Tang Guanqi, You Peng, Tai Qidong, Yang Anneng, Cao Jiupeng, Zheng Fangyuan, Zhou Zhiwen, Zhao Jiong, Chan Paddy Kwok Leung, Yan Feng
Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Department of Mechanical Engineering, The University of Hong Kong, Pok Fu Lam Road, Hong Kong.
Adv Mater. 2019 Jun;31(24):e1807689. doi: 10.1002/adma.201807689. Epub 2019 Apr 29.
The quality of perovskite films is critical to the performance of perovskite solar cells. However, it is challenging to control the crystallinity and orientation of solution-processed perovskite films. Here, solution-phase van der Waals epitaxy growth of MAPbI perovskite films on MoS flakes is reported. Under transmission electron microscopy, in-plane coupling between the perovskite and the MoS crystal lattices is observed, leading to perovskite films with larger grain size, lower trap density, and preferential growth orientation along (110) normal to the MoS surface. In perovskite solar cells, when perovskite active layers are grown on MoS flakes coated on hole-transport layers, the power conversion efficiency is substantially enhanced for 15%, relatively, due to the increased crystallinity of the perovskite layer and the improved hole extraction and transfer rate at the interface. This work paves a way for preparing high-performance perovskite solar cells and other optoelectronic devices by introducing 2D materials as interfacial layers.
钙钛矿薄膜的质量对钙钛矿太阳能电池的性能至关重要。然而，控制溶液法制备的钙钛矿薄膜的结晶度和取向具有挑战性。在此，报道了在MoS薄片上通过溶液相范德华外延生长MAPbI钙钛矿薄膜。在透射电子显微镜下，观察到钙钛矿与MoS晶格之间的面内耦合，从而得到具有更大晶粒尺寸、更低陷阱密度且沿垂直于MoS表面的(110)方向择优生长取向的钙钛矿薄膜。在钙钛矿太阳能电池中，当钙钛矿活性层生长在涂覆于空穴传输层上的MoS薄片上时，由于钙钛矿层结晶度的提高以及界面处空穴提取和转移速率的改善，功率转换效率相对大幅提高了15%。这项工作通过引入二维材料作为界面层，为制备高性能钙钛矿太阳能电池和其他光电器件铺平了道路。
