A composite passivation layer modified trans-perovskite solar cell and a preparation method thereof

Abstract

The application discloses a kind of composite passivation layer modified transverse perovskite solar cell and preparation method thereof, the perovskite solar cell structure includes sequentially stacked base electrode, hole transport layer, perovskite layer, composite passivation layer, electron transport layer, hole blocking layer and metal electrode.The composite passivation layer of the application is inserted between perovskite layer and electron transport layer using solution method, the composite passivation layer can passivate perovskite layer bulk phase and surface defects, reduce non-radiative recombination center, improve the electron transport efficiency between perovskite layer and electron transport layer, finally obtain high-efficiency stable perovskite solar cell.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solar cells, and particularly relates to a composite passivation layer modified anti-perovskite solar cell and a preparation method thereof. BACKGROUND

[0002] Photovoltaic technology has become one of the most popular and most widely used renewable energy sources in the world due to its advantages of wide distribution, no pollution, low cost and the like. At present, the first generation of crystalline silicon solar cells and the second generation of amorphous silicon and oxide thin film solar cells are mainly used in the market. The certified efficiency of the third generation of perovskite solar cells has reached 26.7% after nearly ten years of development. Compared with the first and second generation of solar cells, a single-junction perovskite solar cell has higher theoretical efficiency, lower theoretical cost due to low material purity requirement and small amount of use, and good commercial prospects due to flexible preparation and diversified application scenarios.

[0003] However, perovskite solar cells still face many challenges in realizing commercialization. First, the crystallization speed of perovskite thin films prepared by a solution method is fast and difficult to control, and a large number of uncoordinated lead and iodine vacancies are inevitably generated, which eventually become the center of non-radiative recombination, block the transmission of electrons or holes, and damage the performance of the device. Second, due to the soft lattice nature of perovskite materials, lattice distortion easily occurs, and when subjected to external factors such as water, oxygen, ultraviolet light and temperature, lattice collapse easily occurs, eventually leading to a decrease in device efficiency. Third, perovskite materials have a serious ion migration phenomenon, which not only corrodes the electrodes of the device, but also causes short circuit of the device. Fourth, the reported passivation materials have poor universality, and only have optimization effect on perovskite cells with specific components, and are difficult to repeat or difficult to expand to other component perovskite cells. Therefore, it is crucial to seek efficient and highly universal passivation materials to passivate the surface defects of perovskite, inhibit ion migration, and improve the efficiency and stability of the device. SUMMARY

[0004] The application aims to provide a composite passivation layer modified anti-perovskite solar cell, and aims to solve the problems of many defects in perovskite layers, serious ion migration, poor universality of passivation materials and the like, and help to improve the performance of the device. The application also aims to provide a preparation method of the composite passivation layer modified anti-perovskite solar cell.

[0005] Technical Solution: The composite passivation layer modified inverse perovskite solar cell of the present invention comprises, from bottom to top, a substrate electrode, a hole transport layer, a perovskite layer, a composite passivation layer, an electron transport layer, a hole blocking layer, and a metal electrode. The composite passivation layer comprises two components, a and b. Component a is 2-amino-5-mercapto-1,3,4-thiadiazole, 2-mercapto-5-methyl-1,3,4-thiadiazole, 2-mercapto-1,3,4-thiadiazole, 1,3,4-thiadiazole, or 2,5-dimercaptothiadiazole dimer; component b is phenylethyl iodide, phenylethyl bromide, phenylethyl ammonium chloride, 3-fluorophenylethyl bromide, 3-fluorophenylethyl iodide, monoiodopiperazine, 9-octadecenyl iodide, or octyl iodide.

[0006] Furthermore, the crystal structure of the perovskite layer is ABX3, where A is CH3NH3. + (MA + ), NH2CH=NH2 + (FA + ), Cs + or Rb + At least one of them; B is Pb 2+ and Sn 2+ One or two of them; X is Cl - ,Br - or I - At least one of them.

[0007] Furthermore, the thickness of the composite passivation layer is 1-100 nm, and the perovskite grain size after the composite passivation layer modifies the perovskite layer is 0.2-2 μm.

[0008] Preferably, the perovskite grain size after the composite passivation layer modifies the perovskite layer is 0.3 to 1.5 μm.

[0009] The method for preparing the composite passivation layer modified inverse perovskite solar cell of the present invention includes the following steps:

[0010] A hole transport layer, a perovskite layer, a composite passivation layer, an electron transport layer, and a hole blocking layer are sequentially fabricated on the substrate electrode. Finally, an electrode is deposited on the surface of the hole blocking layer by vapor deposition.

[0011] Furthermore, the process of preparing the composite passivation layer includes: dissolving components a and b in a solvent and spin-coating them onto the surface of the perovskite layer. The concentration of component a dissolved in the solvent is 0.1-10 mg / mL, and the concentration of component b dissolved in the solvent is 0.1-8 mg / mL.

[0012] Preferably, the concentration of component a dissolved in the solvent is 0.2-9 mg / mL, and the concentration of component b dissolved in the solvent is 0.2-7 mg / mL.

[0013] Further, the film forming method of the perovskite layer is one of spin coating, doctor blade coating, spray coating or inkjet printing.

[0014] Further, the whole preparation process is carried out in air or N2 atmosphere.

[0015] Beneficial effects: Compared with the prior art, the present application has the following remarkable advantages: first, the synergistic effect of the a component and the b component is fully exerted. The b component usually forms a 2D perovskite layer on the perovskite surface to improve the battery voltage, but cannot passivate the perovskite bulk phase defects, while the a component can penetrate into the perovskite bulk phase to passivate the perovskite bulk defects. Therefore, after the perovskite layer is modified by the composite passivation layer, the perovskite bulk surface defects are comprehensively passivated, which is more conducive to improving the performance parameters of the perovskite solar cell; second, the composite passivation layer technology proposed by the present application has good repeatability and universality, and good passivation effect can be obtained regardless of whether the A position of the perovskite is one, two or more cations, or whether the optical band gap of the perovskite is a conventional band gap or a wide band gap. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 J-V curve and performance parameters of the perovskite solar cell of Example 1 of the present application;

[0017] Figure 2 J-V curve and performance parameters of the perovskite solar cell of Comparative Example 1 of the present application;

[0018] Figure 3 J-V curve and performance parameters of the perovskite solar cell of Comparative Example 2 of the present application;

[0019] Figure 4 Scanning electron microscope pictures of Example 1, Comparative Example 1 and Comparative Example 2 of the present application;

[0020] Figure 5 J-V curve and performance parameters of the perovskite solar cell of Example 2 of the present application;

[0021] Figure 6 J-V curve and performance parameters of the perovskite solar cell of Example 3 of the present application;

[0022] Figure 7 J-V curve and performance parameters of the perovskite solar cell of Example 4 of the present application. DETAILED DESCRIPTION

[0023] The technical solutions of the present application will be further described below in combination with the drawings.

[0024] Example 1

[0025] Step 1, indium-doped tin oxide conductive glass (ITO) was respectively placed in a mixture of deionized water and detergent (1:50, v:v), deionized water, ethanol, isopropanol, and ultrasonic for 15 min to obtain clean substrate glass;

[0026] Step 2, after the clean ITO glass was dried, it was transferred to a UV ozone machine (UV) for 30 min for standby;

[0027] Step 3, spin-coat the MeO-2PACz hole transport layer (concentration of 0.5 mg / mL ethanol solution) on the ITO substrate, spin-coat speed is 3000 rpm, spin-coat time is 30 s, immediately after spin-coat, place it on a heating stage at 100℃ for 10 min;

[0028] Step 4, take 40 μL perovskite solution and drop it on the hole transport layer, spin-coat at 1000 rpm for 10 s, spin-coat at 3000 rpm for 40 s, drop 150 μL chlorobenzene quickly at the second stage for 25 s, extract the solvent to promote crystallization. After spin-coat, immediately place it on a heating stage at 100℃ for 10 min annealing, the obtained perovskite band gap is 1.55 eV. The perovskite solution is 1.5 MRb 0.05 Cs 0.05 MA 0.05 FA 0.85 Pb(I 0.95 Br 0.05 )3 dissolved in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide with a volume ratio of 4:1, all operations were carried out in a nitrogen atmosphere;

[0029] Step 5, spin-coat 1 mg / mL phenethylammonium bromide and 2 mg / mL 2-amino-5-mercapto-1,3,4-thiadiazole in isopropanol solution on the perovskite surface, spin-coat speed is 5000 rpm, spin-coat time is 30 s, after spin-coat, anneal at 100℃ for 10 min to passivate perovskite defects;

[0030] Step 6, spin-coat PC 61 BM electron transport layer on the surface of the composite passivation layer, PC 61 BM solution concentration is 20 mg / mL, spin-coat speed is 3000 rpm, spin-coat time is 30 s, after spin-coat, anneal at 70℃ for 10 min;

[0031] Step 7, spin-coat bathocuproin (BCP) as a hole blocking layer on the electron transport layer, BCP solution concentration is 0.5 mg / mL, spin-coat speed is 4000 rpm, spin-coat time is 30 s, after spin-coat, anneal at 70℃ for 10 min;

[0032] Step 8, finally, 100 nm of Ag electrode was evaporated on the hole blocking layer.

[0033] The J-V curves and performance parameters of the perovskite solar cells of Example 1 are shown in Figure 1 .

[0034] Example 2

[0035] The difference between the preparation method of this example and Example 1 is (the remaining steps are the same):

[0036] The perovskite band gap is 1.59 eV, and the perovskite solution is 1.5M FA 0.85 Cs 0.15 Pb(I 0.95 Br 0.05 )3 perovskite is dissolved in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4:1. The perovskite is spin-coated on the surface of the hole transport layer at a speed of 6000 rpm for 60 s, and 150 μL of chlorobenzene is quickly added as an anti-solvent to promote crystallization at the 15th s. All operations are carried out in a nitrogen atmosphere;

[0037] The composite passivation layer solution is 1 mg of phenethylammonium bromide and 1.5 mg of 2-mercapto-1,3,4-thiadiazole dissolved in 1 mL of a mixed solution of isopropanol and DMF (200:1, v:v).

[0038] The J-V curves and performance parameters of the perovskite solar cells of Example 2 are shown in Figure 5 .

[0039] Example 3

[0040] The difference between the preparation method of this example and Example 1 is (the remaining steps are the same):

[0041] The composite passivation layer solution is 1 mg of phenethylammonium bromide and 1.5 mg of 2-mercapto-1,3,4-thiadiazole dissolved in 1 mL of a mixed solution of isopropanol and DMF (200:1, v:v).

[0042] The J-V curves and performance parameters of the perovskite solar cells of Example 3 are shown in Figure 6 .

[0043] Example 4

[0044] The difference between the preparation method of this example and Example 1 is (the remaining steps are the same):

[0045] The perovskite band gap is 1.53 eV, and the perovskite solution is 1.5M FA 0.85 MA 0.1 Cs 0.05PbI3perovskite was dissolved in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide with a volume ratio of 4:1. The perovskite was spin-coated on the surface of the hole transport layer with a rotation speed of 1000 rpm for 10 s and 5000 rpm for 40 s, and 200 μL chlorobenzene was quickly added as an anti-solvent to promote crystallization at the 5th second of the last spin. All operations were carried out under a nitrogen atmosphere.

[0046] The composite passivation layer solution was prepared by dissolving 1 mg of 3-fluorophenethylammonium iodide and 2 mg of 2-amino-5-mercapto-1,3,4-thiadiazole in 1 mL of isopropanol.

[0047] The J-V curves and performance parameters of the perovskite solar cells of Example 4 are shown in Figure 7 .

[0048] Comparative Example 1

[0049] The preparation method of this comparative example is different from that of Example 1 (the remaining steps are the same) in that no passivation modification treatment is performed between the perovskite layer and the electron transport layer. The J-V curves and performance parameters of the perovskite solar cells are shown in Figure 2 .

[0050] Comparative Example 2

[0051] The preparation method of this comparative example is different from that of Example 1 (the remaining steps are the same) in that an isopropanol solution of 1 mg / mL phenethylammonium bromide is spin-coated on the surface of the perovskite as a top interfacial passivation treatment. The J-V curves and performance parameters of the perovskite solar cells are shown in Figure 3 . The scanning electron microscope pictures of Example 1, Comparative Example 1 and Comparative Example 2 are shown in Figure 4 .

Claims

1. A composite passivation layer modified trans-faimass solar cell, comprising a substrate electrode, a hole transport layer, a perovskite layer, a composite passivation layer, an electron transport layer, a hole blocking layer and a metal electrode stacked in order from bottom to top, characterized in that: The composite passivation layer comprises two components a and b, the component a is 2-amino-5-mercapto-1, 3, 4-thiadiazole, 2-mercapto-5-methyl-1, 3, 4-thiadiazole, 2-mercapto-1, 3, 4-thiadiazole, 1, 3, 4-thiadiazole or 2, 5-dimercaptothiadiazole dimer, and the component b is phenethyl iodide amine, phenethyl bromide amine, phenethyl chloride amine, 3-fluorophenethyl bromide amine, 3-fluorophenethyl iodide amine, monoiodophenazine, 9-octadecenyl iodide amine or octyl iodide amine.

2. The composite passivation layer-modified trans -perovskite solar cell according to claim 1, characterized in that: The crystal structure of the perovskite layer is ABX3, wherein A is at least one of CH3NH3 + (MA + ), NH2CH=NH2 + (FA + ), Cs + or Rb + , B is one or both of Pb 2+ and Sn 2+ , and X is at least one of Cl - , Br - or I - .

3. The composite passivation layer-modified trans-faimiliar perovskite solar cell according to claim 1, characterized in that: The thickness of the composite passivation layer is 1-100 nm.

4. The composite passivation layer-modified trans-faimiliar perovskite solar cell according to claim 1, characterized in that: The size of the perovskite crystal grains after the perovskite layer is modified by the composite passivation layer is 0.2-2 μm.

5. A method for preparing a composite passivation layer modified trans- perovskite solar cell according to any one of claims 1-4, characterized in that: The method comprises the following steps: A hole transport layer, a perovskite layer, a composite passivation layer, an electron transport layer and a hole blocking layer are prepared on a substrate electrode in sequence, and finally an electrode is evaporated on the surface of the hole blocking layer.

6. The method of claim 5, wherein the method is characterized by: The process for preparing the composite passivation layer comprises dissolving the components a and b in a solvent and spin coating on the surface of the perovskite layer.

7. The method of claim 6, wherein the method is characterized by: The concentration of the component a dissolved in the solvent is 0.1-10 mg / mL.

8. The method of claim 6, wherein the method is characterized by: The concentration of the component b dissolved in the solvent is 0.1-8 mg / mL.

9. The method of claim 5, wherein the method is characterized by: The film forming mode of the perovskite layer is spin coating, doctor blade coating, spraying or inkjet printing.

10. The method of claim 5, wherein the method is characterized by: The whole preparation process is carried out in air or N2 atmosphere.

Images