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CsPbX 3 ‐ITO (X = Cl, Br, I) Nano‐Heterojunctions: Voltage Tuned Positive to Negative Photoresponse
Author(s) -
He Qiqian,
Chen Gaoyu,
Wang Yongkai,
Liu Xiaoyu,
Xu Danting,
Xu Xiangxing,
Liu Ying,
Bao Jianchun,
Wang Xun
Publication year - 2021
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.202101403
Subject(s) - materials science , heterojunction , optoelectronics , indium tin oxide , quantum dot , exciton , perovskite (structure) , photoconductivity , photodetector , nanocrystal , nano , nanomaterials , indium , nanotechnology , thin film , chemistry , physics , composite material , crystallography , quantum mechanics
All‐Inorganic perovskite CsPbX 3 (X = Cl, Br, I) quantum dots (QDs) have attracted tremendous attention in the past few years for their appealing performance in optoelectronic applications. Major properties of CsPbX 3 QDs include the positive photoconductivity (PPC) and the defect tolerance of the in‐band trap states. Here it is reported that when hybridizing CsPbX 3 QDs with indium tin oxide (ITO) nanocrystals to form CsPbX 3 ‐ITO nano‐heterojunctions (NHJs), a voltage tuned photoresponse—from PPC to negative photoconductivity (NPC) transform—is achieved in lateral drain‐source structured ITO/CsPbX 3 ‐ITO‐NHJs/ITO devices. A model combining exciton, charge separation, transport, and most critical the voltage driven electron filling of the in‐band trap states with drain–source voltage ( V DS ) above a threshold, is proposed to understand this unusual PPC‐NPC transform mechanism, which is different from that of any known nanomaterial system. This finding exhibits potentials for developing devices such as photodetectors, optoelectronic switches, and memories.