Selective Surface Engineering of Perovskite Microwire Arrays

摘要

The surface of low-dimensional perovskites play a crucial role in determiningtheir intrinsic property. Understanding their characteristics and the influenceof certain surfaces is valuable in designing functional surface-engineeredstructures. Meanwhile, surface passivation can also be applied to stabilize andoptimize the state-of-the-art perovskite-based optoelectronics. Herein, cesiumlead bromide (CsPbBr_3) microwire parallel arrays are designed and fabricatedwith specific (100)-terminated crystal planes, which exhibit excellent photodetectionperformance with long-term environment stability >3000 h. Notably,it is uncovered experimentally and theoretically that environmental oxygencan not only passivate the Br-vacancy-related trap states on the (100) surface,but also create charge carrier nanochannels to enhance the (opto)electronicproperties. The coupling effects between oxygen species and the specificterminated crystal planes of perovskites highlight the importance of surfaceengineering for designing and optimizing perovskite-based devices.