In Situ Surface Modification Enables High Stability and Optoelectrical Performance for a Self‐powered Photodetector

作者：Duanwangde Liu, Zhiliang Chen, Zuoxin Huang, Qi Wu, Yangguang Song, Jianfeng Yao, Hu Zhang, Shengyang Wei, Liangpan Yang, Jixue Chen, Wenlong Shao, Lingling Chu, Yanhui Li, Pengbin Gui, Xingang Ren, Wei Zeng, Guojia Fang · 发表于：Advanced Optical Materials · 年份：2023 · DOI：10.1002/adom.202300940 · 被引用次数：11 · 研究领域：Perovskite Materials and Applications、ZnO doping and properties、Quantum Dots Synthesis And Properties

Abstract Perovskite single crystals (SCs) have gained significant interest in various applications owing to their superior optoelectrical and physical characteristics as compared to polycrystalline films. However, a considerable portion of incident light is typically reflected at the surface of perovskite SCs, leading to insufficient light absorption within the crystal bulk, ultimately resulting in reduced performance of SC‐based photodetectors. In the present work, an inverted pyramid‐shaped structure is in situ introduced on the surface of an MAPbBr 3 SC during the crystal growth process, which can reduce light reflection in the surface region and enhance light absorption of the SC. Additionally, the hydrophobic small molecule copper (II) phthalocyanine (CuPc) is thermally evaporated onto the SC, forming a CuPc/MAPbBr 3 heterojunction for the first time. The CuPc/pyramid‐shaped MAPbBr 3 heterojunction‐based photodetector exhibits self‐powered characteristics and superior optoelectrical performance, achieving a photocurrent of greater than 10 −5 A (10 −7 A), a responsiveness of 257 mA W −1 (8.84 mA W −1 ), and a detection rate of 2.98 × 10 12 Jones (1.02 × 10 11 Jones) at −2 V (0 V) bias. Simultaneously, the device demonstrates excellent long‐term stability under high humidity conditions, retaining 90.5% of its initial photocurrent even after 60 days in a 60–80% humidity environment.