Research On Planar Heterojunction Organic-inorganic Hybrid Perovskite Solar Cells

In recent years, organic-inorganic hybrid perovskite solar cells have attracted much attention of scholars and research institutes with the simple preparation process, abundant materials, lower costs, broad absorption to light and friendly to environment, and its performance is close to conventional polycrystalline silicon solar cells with the increased efficiency and stability and shows the bright prospects. Optimization to preparation process and device architectures is an important part of perovskite solar cells, such as one-step and two-step solution-processing method, planar structure and mesoporous structure, conventional structure and inverted structure.In this thesis, the history and main categories of solar cells were summarized firstly.then on the base of which the content of this study was puts forward:devices which have a simple planar structure were preparated by two-step solution-processing method and the impact of different annealing time of perovskite layer to device performance and the impact of different reaction time between Pbl2 and CH3NH3I to device performance were researched. Finally, this thesis makes a summary and points out the problems and something to do in future. The results are as follows:1.The impact of different annealing time of perovskite layer to device performance:device efficiencies increase as the annealing time increase initially, and decreases afterwards and then increase. It has the same trend to Voc and Jsc Perovskite solar cells got the best performance when annealing time is lOmin. The main reason for the best performance is the better Rs and Rsh, which lead to better VOC,JSC and FF.2.The impact of different reaction time between Pbl2 and CH3NH3I to device performance:device efficiencies increase as the annealing time increase initially, and decreases afterwards. Perovskite solar cells got the best performance when reaction time was set to 60s. However, Voc, Jsc and PCE of solar cells in this thesis are very low and the device performance is not ideal and further researth is need to do. At this time, the grain size of perovskite is biggest and the grains are arrange close together. It is good for charge separation and transportaion of carrier and reduce the recombination of carrier. Through this way, lower Rs and higher Rsh was got, which lead to higher Voc, Jsc, FF and better performance of cells.