CN112151679B - A kind of nano crystal composite perovskite solar cell and its preparation method - Google Patents

Abstract

The invention discloses a nano-crystal composite perovskite solar cell and relates to the technical field of solar cells. It includes a conductive substrate, an electron transport layer, a light absorption layer, a hole transport layer and a metal electrode layer stacked in sequence from bottom to top; the light absorption layer includes a perovskite film, and the perovskite film contains Semiconductor oxide nanoparticles. The invention also discloses a preparation method of the nano crystal composite perovskite solar cell. The nanocrystalline composite perovskite solar cell provided by the invention has high photoelectric conversion efficiency, the photoelectric conversion efficiency is increased from 18% to more than 21%, and the performance and stability are obviously improved.

Description

A kind of nano crystal composite perovskite solar cell and its preparation method

technical field

The invention belongs to the technical field of solar cells, and relates to a nanocrystal composite perovskite solar cell and a preparation method thereof.

Background technique

Perovskite solar cells face problems such as carrier recombination and poor stability, which hinder their practical application. Therefore, how to further improve the efficiency and stability of perovskite cells has become a key issue that needs to be solved urgently. The polycrystalline perovskite film prepared by the low-temperature solution method contains lithium salts in the hole transport layer material, which will cause lithium ions to permeate at the grain boundaries in the perovskite film, resulting in carrier recombination, thereby reducing the performance of the battery.

Drawing lessons from the modification of perovskite solar cells by carbon quantum dots, introducing materials with strong carrier transport ability/high conductivity into the film is expected to promote the bulk transport process of carriers in the perovskite film, thereby improving the performance of perovskite solar cells. performance of solar cells. The grain boundary of the perovskite film is modified by using nanocrystalline materials with high hole mobility. The introduction of the material with high hole mobility into the film is expected to promote the bulk transport process of holes, and the nanocrystals introduced at the grain boundaries can also hinder lithium The penetration of ions in turn improves the long-term stability of perovskite cells. How to introduce materials with high hole migration into the perovskite film is a difficult point in obtaining high-performance solar cells with excellent long-term stability, which is exactly the technical problem to be solved by the present invention.

Contents of the invention

In order to solve the above-mentioned deficiencies, the present invention provides a nanocrystal composite perovskite solar cell and its preparation method. The solar cell has high hole mobility, high photoelectric conversion efficiency with excellent long-term stability, and simultaneously uses liquid phase Laser irradiation technology can directly prepare a size-controllable, monodisperse and stable oxide nanocrystal solution with high hole mobility, which can be directly put into use without complicated processes such as solvent/ligand exchange and centrifugal drying.

The first object of the present invention is to provide a nanocrystalline composite perovskite solar cell, which includes a conductive substrate, an electron transport layer, a light absorption layer, a hole transport layer and a metal electrode layer stacked sequentially from bottom to top;

The light absorbing layer includes a perovskite film, and the perovskite film contains semiconductor oxide nanoparticles.

Preferably, the semiconductor oxide particles are one of NiO, SmNiO ₃ , CuCrO ₃ and GaCrO ₃ .

More preferably, the light-absorbing layer is prepared according to the following steps:

First, the nanocrystalline colloidal solution is prepared by uniformly dispersing semiconductor oxide nanoparticles in an organic liquid medium and irradiating with a pulsed laser beam;

Secondly, spin-coat the perovskite precursor solution on the electron transport layer, and add the nanocrystal colloid solution during the spin-coating process, and then heat-treat at 100-150°C for 10-90 minutes to obtain the light-absorbing layer ;

Wherein, the dosage ratio of the perovskite precursor to the semiconductor oxide nanoparticles is 1moL: 0.037-4.76g.

More preferably, the concentration of the nanocrystal colloid solution is 0.01-0.5 mg/mL.

More preferably, the concentration of the perovskite precursor solution is 1.05˜1.35 mol/L.

More preferably, the organic liquid medium is one or more of ethyl formate, ethyl acetate, diethyl ether, diethyl ether.

More preferably, the perovskite precursor is AX and BX ₂ type compounds;

Wherein, A is one or more of CH ₃ NH ₃ ⁺ , HC(=NH)NH ₂ ⁺ , Cs ⁺ ;

B is Pb ²⁺ ;

X is one or more of halide ions.

More preferably, the wavelength of the pulsed laser is one of 1064 nm, 532 nm, and 355 nm, the energy is 50-1000 mJ/pulse, and the irradiation time is 2-30 min.

More preferably, the perovskite precursor solution is spin-coated on the electron transport layer by two-step spin coating at a low speed of 1000rpm/10s and a high speed of 4000rpm/30s, and the nanocrystals are added dropwise during the remaining 5-15s of high-speed spin coating colloidal solution.

The second object of the present invention provides a method for preparing a nanocrystalline composite perovskite solar cell, comprising the following steps:

Spin-coat the perovskite precursor solution on the conductive substrate covered with the electron transport layer, and add a certain amount of nanocrystal colloid solution while spin-coating, and form a nanocrystal composite perovskite film after heat treatment; On the crystalline composite perovskite thin film, the hole transport layer and the vapor-deposited metal electrode are sequentially spin-coated to obtain a nanocrystalline composite perovskite solar cell.

Compared with prior art, the beneficial effect of the present invention is:

The nanocrystal composite perovskite thin-film solar cell provided by the invention has high efficiency and good stability, and the photoelectric conversion efficiency increases from the basic 18% to over 21%, which improves the photoelectric conversion efficiency of the perovskite solar cell prepared by the low-temperature solution method , has a very high application prospect.

The invention adopts the liquid-phase pulsed laser irradiation technology to directly prepare a size-controllable, monodisperse and stable oxide nanocrystal solution with high hole mobility, without going through complex processes such as solvent/ligand exchange and centrifugal drying. When put into use, compared with the nano crystal solution prepared by the traditional preparation method, the whole preparation process is simple and the conditions are mild.

Description of drawings

FIG. 1 is the transmission spectrum of the SmNiO ₃ nanocrystals prepared in Example 2.

FIG. 2 is the current-voltage curves of the nanocrystal composite perovskite solar cell provided in Example 1 and the uncomposited original perovskite solar cell.

FIG. 3 is the current-voltage curves of the nanocrystal composite perovskite solar cell provided in Example 2 and the uncomposited original perovskite solar cell.

FIG. 4 is the current-voltage curves of the nanocrystal composite perovskite solar cell provided in Example 3 and the uncomposited original perovskite solar cell.

detailed description

In order to enable those skilled in the art to better understand that the technical solutions of the present invention can be implemented, the present invention will be further described below in conjunction with specific examples and accompanying drawings, but the given examples are not intended to limit the present invention.

Example 1

A nanocrystal composite perovskite solar cell, comprising a conductive substrate, an electron transport layer, a light absorption layer, a hole transport layer and a metal electrode layer stacked sequentially from bottom to top;

The light absorbing layer includes a perovskite film and semiconductor oxide nanoparticles contained in the perovskite film. The semiconductor oxide particles are NiO;

The specific preparation method of the above-mentioned nanocrystal composite perovskite solar cell is as follows:

S1. Under the assistance of ultrasound, irradiate 3mL of NiO-ethyl acetate suspension solvent with a concentration of 0.1mg/ml for 10min with a pulsed laser with a wavelength of 355nm and an energy of 100mJ to prepare a solution with a size of about 3nm and a concentration of 0.1mg /mL of NiO nanocrystalline ethyl acetate colloidal solution;

S2. Prepare a lead methylamine iodide (MAPbI ₃ ) perovskite precursor solution with a concentration of 1.25 mol/L in a nitrogen glove box: weigh 1.25 mmol of CH ₃ NH ₃ I and 1.25 mmol of PbI in a reagent bottle ₂ , and add 700 μL of dimethylformamide and 300 μL of dimethyl sulfoxide, stir the mixed solution at 60 ° C for 2 hours, and then filter it with an organic filter to obtain 1 mL of 1.25 mol/L calcium for the experiment Titanium ore precursor solution;

S3. Get 30 μ L of the perovskite precursor solution prepared in S2 and spin-coat it on the FTO conductive substrate covered with 70nm TiO2 electron transport layer, first spin-coat at low speed (1000rmp) for 10s, then spin-coat at high speed (5000rmp) for 30s, and When the remaining 10 seconds of high-speed spin coating, 200 μL of NiO nanocrystalline ethyl acetate colloid solution prepared by S1 was immediately added dropwise, and after the addition was completed, it was heat-treated at 100°C for 30 minutes to prepare a NiO nanocrystalline composite MAPbI ₃ perovskite film layer , the film has a uniform surface and a thickness of 550nm;

S4. Spin-coat the hole transport layer material Spiro-OMeTAD on the perovskite film layer prepared in S3, and then oxidize in air for 12 hours to obtain a hole transport layer with a thickness of 120 nm;

S5. Evaporating an Au electrode with an area of 0.1 cm ² and a thickness of 100 nm on the hole transport layer of S4 to obtain a NiO nanocrystal composite MAPbI ₃ perovskite solar cell;

The photoelectric conversion efficiency of the cell provided by this embodiment is 19.7%.

Example 2

A nanocrystal composite perovskite solar cell, comprising a conductive substrate, an electron transport layer, a light absorption layer, a hole transport layer and a metal electrode layer stacked sequentially from bottom to top;

The light absorbing layer includes a perovskite film and semiconductor oxide nanoparticles contained in the perovskite film. The semiconductor oxide particles are SmNiO ₃ ;

The specific preparation method of the above-mentioned nanocrystal composite perovskite solar cell is as follows:

S1. Under the assistance of ultrasound, irradiate 3mL of SmNiO ₃ -ether suspension solvent with a concentration of 0.03mg/ml for 10min with a pulsed laser with a wavelength of 1064nm and an energy of 1000mJ to prepare a mg/m L of SmNiO ₃ nanocrystal ether colloid solution; see Fig. 1 for the transmission spectrum of the SmNiO ₃ nanocrystals prepared by embodiment 2, from Fig. 1, it can be clearly seen that SmNiO ₃ nanocrystals are uniformly dispersed, and particles Uniform size;

S2. Prepare a lead methylamine iodide (MAPbI ₃ ) perovskite precursor solution with a concentration of 1.25 mol/L in a nitrogen glove box: weigh 1.25 mmol of CH ₃ NH ₃ I and 1.25 mmol of PbI in a reagent bottle ₂ , and add 700 μL of dimethylformamide and 300 μL of dimethyl sulfoxide, stir the mixed solution at 60 ° C for 2 hours, and then filter it with an organic filter to obtain 1 mL of 1.25 mol/L calcium for the experiment Titanium ore precursor solution;

S3. Get 30 μ L of the perovskite precursor solution prepared in S2 and spin-coat it on the FTO conductive substrate covered with a 70nm TiO2 electron transport layer. Spin-coat at a low speed (1000rmp) for 10s, then spin-coat at a high speed (5000rmp) for 30s, and In the remaining 10s of high-speed spin coating, 200 μL of the SmNiO ₃ nanocrystalline ether colloid solution prepared in S1 was immediately added dropwise, and after the addition was completed, it was heat-treated at 100°C for 30 min to prepare a SmNiO ₃ nanocrystalline composite MAPbI ₃ perovskite film. layer, the film has a uniform surface and a thickness of 550nm;

S4. Spin-coat the hole transport material Spiro-OMeTAD on the perovskite film layer prepared in S3, and then oxidize in air for 12 hours to obtain a hole transport layer with a thickness of 120 nm;

S5. Evaporating an Au electrode with an area of 0.1 cm ² and a thickness of 100 nm on the hole transport layer of S4 to obtain a MAPbI ₃ perovskite solar cell composed of SmNiO ₃ nanocrystals.

The photoelectric conversion efficiency of the cell provided by this embodiment is 21.3%.

Example 3

A nanocrystal composite perovskite solar cell, comprising a conductive substrate, an electron transport layer, a light absorption layer, a hole transport layer and a metal electrode layer stacked sequentially from bottom to top;

The light absorbing layer includes a perovskite film and semiconductor oxide nanoparticles contained in the perovskite film. The semiconductor oxide particles are CuCrO ₃ ;

The specific preparation method of the above-mentioned nanocrystal composite perovskite solar cell is as follows:

S1. With the assistance of ultrasound, irradiate 3mL of CuCrO ₃ -ethyl acetate suspension solvent with a concentration of 0.03mg/ml with a pulsed laser with a wavelength of 355nm and an energy of 100mJ for 10min to prepare a mg/mL CuCrO ₃ nanocrystalline ethyl acetate colloidal solution;

S2. Prepare a lead methylamine iodide (MAPbI ₃ ) perovskite precursor solution with a concentration of 1.2 mol/L in a nitrogen glove box: weigh 1.2 mmol of CH ₃ NH ₃ I and 1.2 mmol of PbI in a reagent bottle ₂ , and add 700 μL of dimethylformamide and 300 μL of dimethyl sulfoxide, stir the mixed solution at 60 ° C for 2 hours, and then filter it with an organic filter to obtain 1 mL of 1.2 mol/L calcium for the experiment Titanium ore precursor solution;

S3. Get 30 μ L of the perovskite precursor solution prepared in S2 and spin-coat it on the FTO conductive substrate covered with a 70nm TiO2 electron transport layer. Spin-coat at a low speed (1000rmp) for 10s, then spin-coat at a high speed (5000rmp) for 30s, and In the remaining 10s of high-speed spin coating, 200 μL of the CuCrO ₃ nanocrystalline ethyl acetate colloid solution prepared in S1 was immediately added dropwise, and after the addition was completed, it was heat-treated at 100°C for 60 min to prepare the CuCrO ₃ nanocrystalline composite MAPbI ₃ perovskite Mine film layer, the film surface is uniform and smooth, and the thickness is 550nm;

S4. Spin-coat the hole transport material Spiro-OMeTAD on the perovskite film layer prepared in S3, and then oxidize in air for 12 hours to obtain a hole transport layer with a thickness of 120 nm;

S5. Evaporating an Au electrode with an area of 0.1 cm ² and a thickness of 100 nm on the hole transport layer of S4 to obtain a CuCrO ₃ nanocrystalline composite MAPbI ₃ perovskite solar cell.

The photoelectric conversion efficiency of the cell provided by this embodiment is 20.7%.

In order to illustrate a kind of nanocrystal composite perovskite solar cell provided by the present invention and its preparation method, the performance parameters of the nanocrystal composite perovskite solar cell prepared in Examples 1 to 3 are shown in Tables 1 to 3; and Examples The current-voltage curves of nanocrystal-composited perovskite solar cells provided in 1-3, and the related performance of uncomposited original perovskite solar cells are used as the original control group, as shown in Figures 2-4.

Table 1: Performance parameters of the battery prepared in Example 1

Table 2: Performance parameters of the battery prepared in Example 2

Table 3: Performance parameters of the battery prepared in Example 3

From Tables 1 to 3 and Figures 2 to 4, it can be seen that the open circuit voltage, short circuit current and fill factor of the nanocrystal composite perovskite solar cells have been significantly improved compared with the original perovskite solar cells, which is due to the nanocrystal composite The high hole rate nanocrystals in the perovskite film promote the extraction of holes in the perovskite film and facilitate the transport of holes generated in the perovskite film to the hole transport layer, thus combining nanocrystals with perovskite solar energy The photoelectric conversion efficiency of the cell was improved from 18% to more than 21% for the pristine perovskite solar cell.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (8)

1. A nanocrystal composite perovskite solar cell, characterized in that, comprises a conductive substrate, an electron transport layer, a light absorption layer, a hole transport layer and a metal electrode layer which are stacked successively from bottom to top; The light-absorbing layer includes a perovskite film, and semiconductor oxide nanoparticles contained in the perovskite film; The semiconductor oxide nanoparticles are one of NiO, SmNiO ₃ , CuCrO ₃ , GaCrO ₃ ; The light absorbing layer is prepared according to the following steps: First, the nanocrystalline colloidal solution is prepared by uniformly dispersing semiconductor oxide nanoparticles in an organic liquid medium and irradiating with a pulsed laser beam; Secondly, spin-coat the perovskite precursor solution on the electron transport layer, and add the nanocrystal colloid solution during the spin-coating process, and then heat-treat at 100-150°C for 10-90 minutes to obtain the light-absorbing layer ; Wherein, the dosage ratio of the perovskite precursor to the semiconductor oxide nanoparticles is 1moL: 0.037-4.76g. 2 . The nanocrystal composite perovskite solar cell according to claim 1 , wherein the concentration of the nanocrystal colloid solution is 0.01˜0.5 mg/mL. 3 . The nanocrystal composite perovskite solar cell according to claim 1 , wherein the concentration of the perovskite precursor solution is 1.05˜1.35 mol/L. 4 . The nanocrystal composite perovskite solar cell according to claim 1 , wherein the organic liquid medium is one or more of ethyl formate, ethyl acetate, diethyl ether, and ethylene glycol. 5. The nanocrystal composite perovskite solar cell according to claim 1, wherein the perovskite precursor is AX and BX ₂ type compounds; Wherein, A is one or more of CH ₃ NH ₃ ⁺ , HC(=NH)NH ₂ ⁺ , Cs ⁺ ; B is Pb ²⁺ ; X is one or more of halide ions. 6. The nanocrystal composite perovskite solar cell according to claim 1, characterized in that, the wavelength of the pulsed laser is one of 1064nm, 532nm, and 355nm, the energy is 50-1000mJ/pulse, and the irradiation time 2 to 30 minutes. 7. The nanocrystal composite perovskite solar cell according to claim 1, characterized in that, spin-coating the perovskite precursor solution on the electron transport layer adopts two-step spinning at a low speed of 1000rpm/10s and a high speed of 4000rpm/30s. Coating, and dropwise adding the nanocrystal colloid solution during the remaining 5-15s of high-speed spin coating. 8. a preparation method of the nano-crystal composite perovskite solar cell as claimed in claim 1, is characterized in that, comprises the following steps: Spin-coat the perovskite precursor solution on the conductive substrate covered with the electron transport layer, and add a certain amount of nanocrystal colloid solution while spin-coating, and form a nanocrystal composite perovskite film after heat treatment; On the crystalline composite perovskite thin film, the hole transport layer and the vapor-deposited metal electrode are sequentially spin-coated to obtain a nanocrystalline composite perovskite solar cell.

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