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Engineered Surface Halide Defects by Two-Dimensional Perovskite Passivation for Deformable Intelligent Photodetectors.

Authors :
Kim T
Jeong S
Kim KH
Shim H
Kim D
Kim HJ
Source :
ACS applied materials & interfaces [ACS Appl Mater Interfaces] 2022 Jun 08; Vol. 14 (22), pp. 26004-26013. Date of Electronic Publication: 2022 May 23.
Publication Year :
2022

Abstract

As attractive photoactive materials, metal halide perovskites demonstrate outstanding performance in a wide range of optoelectronic applications. Among the various compositions studied, mixed-halide perovskites have a finely tunable band gap that renders them desirable for targeted applications. Despite their advantages, photoinduced halide segregation often deters the photoelectric stability of the materials. Herein, we adopt a strategy of post-treating the perovskite surface with an organic spacer to generate a two-dimensional (2D) perovskite passivating layer. Trap-assisted recombination pathways can be selectively modulated by passivating the surface halide defects that cause photoinduced halide segregation. Fluorescence lifetime imaging of flat and bent surfaces of perovskites reveals that the perovskite lattice tolerates mechanical strain via the neutralizing passivation of ionic halide defects. Upon bending, the photocurrent response of the flexible photodetector is maintained over 83% for 2D passivated perovskite and drops to 23% for pristine perovskite. A flexible photodetector array built with 2D passivated perovskite, in combination with a deep learning algorithm, demonstrates excellent accuracy in determining letters of the alphabet for both flat (>96%) and bent (>93%) states. The connection of chemically modified charge carrier dynamics and mechanical properties revealed in this study offers valuable guidance for developing next-generation optoelectronic applications.

Details

Language :
English
ISSN :
1944-8252
Volume :
14
Issue :
22
Database :
MEDLINE
Journal :
ACS applied materials & interfaces
Publication Type :
Academic Journal
Accession number :
35604641
Full Text :
https://doi.org/10.1021/acsami.2c03089