Fabrication Of Highly Efficient And Stable Perovskite Solar Cells

Energy is the foundation of the development of human society.The continued use of traditional fossil fuels,such as coal,oil and natural gas,will cause a large amount of problems,such as energy crisis and environmental pollution.In this case,the development and application of clean energy is particularly important.Solar energy is one of the most important renewable energy for human.The solar energy can be directly converted into the electrical energy by the solar cells,which is more efficient comparing with any other utilization of solar energy.The perovskite solar cells have attracted the attention of a large number of scientific researchers,because of the rich raw materials,simple preparation technology and the excellent ability to capture light that make it a great potential of thin-film solar cells.However,so far,the perovskite solar cells still have a lot of problems to resolve,such as poor stability,environmental pollution,and the mechanism,etc.These problems greatly affect the industrialized production of perovskite solar cells.What’s more,the power conversion efficiency of perovskite solar cells achieved so far is far from its theoretical value;namely,there have a lot of room to improve.In order to further improve the stability and power conversion efficiency of the device,we carried out our research.(1)Improvement of the stability for the perovskite solar cells.First,the structure of the perovskite materials is ABX3.When the radius of three kinds of ions or groups satisfy certain conditions,the perovskite materials with excellent photovoltaic performance can be formed.Secondly,CH3NH3PbI3 is very sensitive to water and oxygen.Long time exposure in air will accelerate its decomposition.In addition,the continued lighting of perovskite solar cells under solar simulator will enhance the built-in electric field driven by CH3NH3+ and I-,which will also weaken the stability of the perovskite solar cells.Based on CH3NH3PbI3,we tried to fix ions during the formation of perovskite layer,and thus weaken or eliminate the effect of the ion migration for the devices.Finally,the stability of device was improved.(2)Improvement of the power conversion efficiency for the perovskite solar cells.Based the gap between the actual values and theoretical value of the power conversion efficiency,the transitional metal ions Zn2+ was added to perovskite precursor solutions to improve the quality of perovskite thin film,the ability of capture light and the lifetime of minority carriers,and finally improve the power conversion efficiency.