基于逐层气相沉积制备的钙钛矿薄膜调控和器件性能优化

Perovskite Film Regulation and Device Performance Optimization Based on Layer-by-Layer Vapor Deposition

摘要:

真空气相沉积法具有致密性好、均匀性好、膜厚可控等优点，被认为是一种制备大面积、高质量钙钛矿薄膜的关键技术，在工业化生产上有着巨大的应用潜力。但相较于溶液法，气相沉积存在薄膜晶粒尺寸小，结晶度低等缺点，导致器件光电转换效率较低。采用逐层交替气相沉积法制备钙钛矿薄膜，对碘化铅(PbI₂)含量进行调控，使用氯化甲胺和碘化甲铵混合溶液进行表面后处理，钝化了薄膜缺陷，提升了薄膜质量。PbI₂含量的优化调控了钙钛矿薄膜的化学计量比，器件光电性能得到提高。表面后处理引入的氯离子，使钙钛矿晶粒尺寸增大，结晶度提高。器件的短路电流密度明显提升，最终获得17.76%的光电转换效率以及82.1%的填充因子。

Abstract:

The vacuum vapour deposition method has the advantages of good denseness， uniformity and controllable film thickness， and is considered a key technology for preparing large-area， high-quality perovskite films， which has great potential for industrial production. However， compared with the solution method， vapour phase deposition has the disadvantages of small film grain size and low crystallinity， resulting in lower device photoelectric conversion efficiency. In this paper， we use layer-by-layer alternating vapour deposition method to prepare perovskite thin films， and the PbI₂ content is regulated and the surface post-treatment of MACl and MAI mixed solution can passivate the defects and improve the quality of the films. The chloride ions introduced by the surface post-treatment increase the size of the perovskite grains and improve the crystallinity. The short-circuit current density of the device was significantly increased， resulting in a final photovoltaic conversion efficiency of 17.76% and a fill factor of 82.1%.