CN112420929A

CN112420929A - Perovskite solar cell with cesium-doped tin dioxide thin film as electron transport layer and preparation method thereof

Info

Publication number: CN112420929A
Application number: CN202011419664.3A
Authority: CN
Inventors: 罗云荣; 孙佳琪; 王若莹; 魏强; 刘婧瑜; 祁颖
Original assignee: Hunan Normal University
Current assignee: Hunan Normal University
Priority date: 2020-12-08
Filing date: 2020-12-08
Publication date: 2021-02-26

Abstract

The invention discloses a perovskite solar cell taking a cesium-doped tin dioxide thin film as an electron transport layer and a preparation method thereof, and is characterized in that the structure of the solar cell sequentially comprises the following components from bottom to top: the electron-conducting device comprises a transparent conducting substrate 1, an electron-transporting layer 2, a perovskite light-absorbing layer 3, a silicon carbide-silicon dioxide nano polymer layer 4 and a metal electrode 5. The invention has the advantages that: firstly, the cesium-doped tin dioxide film is used as an electron transport layer, has a more compact surface and a wider energy gap, can effectively inhibit the recombination of carriers, and increases the short-circuit current and open-circuit voltage of the perovskite solar cell; and secondly, the silicon carbide-silicon dioxide nano polymer can effectively improve the utilization rate of carriers, passivate the surface defects of a perovskite light absorption layer, reduce the loss of reflected light, increase light absorption and photocurrent, and improve the photoelectric conversion efficiency of the solar cell.

Description

Perovskite solar cell with cesium-doped tin dioxide thin film as electron transport layer and preparation method thereof

Technical Field

The invention belongs to the field of new energy, and particularly relates to a perovskite solar cell taking a cesium-doped tin dioxide thin film as an electron transport layer and a preparation method thereof.

Background

With the progress of science and technology, the living standard of people is continuously improved, and the requirement of human on energy is rapidly increased, so that the utilization of solar energy is more and more emphasized, and the search for a high-efficiency and stable solar cell becomes the struggle target of researchers. However, the perovskite solar cell is widely concerned due to its excellent photovoltaic characteristics and great commercial value, but the poor stability of the perovskite solar cell is a technical bottleneck that restricts its wide application. The stability of the perovskite material is affected not only by the instability of the perovskite material, but also by the fact that the commonly used hole transport material is susceptible to the movement of surrounding ions and is not stable enough in air. And the commonly used hole transport materials are expensive and the repeatability of the experimental operation process is poor.

Research shows that under the condition of illumination, the perovskite thin film of the perovskite solar cell can absorb photons to generate electron-hole pairs, and the perovskite thin film has good electron and hole transmission capability, so that a theoretical basis is provided for the perovskite solar cell without a hole transmission layer. However, without the hole transport layer, the perovskite thin film is directly contacted with the metal electrode, which has interface defects, causing serious carrier recombination, and also has the problems of high potential barrier, wide depletion layer and the like, thereby greatly reducing the efficiency of the perovskite solar cell. In order to solve this problem, many barrier layers are currently used, mainly including metal oxides such as aluminum oxide and zirconium oxide, and the introduction of these oxides can reduce interface recombination and block diffusion of electrons to the metal electrode. The silicon carbide-silicon dioxide nano polymer adopted by the method not only can reduce interface recombination and prevent electrons from diffusing to a metal electrode, but also can passivate the surface defect of a perovskite light absorption layer, improve the utilization rate of a photon-generated carrier, reduce the loss of reflected light and increase the light absorption, and the introduction of the silicon carbide-silicon dioxide nano polymer can further improve the photocurrent and the photoelectric conversion efficiency of a solar cell because the band gap difference between the silicon carbide and crystalline silicon is small.

In addition, the research on the improvement of the electron transport layer material is also of great significance for improving the photoelectric conversion efficiency of the device. The electron transport layer in the perovskite solar cell is generally made of titanium dioxide (TiO) which is a traditional electron transport layer material₂) However, compared to titanium dioxide, tin dioxide (SnO)₂) Has wider optical band gap (3.8 eV), larger electron mobility, more energy level matching with perovskite and can be prepared under low temperature condition. Researches show that the cesium (Cs) element is doped in the tin dioxide, so that the transmission and collection capacity of carriers in the tin dioxide film can be remarkably improved, and the short-circuit current of the perovskite solar cell is increased. Furthermore, after doping with cesium, the fermi level of the tin dioxide is improved, thereby increasing the open circuit voltage of the perovskite solar cell. Researches show that compared with the cesium-doped tin dioxide doped with other elements such as zinc and the like, the cesium-doped tin dioxide has a more compact surface, can generate larger carrier concentration and transmission rate, can improve the forbidden bandwidth of the tin dioxide, and effectively inhibits the recombination reaction of photon-generated carriers. In addition, it has also been reported that doping a rare earth element, such as lanthanum, in a tin dioxide thin film can significantly improve the stability of the doped host, but the experimental process is complicated, the temperature required for the experiment is high, and the preparation time is long. The cesium element doping experiment in the tin dioxide film is easy to realize, the required temperature is low, the preparation process is simple, and the cost can be saved.

Disclosure of Invention

In summary, in order to reduce the processes, reduce the cost and improve the stability and the photoelectric conversion efficiency of the perovskite solar cell, the invention provides the perovskite solar cell taking the cesium-doped tin dioxide thin film as the electron transport layer and the preparation method thereof, and the perovskite solar cell is characterized in that the structure of the solar cell sequentially comprises a transparent conductive substrate, the electron transport layer, the perovskite light absorption layer, a silicon carbide-silicon dioxide nano polymer layer and a metal electrode from bottom to top. The transparent conductive substrate is FTO conductive glass or ITO conductive glass or ZTO conductive glass or graphene; the electron transport layer is a cesium-doped tin dioxide film; the perovskite light absorption layer is a perovskite thin film; the silicon carbide-silicon dioxide nano polymer layer is a silicon carbide-silicon dioxide nano polymer. The preparation process of the perovskite solar cell comprises the following steps: firstly, taking a clean and dry transparent conductive substrate; then, preparing a cesium-doped tin dioxide film on the transparent conductive substrate by using a spin-coating method, a solution deposition method or a chemical water bath method; then, depositing a perovskite thin film on the cesium-doped tin dioxide thin film by using a spin coating method or a vapor deposition method or an evaporation method; then, depositing a silicon carbide-silicon dioxide nano polymer on the perovskite film by using a spin coating method or a chemical vapor deposition method; and finally, depositing a metal electrode on the silicon carbide-silicon dioxide nano polymer by adopting a vacuum evaporation method or a screen printing method to obtain the solar cell. The invention has the advantages that: firstly, the cesium-doped tin dioxide film is used as an electron transport layer, has a more compact surface and a wider energy gap, can effectively inhibit the recombination of carriers, and increases the short-circuit current and open-circuit voltage of the perovskite solar cell; and secondly, the silicon carbide-silicon dioxide nano polymer can effectively improve the utilization rate of carriers, passivate the surface defects of a perovskite light absorption layer, reduce the loss of reflected light, increase light absorption and photocurrent, and improve the photoelectric conversion efficiency of the solar cell.

Drawings

FIG. 1 is a schematic layer structure diagram of a perovskite solar cell using a cesium-doped tin dioxide thin film as an electron transport layer according to the present invention.

The reference numbers illustrate:

1- - -a transparent conductive substrate;

2- - -an electron transport layer;

3-perovskite light absorption layer;

4- - -a silicon carbide-silica nano-polymer layer;

5- -metal electrode.

Detailed Description

The invention will be further described with reference to the following drawings and specific examples, but the invention is not limited to the examples.

The invention has a structure shown in the attached drawing, and comprises a transparent conductive substrate 1, an electron transmission layer 2, a perovskite light absorption layer 3, a silicon carbide-silicon dioxide nano polymer layer 4 and a metal electrode 5 which are sequentially distributed from bottom to top.

The first embodiment is as follows: firstly, taking a piece of clean and dry ZTO conductive glass, and preparing a cesium-doped tin dioxide film on the ZTO conductive glass by using a solution deposition method; then, depositing a perovskite thin film on the cesium-doped tin dioxide thin film by using a spin coating method; then, depositing a silicon carbide-silicon dioxide nano polymer on the perovskite film by using a spin-coating method; and finally, depositing a metal electrode on the silicon carbide-silicon dioxide nano polymer by adopting a vacuum evaporation method to obtain the solar cell.

Example two: firstly, taking a piece of clean and dry FTO conductive glass, and then preparing a cesium-doped tin dioxide film on the FTO conductive glass by using a solution deposition method; then depositing a perovskite thin film on the cesium-doped tin dioxide thin film by using a vapor deposition method; then, depositing a silicon carbide-silicon dioxide nano polymer on the perovskite film by using a chemical vapor deposition method; and finally, depositing a metal electrode on the silicon carbide-silicon dioxide nano polymer by adopting a screen printing method to obtain the solar cell.

Example three: firstly, taking a piece of clean and dry ITO conductive glass, and then preparing a cesium-doped tin dioxide film on the ITO conductive glass by using a spin-coating method; then depositing a perovskite thin film on the cesium-doped tin dioxide thin film by an evaporation method; then, depositing a silicon carbide-silicon dioxide nano polymer on the perovskite film by using a spin-coating method; and finally, depositing a metal electrode on the silicon carbide-silicon dioxide nano polymer by adopting a screen printing method to obtain the solar cell.

Claims

1. The perovskite solar cell with the cesium-doped tin dioxide thin film as the electron transport layer and the preparation method thereof are characterized in that the structure of the solar cell sequentially comprises the following components from bottom to top: the electron transport layer is formed on the transparent conducting substrate, the perovskite light absorption layer is formed on the perovskite light absorption layer, the silicon carbide-silicon dioxide nano polymer layer is formed on the perovskite light absorption layer, and the metal electrode is formed on the silicon carbide-silicon dioxide nano polymer layer.

2. The solar cell of claim 1, wherein the transparent conductive substrate is FTO conductive glass or ITO conductive glass or ZTO conductive glass or graphene.

3. The solar cell of claim 1, wherein the electron transport layer is a cesium doped tin dioxide thin film.

4. The solar cell of claim 1, wherein the perovskite light absorbing layer is a perovskite thin film.

5. The solar cell of claim 1, wherein the silicon carbide-silica nano-polymer layer is a silicon carbide-silica nano-polymer.

6. A method of manufacturing a solar cell according to claim 1, wherein first, a clean and dry transparent conductive substrate is taken; then, preparing a cesium-doped tin dioxide film on the transparent conductive substrate by using a spin-coating method, a solution deposition method or a chemical water bath method; then, depositing a perovskite thin film on the cesium-doped tin dioxide thin film by using a spin coating method or a vapor deposition method or an evaporation method; then, depositing a silicon carbide-silicon dioxide nano polymer on the perovskite film by using a spin coating method or a chemical vapor deposition method; and finally, depositing a metal electrode on the silicon carbide-silicon dioxide nano polymer by adopting a vacuum evaporation method or a screen printing method to obtain the solar cell.