Preparation method of perovskite solar cell

Abstract

The invention discloses a preparation method of a perovskite solar cell. The preparation method comprises the following steps: step 1) preparing a SnO2 layer on transparent conductive glass; (2) a solution containing PbI2, PbBr2, CsI and NpMAI is heated and stirred at the temperature of 60-80 DEG C to react for 11-13 h, then the SnO2 layer is coated with the solution, annealing is conducted for 8-12 s at the temperature of 65-75 DEG C, and an inorganic layer is obtained; (3) a solution containing FAI, MAI and MACl is heated, stirred and reacted for 20-40 min at the temperature of 60-80 DEG C, then the inorganic layer is coated with the solution, and annealing is conducted for 1-5 min under the conditions that the air humidity is 40%-50% and the temperature is 170-180 DEG C; then annealing for 5-15 minutes under the conditions that the air humidity is 40-50% and the temperature is 140-160 DEG C to obtain an organic layer; and 4) sequentially preparing a passivation layer, a hole transport layer and an electrode layer on the organic layer.

Description

Technical Field

[0001] The present invention relates to the field of solar cells, and in particular to a method for preparing a perovskite solar cell. Background Art

[0002] Organic-inorganic halide perovskite materials are considered to be the most promising new photovoltaic materials for commercialization due to their excellent optoelectronic properties, long carrier diffusion length, strong light absorption and low processing cost. After decades of development, the power conversion efficiency of single-junction perovskite solar cells has rapidly increased from 3.8% to 26.7%, approaching the Shockley-Queisser limit. In order to further improve the photon absorption efficiency of solar cells, the construction of a stacked cell consisting of a wide-bandgap perovskite top cell and a c-Si solar cell has become a hot topic in academia and industry.

[0003] Due to its special charge transfer mechanism, perovskite cells are prone to performance hysteresis, that is, there is a large difference in performance when applying forward voltage and reverse voltage. The above shortcomings limit the commercialization and practical application of perovskite cells. In the process of forming perovskite crystals, the existing continuous annealing process causes the crystallization process to be non-uniform due to the uncontrollability of the perovskite crystallization process, and the grain growth rate at various positions in the film is different, resulting in loose contact between grain boundaries and large gaps. Summary of the invention

[0004] The present invention provides a method for preparing a perovskite solar cell to reduce the performance hysteresis problem of the perovskite solar cell. The present invention can be implemented by the following technical solutions:

[0005] A method for preparing a perovskite solar cell comprises the following steps:

[0006] Step 1) preparing a SnO2 layer on a transparent conductive glass;

[0007] Step 2) heating a solution containing PbI2, PbBr2, CsI and NpMAI at 60-80°C with stirring for 11-13h, coating the solution on the SnO2 layer, and annealing the solution at 65-75°C for 8-12s to obtain an inorganic layer;

[0008] Step 3) heating the solution containing FAI, MAI and MACl at 60-80°C with stirring for 20-40 minutes, coating the solution on the inorganic layer, annealing for 1-5 minutes at an air humidity of 40%-50% and a temperature of 170-180°C; then annealing for 5-15 minutes at an air humidity of 40%-50% and a temperature of 140-160°C to obtain an organic layer;

[0009] Step 4) sequentially preparing a passivation layer, a hole transport layer and an electrode layer on the organic layer.

[0010] Optionally, in the step 1), the solution containing SnO2 is spin-coated on the transparent conductive glass at a spin-coating speed of 2500-3500 rpm for 25-35 s. After the spin-coating is completed, annealing is performed at 140-160°C for 20-40 min, and then cooling is performed to form a SnO2 layer.

[0011] Optionally, the step 1) further includes placing the transparent conductive glass spin-coated with the SnO2 layer into a UV-ozone box for UV-ozone treatment for 10 minutes.

[0012] Optionally, in the step 2), the mass ratio of PbI2:PbBr2:CsI is 0.7-0.75:0.3-0.25:0.001-0.003, and the mass of NpMAI is 4-6‰ of the mass of PbI2.

[0013] Optionally, in the step 2), the solution containing PbI2, PbBr2, CsI and NpMAI is heated at 60-80°C and stirred for reaction for 11-13 hours and then spin-coated on the SnO2 layer at a spin-coating speed of 1800-2000 rpm and a spin-coating time of 25-35 seconds.

[0014] Optionally, in the step 3), the mass ratio of FAI:MAI:MACl is 75-78:15-12:16-20.

[0015] Optionally, the solution containing FAI, MAI and MACl is heated at 60-80° C. and stirred for 25-35 min, and then spin-coated on the inorganic layer at a spin-coating speed of 2000-2500 rpm and a spin-coating time of 35-45 s.

[0016] Optionally, in the step 3), annealing is performed at an air humidity of 40%-50% and a temperature of 170-180° C. for 3 minutes; and then annealing is performed at an air humidity of 40%-50% and a temperature of 150° C. for 10-15 minutes.

[0017] Optionally, the passivation layer is at least one of BABr, BAI, NpMABr, NpMAI, PEABr, PEAI, and BnBr passivation layers;

[0018] The hole transport layer is made of at least one of Spiro-OMeTAD, PTAA, NiOx, and MoOx;

[0019] The electrode layer is made of Ag 、 At least one of Cu and Au.

[0020] The present invention also provides a perovskite solar cell prepared by the above-mentioned perovskite solar cell preparation method.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The preparation method of the present invention adopts a step-by-step annealing method to anneal the organic layer of the perovskite solar cell, which can effectively reduce the hysteresis problem of the perovskite solar cell. In addition, the present invention proposes optimal annealing parameters for the applied perovskite material, which is helpful to produce a perovskite solar cell with excellent performance. DETAILED DESCRIPTION

[0023] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0024] The terms "include", "comprising", "having", "containing", etc. used herein are all open terms, which mean including but not limited to. The raw materials used in each embodiment are all commercially available products.

[0025] Example 1

[0026] Step 1) Prepare a SnO2 solution, spin-coat the SnO2 solution on the ITO transparent conductive glass at 3000 rpm for 30 seconds, then anneal at 150°C for 30 minutes, and after cooling, treat with UV ozone for 10 minutes to form a SnO2 layer.

[0027] Step 2) PbI 2、 PbB 2、 CsI ​​and NpMAI were dissolved in a DMF / DMSO (volume ratio 94 / 6) mixed solution, PbI2:PbBr2:CsI=0.73:0.27:0.002, NpMAI and PbI2 mass ratio was 5‰, and then stirred at 70°C for 12h. The solution was then spin-coated on the SnO2 layer at a speed of 1900rpm for 30s, then annealed at 70°C for 10s, and cooled to room temperature to form an inorganic layer.

[0028] Step 3) 76.5 mg FAI, 13.5 mg MAI, and 18 mg MACl were dissolved in 1 ml IPA, and heated and stirred at 70° C. for 30 min. The solution was then spin-coated on the inorganic layer at a speed of 2300 rpm for 40 s, and then immediately annealed in air at 170° C. for 1 min, and then annealed at 150° C. for 5 min, with the air humidity being 40-50% during the annealing process, to form an organic layer.

[0029] Step 4) BABr was dissolved in IPA at a concentration of 4 mg / ml to obtain a BABr solution, which was spin-coated on the organic layer at a speed of 4000 rpm for 30 seconds and annealed at 80° C. for 5 minutes.

[0030] Step 5) Preparation of Spiro-OMeTAD hole transport layer

[0031] a. Use an electronic balance to accurately weigh 260 mg of Li-TFSI into a sample bottle, add 1 mL of anhydrous acetonitrile in a glove box, and stir at room temperature for 1 h to dissolve it.

[0032] b. Use an electronic balance to accurately weigh 80 mg of Spiro-OMeTAD into a sample bottle, add 1 mL of chlorobenzene in a glove box, stir for 2 hours at room temperature in the dark, add 30 μL of t-BP, stir evenly, then add 35 μL of Li-TFSI (260 mg / mL) solution for doping, stir for 2 hours at room temperature to obtain a Spiro-OMeTAD hole transport layer solution. Spin-coat the Spiro-OMeTAD solution at 6000 rpm for 30 seconds, and then transfer to an air drying oven for oxidation for about 10 hours.

[0033] Step 6) Preparing a Ag electrode on the hole transport layer.

[0034] Example 2

[0035] Compared with Example 1, the annealing treatment was modified to annealing at 170° C. for 1 min, and then annealing at 150° C. for 10 min. Other conditions were the same as those in Example 1.

[0036] Example 3

[0037] Compared with Example 1, the annealing treatment was modified to annealing at 170° C. for 1 min, and then annealing at 150° C. for 15 min. Other conditions were the same as those in Example 1.

[0038] Example 4

[0039] Compared with Example 1, the annealing treatment was modified to annealing at 180° C. for 3 min and then annealing at 150° C. for 10 min. Other conditions were the same as those in Example 1.

[0040] Example 5

[0041] Compared with Example 1, the annealing treatment was modified to annealing at 170° C. for 3 min and then annealing at 150° C. for 10 min. Other conditions were the same as those in Example 1.

[0042] Example 6

[0043] Compared with Example 1, the annealing treatment was modified to annealing at 170° C. for 3 min and then annealing at 150° C. for 15 min. Other conditions were the same as those in Example 1.

[0044] Example 7

[0045] Compared with Example 1, the annealing treatment was modified to annealing at 175° C. for 5 min and then annealing at 145° C. for 10 min. Other conditions were the same as those in Example 1.

[0046] Example 8

[0047] Compared with Example 1, the annealing treatment was modified to annealing at 175° C. for 5 min and then annealing at 155° C. for 5 min. Other conditions were the same as those in Example 1.

[0048] Example 9

[0049] Compared with Example 1, the annealing treatment was modified to annealing at 180° C. for 1 min, and then annealing at 160° C. for 5 min. Other conditions were the same as those in Example 1.

[0050] Compared with Example 1, the annealing time in step 3) is adjusted, as shown in Table 1.

[0051] Comparative Example 1

[0052] The annealing treatment in step 3) of Example 1 was modified to annealing at 170° C. for 15 min.

[0053] Table 1 Performance test results of the embodiment

[0054]

[0055]

[0056] The experimental results show that the hysteresis factor decreases during step annealing. The best results can be obtained by annealing at 170-180℃ for 3min and 150℃ for 10-15min.

[0057] Comparative Example 2

[0058] Compared with Example 1, the annealing treatment in step 3) is modified to first treating at 150° C. for 1 min and then treating at 170° C. for 15 min.

[0059] Comparative Example 3

[0060] Compared with Example 1, the annealing treatment in step 3) is modified to first treating at 130° C. for 5 min and then treating at 170° C. for 15 min.

[0061] Table 2 Comparative performance test results

[0062]

[0063]

[0064] It can be seen from Table 2 that low-temperature annealing followed by high-temperature annealing cannot achieve a good hysteresis reduction effect.

[0065] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for preparing a perovskite solar cell, characterized in that: The steps include: Step 1) preparing a SnO2 layer on a transparent conductive glass; Step 2) heating a solution containing PbI2, PbBr2, CsI and 1-naphthylmethylamine iodide at 60-80°C with stirring for 11-13h, coating the solution on the SnO2 layer, and annealing the solution at 65-75°C for 8-12s to obtain an inorganic layer; Step 3) heating a solution containing formamidine hydroiodide, methyl ammonium iodide and methyl ammonium chloride at 60-80° C. with stirring for 20-40 min, coating the solution on the inorganic layer, annealing the solution at 40%-50% humidity and 170-180° C. for 1-5 min; then annealing the solution at 40%-50% humidity and 140-160° C. for 5-15 min to obtain an organic layer; Step 4) sequentially preparing a passivation layer, a hole transport layer and an electrode layer on the organic layer.

2. The method for preparing a perovskite solar cell according to claim 1, characterized in that: In the step 1), a solution containing SnO2 is spin-coated on the transparent conductive glass at a spin-coating speed of 2500-3500 rpm for 25-35 seconds. After the spin-coating is completed, the glass is annealed at 140-160°C for 20-40 minutes. After the annealing is completed, the glass is cooled to form a SnO2 layer.

3. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The step 1) also includes placing the transparent conductive glass spin-coated with the SnO2 layer into a UV-ozone box for UV-ozone treatment for 10 minutes.

4. The method for preparing a perovskite solar cell according to claim 1, characterized in that: In the step 2), the mass ratio of PbI2:PbBr2:CsI is 0.7-0.75:0.3-0.25:0.001-0.003, and the mass of 1-naphthylmethylamine iodide is 4-6‰ of the mass of PbI2.

5. The method for preparing a perovskite solar cell according to claim 1, characterized in that: In the step 2), a solution containing PbI2, PbBr2, CsI and 1-naphthylmethylamine iodide is heated at 60-80°C and stirred for reaction for 11-13 hours, and then spin-coated on the SnO2 layer at a spin-coating speed of 1800-2000 rpm and a spin-coating time of 25-35 seconds.

6. The method for preparing a perovskite solar cell according to claim 1, characterized in that: In the step 3), the mass ratio of formamidine hydroiodide: methylammonium iodide: methylammonium chloride is 75-78: 15-12: 16-20.

7. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The solution containing formamidine hydroiodide, methylammonium iodide and methylammonium chloride is heated at 60-80° C. and stirred for 25-35 minutes, and then spin-coated on the inorganic layer at a spin-coating speed of 2000-2500 rpm and a spin-coating time of 35-45 seconds.

8. The method for preparing a perovskite solar cell according to claim 1, characterized in that: In the step 3), the annealing is performed at a temperature of 170-180° C. and a humidity of 40%-50% for 3 minutes; and then the annealing is performed at a temperature of 150° C. and a humidity of 40%-50% for 10-15 minutes.

9. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The passivation layer is at least one of BABr, BAI, NpMABr, NpMAI, PEABr, PEAI, and BnBr passivation layers; The hole transport layer uses at least one of Spiro-OMeTAD, PTAA, NiOx, and MoOx; and the electrode layer uses at least one of Ag, Cu, and Au. 10 . The perovskite solar cell prepared by the method for preparing a perovskite solar cell according to claim 1 .

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