肖特基钙钛矿太阳电池结构设计与优化

有机-无机杂化钙钛矿材料有高吸收系数、低廉的制作成本以及较为简单的制备工艺,在近年来表现出良好的发展前景.本文采用wx-AMPS模拟软件对平面结构钙钛矿太阳电池和肖特基钙钛矿太阳电池进行建模仿真对比,从理论上分析无载流子传输层的肖特基钙钛矿太阳电池的优势.结果显示,器件两侧电极功函数和吸收层的能带分布是提高太阳电池效率的关键.在对电极使用Au(功函数为5.1 eV)的前提下,透明导电电极功函数为3.8 eV,可以得到肖特基钙钛矿太阳电池转换效率为17.93%.对器件模型吸收层进行优化,通过寻找合适的掺杂浓度,抑制缺陷密度,确定合适的厚度,可以获得理想的转换效率(20.01%),是平面异质结结构(理论转换效率31%)的63.84%.肖特基钙钛矿太阳电池在简单的器件结构下可以获得优异的光电性能,具有较好的应用潜力.

Simulation and architectural design for Schottky structure perovskite solar cells

The wx-AMPS simulation software is used to model and simulate the Schottky perovskite thin film solar cells. The front and back electrodes with different work functions are applied to the Schottky perovskite solar cells to study the effect of band structure on the performance of solar cells. The results show that in a range from 3.8 to 4.4 eV, as the work function of the front electrode decreases, the conversion efficiency of the Schottky solar cells gradually increases. When the work function of the front electrode is low, the electric field strength is large, which facilitates the transport of carriers in the light-absorbing layer of the perovskite and reduces the carrier recombination rate of the perovskite layer. In addition, the recombination ratio of the light absorbing layer is reduced due to the increase of the electric field strength, and the parallel resistance is increased to a certain extent thereby increasing the FF and improving the output efficiency of the battery. At the same time, when the current electrode work function is maintained at 3.8 eV, in a range from 4.3 to 5.5 eV,the higher the work function of the back electrode, the greater the conversion efficiency of the Schottky solar cell is. This conduces to the band alignment in contact between perovskite and back electrode. Under the premise that the common electrode Au is used as a back electrode, the work function of the front electrode is3.8 eV and the conversion efficiency of the Schottky perovskite solar cell is 17.93%. In addition, by using the optimized front and rear contact electrodes, the quality of the perovskite layer material, thus the performance of the solar cell can be further improved. Doping till a certain concentration and removing the defects of the perovskite layer, the conversion efficiency of the solar cell with a thickness of 500 nm can be increased from17.93% to 20.1%. The simulation results show that the Schottky perovskite thin film solar cells can obtain excellent performance with simple device structure and have great potential applications.