Room‐Temperature Crystallization of Ultralong (≈3.5 mm) CsCu2I3 Microbelt to Suppress Carrier Recombination for High‐Performance UV Heterojunction Photodetector. Issue 4 (13th December 2021)

• Record Type: Journal Article
• Authors: Li, Ziqing; Zuo, Chaolei; Liu, Xinya; Ma, Zhuangzhuang; Shi, Zhifeng; Fang, Xiaosheng
• Is Part Of: Advanced optical materials. Volume 10:Issue 4(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-13
• Subjects: heterojunctions -- lead‐free halide perovskite analogue -- photophysical processes -- ultralong microbelts -- UV photodetectors; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.202102315
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Lead‐free ternary copper iodide perovskite analogues demonstrate great potential in photodetector, due to their nontoxity and excellent photophysical properties. However, the fast carrier recombination limits the photoelectric conversion efficiency. Herein, a room‐temperature growth strategy with the selected raw ratio is adopted to enhance carrier dynamics. The optimized‐grown CsCu2 I3 single crystal exhibits longer carrier lifetime of 157 ns, and its switch ratio and response time are enhanced by 20 000% and 600% compared with those of stoichiometric‐grown single crystal, respectively. Furthermore, space‐confined method is introduced to prepare ultralong single‐crystalline CsCu2 I3 microbelt, with the aspect ratio up to 600. The sensitivity and self‐powered performance of the UV photodetector are improved through constructing heterojunction with p‐CuI and asymmetric electrodes. The enhanced performance is ascribed to superior type‐II band alignment between CsCu2 I3 and CuI, which effectively promotes the separation of photogenerated carriers. This work not only provides an efficient way to boost the photoresponse in low‐dimensional metal halide perovskite analogue, but also displays 1D anisotropic growth for potential application in large‐area vapor‐assisted patterned devices. Abstract : Room‐temperature crystallization strategy is adopted to grow high‐quality CsCu2 I3 single crystal, which demonstrates enhanced photoelectric performance, due to suppressed carrier recombination. Furthermore, UV heterojunction photodetector based on ultralong single‐crystalline CsCu2 I3 microbelt, is successfully constructed and exhibits comparable photoelectric performance to those of state‐of‐the‐art lead‐free halide perovskite analogue photodetectors.