CN109879307B

CN109879307B - Mesoporous SnO in perovskite solar cell2Preparation method of (1)

Info

Publication number: CN109879307B
Application number: CN201910204376.7A
Authority: CN
Inventors: 刘曰利; 李月双; 陈文�
Original assignee: Wuhan University of Technology WUT
Current assignee: Wuhan University of Technology WUT
Priority date: 2019-03-18
Filing date: 2019-03-18
Publication date: 2021-01-19
Anticipated expiration: 2039-03-18
Also published as: CN109879307A

Abstract

The invention discloses mesoporous SnO in a perovskite solar cell₂The mesoporous SnO₂The skeleton layer hasn-type conductivity. The invention adopts stannous oxalate (SnC)₂O₄) Adding sodium hydroxide (NaOH) into deionized water for full reaction, and adding oxidant H₂O₂Stirring to obtain tetravalent tin salt precursor solution; using CTAB as a template, adding ammonia water to adjust the pH, carrying out hydrothermal reaction, and carrying out post-treatment to obtain mesoporous SnO₂. Preparing mesoporous SnO by adopting spin-coating method₂When the film is used as a framework layer of a perovskite solar cell, the solar cell has good performances such as open-circuit voltage, short-circuit current density and the like.

Description

Mesoporous SnO in perovskite solar cell2Preparation method of (1)

Technical Field

The invention belongs to the technical field of perovskite type thin-film solar cells, and particularly relates to mesoporous SnO in a perovskite solar cell₂And a perovskite solar cell assembled by the method.

Background

Since the 21 st century, the population has grown dramatically and energy and environmental problems have become increasingly apparent. At present, people mainly consume non-renewable energy sources, such as fossil fuels such as coal, natural gas, petroleum and the like. In the future, human beings need a large amount of energy, so that the human beings are actively developing new energy.

The solar energy is clean, pollution-free, widely distributed and sufficient in energy, and is the research focus of the majority of researchers at present. The photovoltaic is a main object for developing solar energy, and mainly has the advantages of safety, cleanness, low cost and the like. The perovskite solar cell as a new solar cell has the advantages of high photoelectric conversion efficiency, simple preparation process, low manufacturing cost and the like, and the research on the perovskite solar cell is greatly advanced in a short time of six to seven years, so that the perovskite solar cell is predicted to be used as an efficient renewable energy device in the future and is likely to have wide application prospect.

The traditional mesoporous perovskite solar cell comprises a conductive substrate, a compact layer, a framework layer, a perovskite layer, a hole transport layer and a counter electrode. Wherein porous TiO is mainly adopted₂As the skeleton layer, the skeleton layer mainly functions as a support frame and charge transport, but TiO₂Poor stability of perovskite solar cells and TiO as electron transport layers₂High temperature annealing and the like are needed, and new replacement TiO needs to be searched₂An electron transport material. Tin dioxide is an n-type semiconductor materialThe material has a band gap (Eg) of 3.6eV, and has the characteristics of good flame retardance and electrical conductivity, infrared radiation reflection and adsorption, high stability and the like.

Disclosure of Invention

The invention aims to solve the problem of providing mesoporous SnO in a perovskite solar cell₂The preparation method of (a) mesoporous SnO₂The coating is coated on the surface of a compact layer of the perovskite solar cell and then used as a framework layer to assemble the perovskite solar cell, and the perovskite solar cell has good performance.

In order to achieve the purpose, the invention adopts the following technical scheme:

mesoporous SnO in perovskite solar cell₂The preparation method comprises the following steps:

(1) SnC₂O₄Adding NaOH into deionized water for full reaction, and then adding oxidant H₂O₂Stirring to prepare a precursor solution;

(2) subsequently, adding CTAB into the solution under vigorous stirring for uniform dispersion, and adding ammonia water to adjust the pH value to be alkaline;

(3) then carrying out hydrothermal reaction;

(4) post-treating the hydrothermal product to obtain mesoporous SnO₂。

According to the scheme, the mesoporous SnO₂White, uniform in shape distribution, uniform in particle size, regular in structure and porous in structure.

According to the scheme, SnC in the step (1)₂O₄The molar mass ratio of the NaOH to the NaOH is 1 (2-2.5).

According to the scheme, SnC in the step (1)₂O₄Amount of (A) and H₂O₂The molar mass ratio is 1: (2-5).

According to the scheme, CTAB and SnC are obtained in the step (2)₂O₄The mass ratio is 1 (2-3).

According to the scheme, the pH value in the step (2) is 7.5-10.

According to the scheme, the hydrothermal temperature in the step (3) is 150-.

According to the scheme, the post-treatment in the step (4) comprises the following steps: washing the hydrothermal reaction product, centrifuging for 5-12min at the rotation speed of 8000-12000rpm, drying in a vacuum drying oven, respectively washing the precipitate with deionized water and absolute ethyl alcohol, and then centrifuging to obtain a white pasty precipitate, and freeze-drying.

The mesoporous SnO prepared by the method₂Mesoporous SnO serving as perovskite solar cell₂The application method of the framework layer comprises the following steps: the mesoporous SnO prepared by the method₂Mixing with dispersant and water to obtain SnO₂Diluting the slurry with absolute ethyl alcohol according to a certain proportion, spin-coating the diluted slurry on the surface of a compact layer of the perovskite solar cell, and annealing to form SnO₂And (4) a framework layer.

According to the scheme, the compact layer of the perovskite solar cell is SnO₂A dense layer.

According to the scheme, the anhydrous ethanol and SnO are used₂The mass ratio of the slurry is (3-7) to 1.

According to the scheme, the annealing temperature is increased to 300 ℃ at the temperature increase rate of 5 ℃/min, and then the temperature is kept for 1 h.

A preparation method of a perovskite solar cell comprises the following steps:

(1) preparing a transparent conductive substrate;

(2) preparation of SnO on transparent conductive substrate₂A dense layer;

(3) mesoporous SnO in perovskite solar cell₂The mesoporous SnO prepared by the preparation method₂In SnO₂Preparation of SnO on a dense layer₂A framework layer;

(4) at SnO₂Preparing a perovskite light absorption layer on the framework layer;

(5) preparing a hole transport layer on the light absorbing layer;

(6) and preparing a metal electrode on the hole transport layer.

The invention adopts stannous oxalate (SnC)₂O₄) Adding sodium hydroxide (NaOH) into deionized water for full mixing reaction, and adding oxidant H₂O₂Stirring, using CTAB as template, regulating and controllingSynthesis of mesoporous SnO by hydrothermal reaction under pH alkaline condition₂The conductive material has the n-type conductivity, the preparation process is simple and controllable, the requirement on equipment is low, the reaction condition is mild, the energy consumption is low, the operability is strong, the conductive material is prepared only under the low-temperature hydrothermal condition, high-temperature roasting is not needed, and resources can be saved. The perovskite solar cell assembled by taking the perovskite solar cell as the transmission layer of the perovskite solar cell has high photoelectric conversion efficiency, and can improve the open-circuit voltage and the short-circuit current density.

Compared with the prior art, the invention has the beneficial effects that:

(1) the mesoporous SnO prepared under the alkaline condition₂The preparation method has the advantages of simple preparation process, low requirement on equipment, simple process, mild reaction conditions, low energy consumption, strong operability, high controllability and the like. Meanwhile, the invention only needs to be prepared under the condition of low-temperature hydrothermal and does not need high-temperature roasting. Resources can be saved.

(2) The raw materials adopted by the preparation method are cheap and easily available, and the obtained mesoporous SnO₂Has uniform and regular pore structure, pore size distribution and regular appearance.

(3) The mesoporous SnO prepared by the invention₂The absorption intensity of ultraviolet visible absorption is obviously improved; preparing mesoporous SnO by adopting spin-coating method₂When the film is used as a framework layer of a perovskite solar cell, the solar cell has good performance, wherein the open-circuit voltage is 1.01eV, and the short-circuit current density is 18.55mA/cm²The fill factor was 57.0%.

Drawings

FIG. 1 is SnO prepared by example 1₂XRD pattern of (a).

FIG. 2 is SnO prepared in example 1₂The upper image is magnified × 50.0K times, and the lower image is magnified × 10.0K times.

Fig. 3 is a schematic structural view of the mesoporous perovskite solar cell prepared in example 1.

FIG. 4 is a mesoporous SnO prepared in example 2₂SEM image of (d).

FIG. 5 is a mesoporous SnO prepared in example 3₂SEM image of (d).

FIG. 6 shows example 4Prepared mesoporous SnO₂SEM image of (d).

FIG. 7 is a mesoporous SnO prepared in example 5₂SEM image of (d).

FIG. 8 is a mesoporous SnO prepared in example 6₂SEM image of (d).

FIG. 9 is a graph showing the UV-VIS absorption spectra of examples 3 and 4.

Fig. 10 is a J-V plot of the mesoporous perovskite solar cell prepared in example 3.

Detailed Description

Example 1:

1) cleaning of the transparent conductive substrate:

washing the FTO conductive glass by using a detergent, deionized water and absolute ethyl alcohol in sequence, and then drying by using an air gun.

2) Preparing a compact layer:

0.5g of urea (CH) was added separately₄N₂O), 10. mu.L of thioglycolic acid (C)₂H₄O₂S) and 0.5mL of hydrochloric acid (HCl) 0.1038g of stannous chloride dihydrate (SnCl)₂·2H₂O) is added into 40mL deionized water and stirred for 10min at room temperature to prepare a precursor solution. And transferring the FTO glass and the precursor solution into a closed box for hydrothermal reaction, wherein the hydrothermal temperature is 70 ℃, the hydrothermal time is 3 hours, and then annealing is carried out for 1 hour at 180 ℃.

3) Preparation of the skeleton layer

2.07g SnC₂O₄After reacting with 0.80g NaOH in a beaker containing 30mL of deionized water, 0.68g of oxidant H was added₂O₂Stirring, then adding 1.01g of CTAB into the mixture under vigorous stirring for uniform dispersion, and adding ammonia water to adjust the pH to 7.6; the mixture was then transferred to a 80mL teflon-lined stainless steel autoclave for a hydrothermal reaction at 150 ℃ for 10 h. Washing the hydrothermal product, separating at 8000rpm for 12min to obtain white pasty precipitate, and freeze drying to obtain SnO₂And (3) powder. The obtained SnO₂Mixing the powder with dispersant and water to prepare SnO₂The slurry is diluted with absolute ethyl alcohol according to a certain proportion to obtain SnO₂Slurry, spin coating the obtained solutionCoating on the surface of the dense layer by an instrument, and annealing to form SnO₂And (4) a framework layer.

4) Preparing a perovskite light absorption layer:

firstly weighing 2mmol of PbI₂Placed in a three-necked flask, and 20mL of Octadecene (ODE) was added thereto while passing argon (Ar)₂) And (3) heating to 120 ℃ under the protection condition, respectively adding 2.5mL of Oleylamine (OLA) and Oleic Acid (OA), keeping the temperature for 30min, heating to 170 ℃, adding a certain amount of cesium oleate precursor solution (Cs-OA), and reacting for 5 s. Then washing and centrifuging to obtain the perovskite light absorption layer. Then the solution is coated on SnO in a spinning mode₂And (3) annealing the framework layer for 60min at the temperature of 300 ℃ at the rotating speed of 2000rpm for 20 s.

5) Preparing a hole transport layer:

20mg of Spiro-OMeTAD (2,2',7,7' -tetrakis [ N, N-bis (4-methoxyphenyl) amino ] -9,9' -spirobifluorene), 1 mL of methyl acetate, 14.4 to 28.8. mu.L of 4-t-butylpyridine, and 17.5 to 35. mu.L of a lithium bistrifluoromethylsulfinamide solution in acetonitrile (520mg/mL) were mixed and centrifuged. And spin-coating a hole transport layer on the perovskite light absorption layer by using the prepared hole transport material mixed solution at the rotating speed of 2000-4000rpm for 30 s.

6) Preparing an electrode:

and putting the sample with the well-coated hole transport layer into a template with an electrode pattern, and depositing a layer of gold counter electrode with the thickness of 50-80nm by using a vacuum evaporation method.

SnO prepared in this example₂The XRD spectrum and SEM image are respectively shown in figure 1 and figure 2, and the structure schematic diagram of the mesoporous perovskite solar cell is shown in figure 3. As seen in FIG. 1, SnO prepared in this example₂The main diffraction peaks (2 theta is 26.59 degrees, 33.89 degrees, 37.96 degrees and 51.79 degrees) of the nano-silver-tin-oxide-tin-₂The (110), (101), (200) and (211) crystal faces of the PDF card of (1) respectively correspond to the crystal faces of the light source. And no impurity peak, which shows that the crystal phase is good, and the obtained SnO₂Has tetragonal rutile structure and high purity. Has tetragonal rutile structure and high purity. As seen from the SEM image of FIG. 2, the mesoporous SnO prepared by the example₂The morphology is distributed uniformly, the mesoporous size is uniform, and the size is about 30-50 nm.

Example 2:

1) and cleaning the transparent conductive substrate. The same as in example 1.

2) And preparing the dense layer. The same as in example 1.

3) Preparing a framework layer:

2.07g SnC₂O₄After reacting with 0.80g NaOH in a beaker containing 30mL of deionized water, 1.05g of oxidant H was added₂O₂Stirring, then fully reacting 0.92g CTAB under vigorous stirring, and adding ammonia water to adjust the pH value to 8.2; the mixture was then transferred to a 80mL teflon-lined stainless steel autoclave for a hydrothermal reaction at 160 ℃ for 12 h. Washing the hydrothermal product, separating at 9000rpm for 10min to obtain white pasty precipitate, and freeze drying to obtain SnO₂And (3) powder. The obtained SnO₂Mixing the powder with a dispersant and water to prepare slurry.

Diluting SnO by absolute ethyl alcohol in a mass ratio of 3:1₂And (4) stirring and carrying out ultrasonic treatment on the slurry until the diluted slurry is completely and uniformly mixed. The mixed slurry was spin coated on the dense layer at 2000-4000rpm for 20 seconds. Then heating to 300 ℃ at the heating rate of 5 ℃/min, and then preserving heat for 1h to form SnO₂And (4) a framework layer.

4) And preparing the perovskite light absorption layer. The same as in example 1.

5) A hole transport layer is prepared. The same as in example 1.

6) And preparing an electrode. The same as in example 1.

Mesoporous SnO prepared in this example₂The SEM image is shown in FIG. 4.

Example 3:

1) and cleaning the transparent conductive substrate. The same as in example 1.

2) And preparing the dense layer. The same as in example 1.

3) Preparing a framework layer:

2.07g SnC₂O₄After reacting with 0.96g NaOH in a beaker containing 30mL of deionized water, 1.36g of oxidant H was added₂O₂Stirring, then fully reacting 0.85g CTAB under vigorous stirring, and adding ammonia water to adjust the pH value to 8.9; the mixture was then transferred to 80mLThe hydrothermal reaction was carried out at 170 ℃ for 13h in a Teflon-lined stainless steel autoclave. Washing the hydrothermal product, separating at 10000rpm for 6min to obtain white pasty precipitate, and freeze drying to obtain SnO₂And (3) powder. The obtained SnO₂Mixing the powder with a dispersant and water to prepare slurry.

Diluting SnO by absolute ethyl alcohol in a mass ratio of 4:1₂And (4) stirring and carrying out ultrasonic treatment on the slurry until the diluted slurry is completely and uniformly mixed. The mixed slurry was spin coated on the dense layer at 2000-4000rpm for 20 seconds. Then heating to 300 ℃ at the heating rate of 5 ℃/min, and then preserving heat for 1h to form SnO₂And (4) a framework layer.

5) A hole transport layer is prepared. The same as in example 1.

6) And preparing an electrode. The same as in example 1.

Mesoporous SnO prepared in this example₂The SEM image is shown in FIG. 5.

Example 4:

1) a transparent conductive substrate is prepared. The same as in example 1.

2) And preparing the dense layer. The same as in example 1.

3) Preparing a framework layer:

2.07g SnC₂O₄Adding 0.88g NaOH into a beaker containing 30mL deionized water, fully mixing and reacting, and adding 1.50g oxidant H₂O₂Stirring, then adding 0.72g CTAB into the mixture under vigorous stirring for uniform dispersion, adding ammonia to adjust pH to 9.0; the mixture was then transferred to a 80mL teflon-lined stainless steel autoclave for hydrothermal reaction at 170 ℃ for 15 h. Washing the hydrothermal product, separating at 11000rpm for 5min to obtain white pasty precipitate, and freeze drying to obtain SnO₂And (3) powder. The obtained SnO₂Mixing the powder with a dispersant and water to prepare slurry.

Diluting SnO by absolute ethyl alcohol in a mass ratio of 5:1₂And (4) stirring and carrying out ultrasonic treatment on the slurry until the diluted slurry is completely and uniformly mixed. The mixed slurry was spin coated on the dense layer at 2000-4000rpm for 20 seconds. Then 5 ℃The temperature is increased to 300 ℃ at the temperature rise rate of min and then is kept for 1h to form SnO₂And (4) a framework layer.

5) A hole transport layer is prepared. The same as in example 1.

6) And preparing an electrode. The same as in example 1.

Mesoporous SnO prepared in this example₂The SEM image is shown in FIG. 6.

Example 5:

1) a transparent conductive substrate is prepared. The same as in example 1.

2) And preparing the dense layer. The same as in example 1.

3) Preparing a framework layer:

2.07g SnC₂O₄After reacting sufficiently with 0.84g NaOH, 1.40g of an oxidizing agent H was added₂O₂Stirring, then adding 0.75g CTAB into the mixture under vigorous stirring for uniform dispersion, adding ammonia to adjust pH to 9.6; the mixture was then transferred to a 80mL teflon-lined stainless steel autoclave for a hydrothermal reaction at 180 ℃ for 15 h. Washing the hydrothermal product, separating at 12000rpm for 5min to obtain white pasty precipitate, and freeze drying to obtain SnO₂And (3) powder. The obtained SnO₂Mixing the powder with a dispersant and water to prepare slurry.

Diluting SnO by absolute ethyl alcohol in mass ratio of 6:1₂And (4) stirring and carrying out ultrasonic treatment on the slurry until the diluted slurry is completely and uniformly mixed. The mixed slurry was spin coated on the dense layer at 2000-4000rpm for 20 seconds. Then heating to 300 ℃ at the heating rate of 5 ℃/min, and then preserving heat for 1h to form SnO₂And (4) a framework layer.

5) A hole transport layer is prepared. The same as in example 1.

6) And preparing an electrode. The same as in example 1.

Mesoporous SnO prepared in this example₂The SEM image is shown in FIG. 7.

Example 6:

1) a transparent conductive substrate is prepared. The same as in example 1.

2) And preparing the dense layer. The same as in example 1.

3) Preparing a framework layer:

2.07g SnC₂O₄After mixing with 0.82g NaOH, 1.70g of oxidizing agent H was added₂O₂Stirring, then adding 0.80g CTAB into the mixture under vigorous stirring for uniform dispersion, and adding ammonia water to adjust the pH to 10; the mixture was then transferred to a 80mL teflon-lined stainless steel autoclave for a hydrothermal reaction at 180 ℃ for 15 h. Washing the hydrothermal product, separating at 12000rpm for 6min to obtain white pasty precipitate, and freeze drying to obtain SnO₂And (3) powder. The obtained SnO₂Mixing the powder with a dispersant and water to prepare slurry.

Diluting SnO by absolute ethyl alcohol in a mass ratio of 7:1₂And (4) stirring and carrying out ultrasonic treatment on the slurry until the diluted slurry is completely and uniformly mixed. The mixed slurry was spin coated on the dense layer at 2000-4000rpm for 20 seconds. Then heating to 300 ℃ at the heating rate of 5 ℃/min, and then preserving heat for 1h to form SnO₂And (4) a framework layer.

5) A hole transport layer is prepared. The same as in example 1.

6) And preparing an electrode. The same as in example 1.

Mesoporous SnO prepared in this example₂The SEM image is shown in FIG. 8.

Fig. 9 is a graph of the uv-vis absorption spectra of examples 3 and 4, which shows that examples 3 and 4 exhibit better light absorption characteristics in the uv region and the visible light region, and particularly, the absorption peak intensities are significantly different in the near uv region of <350 nm.

FIG. 10 is a J-V curve of example 3, which shows that mesoporous SnO prepared in example 3₂When the material is applied to a perovskite solar cell, the photoelectric conversion efficiency reaches 10.63 percent, wherein the open-circuit voltage reaches 1.01V, and the short-circuit current density reaches 18.55mA/cm²The fill factor reaches 57.0%. It can be seen that the mesoporous SnO prepared in example 3₂Application in perovskite solar cells, open circuit thereofThe voltage, the short-circuit current density and the filling factor are all higher.

Claims

1. Mesoporous SnO in perovskite solar cell₂The preparation method is characterized by comprising the following steps:

(1) SnC₂O₄Adding NaOH into deionized water for full reaction, and then adding oxidant H₂O₂Stirring to obtain precursor solution, wherein SnC₂O₄NaOH and H₂O₂The molar mass ratio is 1 (2-2.5): (2-5);

(2) subsequently, adding CTAB into the solution obtained in the step (1) under vigorous stirring for uniform dispersion, adding ammonia water to adjust the pH to be alkaline, wherein CTAB and SnC₂O₄The mass ratio is 1 (2-3);

(3) then carrying out hydrothermal reaction at the hydrothermal temperature of 150 ℃ and 180 ℃ for 10-15 hours;

(4) post-treating the hydrothermal reaction product to obtain mesoporous SnO₂。

2. Mesoporous SnO in perovskite solar cell according to claim 1₂Characterized in that the mesoporous SnO is₂White, uniform in shape distribution, uniform in particle size, regular in structure and porous in structure.

3. Mesoporous SnO in perovskite solar cell according to claim 1₂The production method of (2), wherein the pH in the step (2) is 7.5 to 10.

4. Mesoporous SnO in perovskite solar cell according to claim 1₂The preparation method is characterized in that the post-treatment in the step (4) is as follows: washing the hydrothermal reaction product, centrifuging for 5-12min at the rotation speed of 8000-12000rpm, drying in a vacuum drying oven, respectively washing the precipitate with deionized water and absolute ethyl alcohol, and centrifuging to obtain white pasty precipitate, and freeze-drying.

5. Mesoporous SnO prepared according to any one of claims 1 to 4₂Mesoporous SnO as perovskite solar cell₂The application of the framework layer is characterized in that the specific application method is as follows: mesoporous SnO prepared by a process according to any one of claims 1 to 4₂Mixing with dispersant and water to obtain SnO₂Diluting the slurry with absolute ethyl alcohol according to a certain proportion, spin-coating the diluted slurry on the surface of a compact layer of the perovskite solar cell, and annealing to form SnO₂And (4) a framework layer.

6. Mesoporous SnO according to claim 5₂Mesoporous SnO as perovskite solar cell₂The application of the framework layer is characterized in that the compact layer of the perovskite solar cell is SnO₂A dense layer; the anhydrous ethanol and the SnO₂The mass ratio of the slurry is (3-7) to 1; the annealing conditions are as follows: the temperature is raised to 300 ℃ at the temperature raising rate of 5 ℃/min, and then the temperature is maintained for 1 h.

7. A preparation method of a perovskite solar cell is characterized by comprising the following steps:

(1) preparing a transparent conductive substrate;

(2) preparation of SnO on transparent conductive substrate₂A dense layer;

(3) mesoporous SnO prepared by the method of any one of claims 1 to 4₂In SnO₂Preparation of SnO on a dense layer₂A framework layer;

(5) preparing a hole transport layer on the light absorbing layer;

(6) and preparing a metal electrode on the hole transport layer.