Composite passivation layer modified trans-perovskite solar cell and preparation method thereof

Abstract

The invention discloses a composite passivation layer modified trans-perovskite solar cell and a preparation method thereof. The perovskite solar cell structurally comprises a substrate electrode, a hole transport layer, a perovskite layer, a composite passivation layer, an electron transport layer, a hole barrier layer and a metal electrode which are sequentially stacked. The composite passivation layer is inserted between the perovskite layer and the electron transport layer by adopting a solution method, and the composite passivation layer can passivate bulk phase and surface defects of the perovskite layer, reduce non-radiative recombination centers, improve the electron transport efficiency between the perovskite layer and the electron transport layer, and finally obtain the efficient and stable perovskite solar cell.

Description

Technical Field

[0001] The invention belongs to the technical field of solar cells, and in particular relates to a composite passivation layer modified inverse perovskite solar cell and a preparation method thereof. Background Art

[0002] Photovoltaic technology has become one of the most popular and widely used renewable energy sources in the world due to its advantages such as wide distribution, no pollution and low cost. At present, the market is mainly dominated by first-generation crystalline silicon solar cells and second-generation thin-film solar cells made of amorphous silicon and oxides. After nearly ten years of development, the certified efficiency of the third-generation perovskite solar cells has reached 26.7%. Compared with the first and second generation solar cells, single-cell perovskite solar cells have higher theoretical efficiency; low material purity requirements, small dosage, and lower theoretical cost; flexible preparation, diversified application scenarios, and good commercial prospects.

[0003] However, perovskite solar cells still face many challenges on the road to commercialization. First, the solution method for preparing perovskite films has a fast crystallization speed and is difficult to control, which inevitably produces a large number of defects such as uncoordinated lead and iodine vacancies, which eventually become the center of non-radiative recombination, blocking the transmission of electrons or holes and destroying the performance of the device. Second, due to the soft lattice properties of the perovskite material itself, lattice distortion is prone to occur. When disturbed by external factors such as water, oxygen, ultraviolet rays and temperature, the lattice collapses easily, eventually leading to reduced device efficiency. Third, perovskite materials have serious ion migration phenomena, which not only corrodes the electrodes of the device, but also causes short circuits in the device. Fourth, the passivation materials currently reported have poor universality and only have an optimization effect on perovskite batteries of specific compositions. It is difficult to repeat or expand to other components of perovskite batteries. Therefore, it is crucial to seek efficient and universal passivation materials to passivate perovskite surface defects, inhibit ion migration, and improve the efficiency and stability of the device. Summary of the invention

[0004] Purpose of the invention: The present invention aims to provide a composite passivation layer modified inverse perovskite solar cell, aiming to solve the problems of many defects in the perovskite layer, serious ion migration, poor universality of passivation materials, etc., which is helpful to improve device performance; the present invention also aims to provide a preparation method of the composite passivation layer modified inverse perovskite solar cell.

[0005] Technical solution: The composite passivation layer modified trans-perovskite solar cell described in the present invention comprises 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 sequence from bottom to top, wherein the composite passivation layer comprises two components a and b, wherein 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 phenethylammonium iodide, phenethylammonium bromide, phenethylammonium chloride, 3-fluorophenethylammonium bromide, 3-fluorophenethylammonium iodide, monoiodopiperazine, 9-octadecenylammonium iodide or octylammonium iodide.

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

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

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

[0009] The method for preparing the composite passivation layer modified inverse perovskite solar cell of the present invention comprises 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 prepared on the base electrode, and finally an electrode is evaporated on the surface of the hole blocking layer.

[0011] Furthermore, the process of preparing the composite passivation layer includes: dissolving components a and b in a solvent and spin coating them on the surface of the perovskite layer, wherein 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] Furthermore, the perovskite layer is formed by a spin coating method, a doctor blade coating method, a spray coating method or an inkjet printing method.

[0014] Furthermore, the entire preparation process is carried out under air or N2 atmosphere.

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

[0016] Figure 1 The JV curve and performance parameters of the perovskite solar cell of Example 1 of the present invention;

[0017] Figure 2 The JV curve and performance parameters of the perovskite solar cell of Comparative Example 1 of the present invention;

[0018] Figure 3 The JV curve and performance parameters of the perovskite solar cell of Comparative Example 2 of the present invention;

[0019] Figure 4 The scanning electron microscope images of Example 1, Comparative Example 1 and Comparative Example 2 of the present invention are shown;

[0020] Figure 5 The JV curve and performance parameters of the perovskite solar cell of Example 2 of the present invention;

[0021] Figure 6 The JV curve and performance parameters of the perovskite solar cell of Example 3 of the present invention;

[0022] Figure 7 1 and 2. JV curve and performance parameters of the perovskite solar cell of Example 4 of the present invention. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0024] Example 1

[0025] Step 1, indium-doped tin oxide conductive glass (ITO) is placed in a mixed liquid of deionized water and detergent (1:50, v:v), deionized water, ethanol, and isopropanol, and ultrasonicated for 15 minutes each to obtain a clean substrate glass;

[0026] Step 2, after drying the cleaned ITO glass, transfer it to an ultraviolet ozone machine (UV) for treatment for 30 minutes for standby use;

[0027] Step 3, spin-coat the MeO-2PACz hole transport layer (ethanol solution with a concentration of 0.5 mg / mL) on the ITO substrate at a spin-coating speed of 3000 rpm for 30 s, and immediately heat it on a heating table at 100 °C for 10 min after spin-coating;

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

[0029] Step 5, 1 mg / mL of phenethylammonium bromide and 2 mg / mL of 2-amino-5-mercapto-1,3,4-thiadiazole were dissolved in isopropanol and then spin-coated on the perovskite surface at a speed of 5000 rpm for 30 seconds. After spin coating, the perovskite was annealed at 100° C. for 10 minutes to passivate the perovskite defects.

[0030] Step 6: Spin-coat PC on the surface of the composite passivation layer 61 BM electron transport layer, PC 61 The concentration of BM solution was 20 mg / mL, the spin coating speed was 3000 rpm, the spin coating time was 30 s, and after spin coating, annealing was performed at 70 °C for 10 min;

[0031] Step 7, spin-coating bathocuproin (BCP) on the electron transport layer as a hole blocking layer, the concentration of the BCP solution is 0.5 mg / mL, the spin-coating speed is 4000 rpm, the spin-coating time is 30 s, and annealing is performed at 70° C. for 10 min after spin-coating;

[0032] Step 8: Finally, a 100 nm thick Ag electrode is evaporated on the hole blocking layer.

[0033] Example 1 JV curve and performance parameters of perovskite solar cells refer to Figure 1 .

[0034] Example 2

[0035] The preparation method of this embodiment is different from that of embodiment 1 in that (the remaining steps are the same):

[0036] The perovskite band gap is 1.59eV, and the perovskite solution is 1.5M FA 0.85 Cs 0.15 Pb(I 0.95 Br 0.05 )3 Perovskite 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 at a speed of 6000 rpm for 60 s. At the 15th s, 150 μL of chlorobenzene was quickly added as an anti-solvent to promote crystallization. All operations were carried out under 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] Example 2 JV curve and performance parameters of perovskite solar cells refer to Figure 5 .

[0039] Example 3

[0040] The preparation method of this embodiment is different from that of embodiment 1 in that (the remaining steps are the same):

[0041] The composite passivation layer solution was prepared by dissolving 1 mg of phenethylammonium iodide and 1.5 mg of 2-amino-5-mercapto-1,3,4-thiadiazole in 1 mL of isopropanol.

[0042] Example 3 JV curve and performance parameters of perovskite solar cells Figure 6 .

[0043] Example 4

[0044] The preparation method of this embodiment is different from that of embodiment 1 in that (the remaining steps are the same):

[0045] The perovskite band gap is 1.53 eV and the perovskite solution is 1.5 M FA 0.85 MA 0.1 Cs 0.05PbI3 perovskite 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 at a speed of 1000 rpm for 10 s and 5000 rpm for 40 s. 200 μL of chlorobenzene was quickly added as an anti-solvent at the last 5 seconds to promote crystallization. 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] Example 4 JV curve and performance parameters of perovskite solar cells Figure 7 .

[0048] Comparative Example 1

[0049] The difference between the preparation method of this comparative example and that of Example 1 is that (the rest of the steps are the same): no passivation modification is performed between the perovskite layer and the electron transport layer. The JV curve and performance parameters of the perovskite solar cell are shown in Figure 2 .

[0050] Comparative Example 2

[0051] The difference between the preparation method of this comparative example and that of Example 1 is that (the rest of the steps are the same): 1 mg / mL of phenethylammonium bromide isopropanol solution is spin-coated on the surface of the perovskite as a top interface passivation treatment. The JV curve and performance parameters of the perovskite solar cell are shown in Figure 3 See the SEM images of Example 1, Comparative Example 1 and Comparative Example 2. Figure 4 .

Claims

1. A composite passivation layer modified inverse perovskite 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 sequence from bottom to top, characterized in that: The composite passivation layer comprises two components, a and b, wherein 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 phenethylammonium iodide, phenethylammonium bromide, phenethylammonium chloride, 3-fluorophenethylammonium bromide, 3-fluorophenethylammonium iodide, monoiodopiperazine, 9-octadecenylammonium iodide or octylammonium iodide.

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

3. The composite passivation layer modified inverse 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 inverse perovskite solar cell according to claim 1, characterized in that: After the composite passivation layer modifies the perovskite layer, the perovskite grain size is 0.2 to 2 μm.

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

6. The method for preparing a composite passivation layer modified inverse perovskite solar cell according to claim 5, characterized in that: The process of preparing the composite passivation layer includes: dissolving components a and b in a solvent and spin coating the components on the surface of the perovskite layer.

7. The method for preparing a composite passivation layer modified inverse perovskite solar cell according to claim 6, characterized in that: The concentration of the component a dissolved in the solvent is 0.1-10 mg / mL.

8. The method for preparing a composite passivation layer modified inverse perovskite solar cell according to claim 6, characterized in that: The concentration of the component b dissolved in the solvent is 0.1-8 mg / mL.

9. The method for preparing a composite passivation layer modified inverse perovskite solar cell according to claim 5, characterized in that: The perovskite layer is formed by spin coating, blade coating, spraying or inkjet printing.

10. The method for preparing a composite passivation layer modified inverse perovskite solar cell according to claim 5, characterized in that: The entire preparation process was carried out under air or N2 atmosphere.

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