CN112186109B - Perovskite thin film preparation method, perovskite thin film and perovskite solar cell - Google Patents

Abstract

The invention discloses a preparation method of a perovskite film, which comprises the following steps: 1) Spin-coating a perovskite solution onto a semiconductor layer of a substrate with the semiconductor layer, wherein the perovskite solution is one or more of DMF, DMSO and gamma-GBL; 2) Dropping an inverse solvent before spin coating is finished; 3) And after spin coating, annealing the substrate in a gas environment with the pressure of 0.1-10Mpa at 80-120 ℃ for 5-60 minutes to prepare the perovskite film. The perovskite thin film prepared by the method has good stability and improved photoelectric performance, and is suitable for being used as a material of a perovskite solar cell.

Description

Preparation method of perovskite film, perovskite film and perovskite solar cell

Technical field

The present invention relates to the technical field of solar cells, and in particular to a method for preparing a perovskite film, the prepared perovskite film and a perovskite solar cell.

Background technique

At present, the method for preparing dense perovskite films is usually to first prepare a perovskite solution, then drop it on the substrate and spin-coat it. During the spinning process, drop in anti-solvent (anti-solvent), such as toluene, isopropyl Alcohol, ether, etc. can induce rapid crystallization of perovskite, thereby producing a dense perovskite film.

Although this method can produce a dense perovskite film, it also has the following problems: (1) The film has poor stability and is easily decomposed by the action of water and oxygen in the atmospheric environment. Even under packaging conditions, It is also prone to decomposition at high temperatures; (2) The film has a small grain size and a large defect density, which is not conducive to the improvement of photoelectric conversion efficiency. The above two factors limit the use of inverse solvent to rapidly induce perovskite crystallization film formation technology to prepare large-grained perovskite films. Therefore, the above technology still needs to be improved and developed.

Contents of the invention

In order to solve the problems that the perovskite film prepared by the above-mentioned prior art has poor stability, small crystal grains and high defect density, which is not conducive to the improvement of photoelectric conversion efficiency, the present invention provides a preparation method of a perovskite film, a perovskite film and a calcium Titanium ore solar cells.

The preparation method of the perovskite film of the present invention includes the following steps:

1). Spin-coat the perovskite solution onto the semiconductor layer of the substrate having the semiconductor layer. The solvent of the perovskite solution is dimethylformamide (DMF), dimethyl sulfoxide (DMSO), γ -One or more types of butyrolactone (γ-GBL);

2) Drop in the reverse solvent before the end of spin coating;

3) After the spin coating is completed, anneal the substrate at 80-120°C for 5-60 minutes in a gas environment with a pressure of 0.1-10Mpa to prepare a perovskite film.

By annealing in the above-mentioned high-pressure gas environment, the grain size of the film is effectively increased, the defect density is effectively reduced, and the photoelectric performance of the film is improved; in addition, the stability of the film annealed in the high-pressure gas environment is also improved.

In step 1), the concentration of the perovskite solution is 1-1.5 mol/L.

In step 1), the substrate is an FTO or ITO transparent electrode, the semiconductor layer is one of TiO ₂ , SnO ₂ , ZnO, PEDOT: PSS, and NiO, and the thickness of the semiconductor layer is 30-50 nm.

In step 2), the reverse solvent is one or more of isopropyl alcohol, ether, toluene, and chloroform, and the dripping of the reverse solvent is performed 5-15 seconds before the end of spin coating.

In step 3), the gas is one or more of nitrogen, argon, helium, and air.

In step 3), the temperature rise rate of annealing is 5-15°C/min.

The present invention provides a perovskite film, which is prepared using the above preparation method of the perovskite film.

The present invention provides a perovskite solar cell, which contains the above-mentioned perovskite film.

Beneficial effects: In the process of using perovskite solution to prepare the film, the present invention uses high-pressure gas as the pressure medium, and anneals the film in a high-pressure environment, which can effectively increase the grain size and reduce the defect density. Improve the quality of the perovskite film and improve the stability of the film; it also improves the photoelectric properties of the film, that is, improves the efficiency of perovskite solar cells, in which the filling factor and short-circuit current of the device performance parameters are significantly improved.

Description of drawings

Figure 1 is an atomic force microscope image of the perovskite film of the present invention;

Figure 2 is a graph showing the photoluminescence intensity and the average grain size of the film of the perovskite film of the present invention;

Figure 3 is a j-v curve diagram of the perovskite film of the present invention;

Figure 4 is a diagram showing various parameters of a battery device using the perovskite film of the present invention;

Figure 5 is an x-ray diffraction pattern of the perovskite film of the present invention.

Detailed ways

The technical solutions of the present invention will be described in detail below through examples, but the protection scope of the present invention is not limited to the examples.

Example 1

1). First, the perovskite (CH ₃ NH ₃ PbI ₃ ) solution is spin-coated onto the 40nm-thick TiO ₂ semiconductor layer (dense layer) on the FTO conductive glass; the concentration of the perovskite solution is 1.4 mol/L, the solvent is a mixed solvent of DMF and DMSO, the volume ratio of DMF and DMSO is 5:1;

2) Then drop in isopropyl alcohol and ether as the reverse solvent 10 seconds before the spin coating stops. The volume fraction of isopropyl alcohol is 0.1%;

3) After the spin coating is completed, place the substrate into a high-pressure tube furnace (OTF-1200X-HP-55, Hefei Kejing Materials Technology Co., Ltd., the same below), and then fill it with argon gas to bring the pressure to 2MPa. , and then heated to 100°C at a heating rate of 10°C/min and maintained for 30 minutes to form a perovskite film 1.

The perovskite solar cell 1 is manufactured by a conventional method using the perovskite thin film 1 .

Example 2

1). First, spin-coat the perovskite solution onto the 40nm-thick TiO ₂ semiconductor layer (dense layer) on the FTO conductive glass; the concentration of the perovskite solution is 1.4mol/L, and the solvent is DMF and DMSO mixed solvent, the volume ratio of DMF and DMSO is 5:1;

2) Then drop in isopropyl alcohol and ether as the reverse solvent 10 seconds before the spin coating stops. The volume fraction of isopropyl alcohol is 0.1%;

3) After the spin coating is completed, place the substrate into a high-pressure tube furnace, then fill it with argon gas to reach a pressure of 4MPa, and then heat it to 100°C at a heating rate of 10°C/min and maintain it for 30 minutes. Preparation of perovskite film 2.

A perovskite solar cell 2 is manufactured using a conventional method using the perovskite thin film 2 .

Example 3

1). First, spin-coat the perovskite solution onto the 40nm-thick TiO ₂ semiconductor layer (dense layer) on the FTO conductive glass; the concentration of the perovskite solution is 1.4mol/L, and the solvent is DMF and DMSO mixed solvent, the volume ratio of DMF and DMSO is 5:1;

2) Then drop in isopropyl alcohol and ether as the reverse solvent 10 seconds before the spin coating stops. The volume fraction of isopropyl alcohol is 0.1%;

3) After the spin coating is completed, place the substrate into a high-pressure tube furnace, then fill it with argon gas to reach a pressure of 6MPa, and then heat it to 100°C at a heating rate of 10°C/min and maintain it for 30 minutes. Preparation of perovskite film 3.

A perovskite solar cell 3 is manufactured using a conventional method using the perovskite thin film 3 .

Example 4

1). First, spin-coat the perovskite solution onto the 40nm-thick TiO ₂ semiconductor layer (dense layer) on the FTO conductive glass; the concentration of the perovskite solution is 1.4mol/L, and the solvent is DMF and DMSO mixed solvent, the volume ratio of DMF and DMSO is 5:1;

2) Then drop in isopropyl alcohol and ether as the reverse solvent 10 seconds before the spin coating stops. The volume fraction of isopropyl alcohol is 0.1%;

3) After the spin coating is completed, place the substrate into a high-pressure tube furnace, then fill it with argon gas to reach a pressure of 8MPa, and then heat it to 100°C at a heating rate of 10°C/min and maintain it for 30 minutes. Perovskite film 4 is produced.

A perovskite solar cell 4 is manufactured using a conventional method using the perovskite thin film 4 .

Example 5

1). First, spin-coat the perovskite solution onto the 40nm-thick TiO ₂ semiconductor layer (dense layer) on the FTO conductive glass; the concentration of the perovskite solution is 1.4mol/L, and the solvent is DMF and DMSO mixed solvent, the volume ratio of DMF and DMSO is 5:1;

2) Then drop in isopropyl alcohol and ether as the reverse solvent 10 seconds before the spin coating stops. The volume fraction of isopropyl alcohol is 0.1%;

3) After the spin coating is completed, place the substrate into a high-pressure tube furnace, then fill it with argon gas to reach a pressure of 10MPa, and then heat it to 100°C at a heating rate of 10°C/min and maintain it for 30 minutes. Perovskite film 5 is produced.

A perovskite solar cell 5 is manufactured using a conventional method using the perovskite thin film 5 .

Performance tests were performed on the perovskite films and perovskite solar cells prepared in the above embodiments 1, 2, 3, 4 and 5 respectively.

Test conditions: Use a 3NTEGRA (NT-MDT) atomic force microscope to photograph the surface morphology of the film, use a LabRAM HREvolution (Horiba) spectrometer to test the photoluminescence spectrum, and use a Bruker (D8 ADVANCE) x-ray diffractometer to perform in-situ XRD testing. The simulated lighting conditions of the Newport Oriel Solar (3 A Class AAA, 94023 A) solar simulator are AM 1.5G, 1000 mW/cm ² , and the jv curve is measured using a Keithly 2400 digital original meter. All tests are conducted in an air environment. The measured results are shown in Table 1 and Figures 1-5.

Table 1

Annealing air pressure Average grain size (nm) PL luminescence intensity (a.u.) Phase change temperature (℃) Example 1 2MPa 833 8000 40 Example 2 4MPa 1083 22500 45 Example 3 6MPa 1182 25000 55 Example 4 8MPa 825 16000 55 Example 5 10MPa 706 5000 60

Figure 1 is an atomic force microscope image of the perovskite film of the present invention. It can be seen from the figure that the surface grain size of the film annealed under pressure environment is significantly larger than that under conventional pressure (0.1MPa), which is beneficial to improving the efficiency of battery devices.

Figure 2 is a graph showing the photoluminescence (PL) intensity and the average grain size of the film of the perovskite film of the present invention. Generally speaking, the greater the photoluminescence intensity, the fewer film defects. It can be seen from the figure that as the pressure changes, the luminescence intensity first increases and then decreases, reaching a maximum value at 6MPa, while the conventional pressure (0.1MPa ) is the smallest. In addition, the average grain size of the film is also shown in the figure, and its trend is consistent with photoluminescence.

Figure 3 is a j-v curve diagram of the perovskite film of the present invention. This figure shows the performance of solar cells prepared from thin films annealed under different pressures. It can be seen from the figure that the solar cell prepared by annealing at 6MPa has the highest efficiency.

Figure 4 is a diagram showing various parameters of a battery device using the perovskite film of the present invention. This figure represents the performance parameters of solar cells prepared by annealing under different pressures.

Figure 5 is an x-ray diffraction pattern of the perovskite film of the present invention. This figure shows that when annealed in a pressure environment, the organic perovskite film MAPbI ₃ can withstand a high temperature of 300 ^° C without decomposing, which is much higher than the temperature that the film can withstand under normal pressure.

As stated above, although the present invention has been shown and described with reference to specific preferred embodiments, this is not to be construed as limiting the invention itself. Various changes may be made in form and details without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (6)

1. The preparation method of the perovskite thin film is characterized by comprising the following steps of:

1) Spin-coating a perovskite solution onto a semiconductor layer of a substrate with the semiconductor layer, wherein the perovskite solution is one or more of DMF, DMSO and gamma-GBL;

2) Dropping an inverse solvent before spin coating is finished;

3) Annealing the substrate in a gas environment with the pressure of 2-10MPa at 80-120 ℃ for 5-60 minutes after spin coating is finished to prepare a perovskite film;

in the step 2), the inversion solvent is one or more of isopropanol, diethyl ether and chloroform, and the dripping of the inversion solvent is carried out 5-15 seconds before the spin coating is finished;

in the step 3), the temperature rising speed of the annealing is 5-15 ℃/min.

2. The method for producing a perovskite thin film according to claim 1, wherein in step 1), the concentration of the perovskite solution is 1 to 1.5mol/L.

3. The method of claim 1, wherein in step 1), the substrate is an FTO or ITO transparent electrode, and the semiconductor layer is TiO ₂ 、SnO ₂ ZnO, PEDOT: the thickness of the semiconductor layer is 30-50nm, which is one of PSS and NiO.

4. The method for producing a perovskite thin film according to claim 1, wherein in the step 3), the gas is one or more of nitrogen, argon, helium, and air.

5. A perovskite thin film, characterized in that it is produced by using the production method of a perovskite thin film according to any one of claims 1 to 4.

6. A perovskite solar cell comprising the perovskite thin film of claim 5.