Stable α-CsPbI3 perovskite nanowire arrays with preferential crystallographic orientation for highly sensitive photodetectors

Gaosong Chen, Jiangang Feng, Hanfei Gao, Yingjie Zhao, Yueyang Pi, Xiangyu Jiang, Yuchen Wu, Lei Jiang

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42 Citations (Scopus)

Abstract

All-inorganic metal-halide perovskites CsPbX 3 (X = Cl, Br, I) exhibit higher stability than their organic–inorganic hybrid counterparts, but the thermodynamically instable perovskite α phase at room temperature of CsPbI 3 restricts the practical optoelectronic applications. Although the stabilization of α-CsPbI 3 polycrystalline thin films is extensively studied, the creation of highly crystalline micro/nanostructures of α-CsPbI 3 with large grain size and suppressed grain boundary remains challenging, which impedes the implementations of α-CsPbI 3 for lateral devices, such as photoconductor-type photodetectors. In this work, stable α-CsPbI 3 perovskite nanowire arrays are demonstrated with large grain size, high crystallinity, regulated alignment, and position by controlling the dewetting dynamics of precursor solution on an asymmetric-wettability topographical template. The correlation between the higher photoluminescence (PL) intensity and longer PL lifetime indicates the nanowires exhibit stable α phase and suppressed trap density. The preferential (100) orientation is characterized by discrete diffraction spots in grazing incidence wide-angle scattering patterns, suggesting the long-range crystallographic order of these nanowires. Based on these high-quality nanowire arrays, highly sensitive photodetectors are realized with a responsivity of 1294 A W −1 and long-term stability with 90% performance retention after 30-day ambient storage.

Original languageEnglish
Article number1808741
Number of pages7
JournalAdvanced Functional Materials
Volume29
Issue number13
DOIs
Publication statusPublished - 28 Mar 2019
Externally publishedYes

Keywords

  • metal-halide perovskite
  • nanowire array
  • photodetector
  • preferential crystallographic orientation
  • stable α-CsPbI

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