钙钛矿/铁电异质结太阳能电池的光伏效应及电荷传输机制研究

项目名称： 钙钛矿/铁电异质结太阳能电池的光伏效应及电荷传输机制研究

项目编号： No.11474199

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 郭益平

作者单位： 上海交通大学

项目金额： 84万元

中文摘要： 有机-无机杂化钙钛矿太阳能电池由于其低的制作成本及优越的光伏效应而备受瞩目，但目前关于钙钛矿电池中各个界面对电荷分离及传输的作用机制尚不清楚。铁酸铋光伏材料不仅具有良好的电子传导特性，而且可以通过铁电极化调制优化异质结界面处的能级排列来促进电荷的分离。因此将铁酸铋引入到钙钛矿太阳能电池中不仅可望提高其光电转换效率，也是我们研究钙钛矿电池中电荷分离与传输机制的理想对象。本次申请通过超声喷雾热解法制备CH3NH3PbI3薄膜，研究BFO/CH3NH3PbI3平面异质结和它们的共混膜体异质结的微/纳结构特征对光伏特性的影响，研究脉冲极化电压对异质结电池的光伏效应及载流子的传导特性、荧光淬灭特性和复合特性的影响，分别揭示肖特基势垒和异质结界面处势垒对电荷分离及传输的作用机制，揭示铁电退极化场与载流子复合之间的内在关系，为制作具有更加优越光伏特性的有机-无机杂化钙钛矿太阳能电池提供实验和理论依据。

中文关键词： 有机-无机杂化钙钛矿；光伏特性；铁电极化；能带结构；电荷传输

英文摘要： Organic-inorganic hybrid perovskite materials are a promsing, low cost,easily synthesized set of materials.They act as light absorber and both electron and hole transport. High efficiency exceeding 15% for the perovskite based solar cells has been reached and thus they have attracted much attention recently. However, the photophysical properties made them so promsing are still unclear, e.g. what is the precise role of each interface in the device? what is the dissociation mechanism of carrier in the perovskite? BiFeO3 (BFO) with perovskite structure has high ferroelectric polarization and good electron transport properties. Ferroelectrics have been used to improve the photovoltaic or photoelectrochemical properties in oxide semiconductor and organic photovoltaic solar cells because the ferroelectric polarization is able to modulate the energy band or accelerate the dissociation of carrier(exciton).Therefore,the introduction of BFO to perovskite should be beneficial to enhance the photovoltaic effect of perovskite based solar cells and be a good candidate for investigating the role of different interfaces and the dissociation mechanism of carrier(exciton)in the perovskite. In this project,CH3NH3PbI3 thin films will be prepared by ultrasonic spray pyrolysis method. Planar heterojunctions perovskite solar cells by using BFO nanoparticle layer as electronic transport layer and bulk heterojuntion perovskite solar cells based on the co-deposition of a combined BFO-perovskite layer will be formed. The relationship between micro/nano structure and photovoltaic effect will be analyzed. The ferroelectric polarization on photovoltaic effect, charge transport characteristics, and fluorescence quenching properties will be investigated. Our work will help us to clarify the precise role of each interface in the device and the dissociation mechanism of carrier(exciton) in the perovskite. This project therefore will provide insight into ways finding a new photovoltaic technology with good photovoltaic effect.

英文关键词： organic-inorganic hybrid perovskite;photovoltaic;ferroelectric polarization;energy band strcture;charge transport