovskite solar cell prepared in Example 3. Detailed Description of the Invention

[0022] Comparative Example 1

[0023] A conventional perovskite solar cell was prepared in this comparative example, and the specific steps are as follows:

[0024] Step 1: The conductive glass substrate was ultrasonically cleaned successively with a cleaner, deionized water, ethanol, and isopropanol.

[0025] Step 2: A Meo-2PACz solution with a concentration of 1.0 mg / ml was prepared. Under a nitrogen environment at a temperature of 18 - 25 °C, the hole transport layer was spin-coated on the surface of the conductive glass substrate. The height of the spin-coater blade was set to 50 μm, the plate speed was set to 5 mm / s, the substrate was heated at 25 °C, and the nitrogen air knife was at 10 kPa. After spin-coating, it was annealed on a hot plate at 100 °C for 15 minutes to complete the preparation of the hole transport layer.

[0026] Step 3: A perovskite precursor solution with a concentration of 1.2 mol / ml (FA 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.9 Br 0.1 ) 3, set the blade gap of the doctor blade coater to 100 μm, the coating speed to 2 mm / s, the hot plate temperature to 60 °C, blow nitrogen with an air knife at 120 L / min, the incident angle to 90 °, the top blowing distance to 50 mm, scrape the perovskite precursor solution on the surface of the hole transport layer to obtain a perovskite thin film, then irradiate it under an IR lamp at 60 °C for 1 minute, and then anneal it on a hot stage at 130 °C for 1 hour to complete the preparation of the perovskite layer.

[0027] Step Four: At a speed of , deposit C with a thickness of 27 nm and BCP with a thickness of 8 nm on the surface of the perovskite layer in sequence to complete the preparation of the electron transport layer. 60

[0028] Step Five: Deposit Ag with a thickness of 200 nm as the electrode on the surface of the electron transport layer at a speed of to obtain a conventional perovskite solar cell.

[0029] The buried bottom interface and cross-section of the perovskite thin film of this perovskite solar cell were obtained through the film tearing technique and liquid nitrogen embrittlement, and were observed by scanning electron microscopy respectively. The results are as shown in Figure 1 and Figure 2 .

[0030] Example 1

[0031] This example prepares a perovskite battery modified with pyrrolidone derivatives. The specific steps are as follows:

[0032] Step One: Ultrasonically clean the conductive glass substrate in sequence with a cleaner, deionized water, ethanol, and isopropanol.

[0033] Step Two: Prepare a Meo-2PACz solution with a concentration of 1.0 mg / ml. Under a nitrogen environment at a temperature of 18 - 25 °C, scrape the hole transport layer on the surface of the conductive glass substrate. Set the height of the doctor blade coater to 50 μm, the plate speed to 5 mm / s, heat the substrate at 25 °C, the nitrogen air knife at 10 kPa. After scraping, anneal it on a hot stage at 100 °C for 15 minutes to complete the preparation of the hole transport layer.

[0034] Step Three: Dissolve oxiracetam in N,N-dimethylformamide and shake it well to prepare an additive solution with a concentration of 1 mg / ml. Prepare a perovskite precursor solution with a concentration of 1.2 mol / ml (FA 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.9 Br 0.1 ) 3. Take 10 μl of the additive solution and add it to 1 ml of the perovskite precursor solution, and oscillate for one hour to fully mix the two.

[0035] Step 4: Set the blade gap of the doctor blade coater to 100 μm, the coating speed to 2 mm / s, the hot plate temperature to 60 °C, the air knife to blow nitrogen at 120 L / min, the incident angle to 90°, and the top blowing distance to 50 mm. Coat the perovskite precursor solution mixed with the additive solution on the surface of the hole transport layer to obtain an oxiracetam-modified perovskite thin film, then irradiate it under an IR lamp at 60 °C for 1 minute, and then anneal it on a hot stage at 130 °C for 1 hour to complete the preparation of the perovskite layer.

[0036] Step 5: Deposit C with a thickness of 27 nm and BCP with a thickness of 8 nm on the surface of the perovskite layer in sequence at a speed of to complete the preparation of the electron transport layer. 60

[0037] Step 6: Deposit Ag with a thickness of 200 nm as the electrode on the surface of the electron transport layer at a speed of to obtain a perovskite solar cell based on pyrrolidone derivative modification.

[0038] Example 2

[0039] In this example, a perovskite solar cell based on pyrrolidone derivative modification is prepared. On the basis of Example 1, aniracetam is dissolved in N,N-dimethylformamide as the additive solution, and the perovskite thin film is modified by aniracetam.

[0040] Example 3

[0041] In this example, a perovskite solar cell based on pyrrolidone derivative modification is prepared. On the basis of Example 1, piracetam is dissolved in N,N-dimethylformamide as the additive solution, and the perovskite thin film is modified by piracetam.

[0042] The buried interface and cross-section of the piracetam-modified perovskite thin film are obtained by the film tearing technique and liquid nitrogen embrittlement, and are observed by scanning electron microscopy respectively. The results are as shown in Figure 3 and Figure 4 .

[0043] The J-V curves of the perovskite solar cells prepared in Comparative Example 1 and Examples 1 to 3 are tested (the effective activation area is 4 square centimeters), and the measurement results of the photovoltaic parameters of the cells are shown in Table 1:

[0044] Table 1 Measurement results of photovoltaic parameters of perovskite solar cells under different formulations

[0045]

[0046] According to Figures 1 to 4 As can be seen from Figures 1 to 4 and the data in Table 1, after adding pyrrolidone derivatives, the holes at the buried interface of the perovskite film are effectively suppressed, and the performance parameters of the battery are significantly improved. Among them, the fill factor and current density are significantly increased, the photoelectric conversion efficiency is significantly improved, the surface non-radiative recombination is significantly suppressed, and the carrier transport is more efficient.

[0047] Example 4

[0048] In this example, a perovskite battery modified with pyrrolidone derivatives was prepared. On the basis of Example 3, aniracetam and piracetam were dissolved in N,N-dimethylformamide as an additive solution.

[0049] Example 5

[0050] In this example, a perovskite battery modified with pyrrolidone derivatives was prepared. On the basis of Example 4, a 2PacZ solution with a concentration of 1.0 mg / ml was prepared for the preparation of the hole transport layer, and Cu was selected as the electrode material.

Claims

1. A perovskite cell modified by a pyrrolidone derivative, comprising, from bottom to top, a conductive glass substrate, a hole transport layer, a perovskite layer, an electron transport layer and an electrode, characterized in that: The perovskite layer is a perovskite doped with a pyrrolidone derivative, wherein the molar ratio of the pyrrolidone derivative to the perovskite is 1:

143.

2. A perovskite cell modified with a pyrrolidone derivative as claimed in claim 1, characterized in that: The pyrrolidone derivative is one or more of oxiracetam, piracetam and aniracetam.

3. A perovskite cell modified with a pyrrolidone derivative as claimed in claim 1, characterized in that: The perovskite is (FA 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.9 Br 0.1 )3.

4. A perovskite cell modified with a pyrrolidone derivative as claimed in claim 1, characterized in that: The hole transport layer material is MeO-2PacZ or 2PacZ, with a thickness of 80 to 130 μm; the thickness of the perovskite layer is 500 to 800 nm; the electron transport layer material is PC 61 BM or C 60 , thickness is 20~30nm; the electrode material is Cu or Ag, thickness is 80~130nm.

5. A method for preparing a perovskite cell modified with a pyrrolidone derivative, wherein the perovskite cell is prepared by a doctor blade method and comprises a conductive glass substrate, a hole transport layer, a perovskite layer, an electron transport layer and an electrode from bottom to top, characterized in that: The pyrrolidone derivative is dissolved in N,N-dimethylformamide to prepare an additive solution with a concentration of 1 mg / ml; the additive solution is added to a perovskite precursor solution with a concentration of 1.2 mol / ml at a volume ratio of 1:100, mixed thoroughly, and then coated on the surface of the hole transport layer to prepare a perovskite layer.

6. A method for preparing a perovskite battery modified with a pyrrolidone derivative as claimed in claim 5, characterized in that: The specific steps include: Step 1: prepare an additive solution and a perovskite precursor solution; add the additive solution to the perovskite precursor solution and stir thoroughly for 1 hour; Step 2: Prepare a Meo-2PACz solution with a concentration of 1.0 mg / ml, apply it to the surface of the cleaned and dried conductive glass substrate, and obtain a hole transport layer after annealing; Step 3: Scrape the perovskite precursor solution mixed with the additive solution onto the surface of the hole transport layer, and anneal for 1 hour to obtain a perovskite layer modified with a pyrrolidone derivative; Step 4: Sequentially evaporate C on the surface of the perovskite layer modified with the pyrrolidone derivative 60 With BCP, an electron transport layer is obtained; Step 5: Vapor-deposit an electrode with a thickness of 200 nm on the surface of the electron transport layer to obtain a perovskite solar cell modified with a pyrrolidone derivative.

7. A method for preparing a perovskite battery modified with a pyrrolidone derivative as claimed in claim 6, characterized in that: When scraping the Meo-2PACz solution, in a nitrogen environment at a temperature of 18 to 25°C, set the blade height of the scraper to 30 to 130 μm, the plate speed to 3 to 6 mm / s, the substrate to 20 to 25°C, the nitrogen air knife to 9 to 12 kPa, and finally anneal at 90 to 110°C for 10 to 15 mins to obtain a hole transport layer.

8. The method for preparing a perovskite battery modified with a pyrrolidone derivative according to claim 6, characterized in that: When scraping the perovskite precursor solution, under a nitrogen environment, the gap of the scraper was set to 100 μm, the coating speed was 2 mm / s, the hot plate temperature was 60 °C, the air knife was at 120 L / min, the incident angle was 90°, and the top blowing distance was 50 mm.

9. A method for preparing a perovskite cell modified with a pyrrolidone derivative as claimed in claim 8, characterized in that: After the perovskite precursor solution was coated, it was irradiated under an IR lamp at 60°C for 1 minute and then annealed at 130°C for 1 hour to obtain a perovskite layer modified with a pyrrolidone derivative.

10. The method for preparing a perovskite battery modified with a pyrrolidone derivative according to claim 6, characterized in that: by The electron transport layer and electrodes are evaporated at a speed of 1000 nm.

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