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Title: Unveiling defect-mediated carrier dynamics in monolayer semiconductors by spatiotemporal microwave imaging
Significance Defects in two-dimensional (2D) transition-metal dichalcogenides play a crucial role in controlling the spatiotemporal dynamics of photogenerated charge carriers, which remain poorly understood to date. In this paper, the defect-mediated carrier diffusion and recombination in WS2monolayers are quantitatively investigated by laser-illuminated microwave impedance microscopy. Surprisingly, the photoresponse is in general stronger in the more disordered regions and samples. Such counterintuitive observations are reconciled by spatiotemporally resolved experiments, which indicate that the electron lifetime is prolonged due to the slow release of holes from the trap states. The results reveal the intrinsic time and length scales of photocarriers in van der Waals materials, providing the guidance for implementing nanooptoelectronic devices based on 2D semiconductors.  more » « less
Award ID(s):
1720595
PAR ID:
10474904
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
The Proceedings of the National Academy of Sciences
Date Published:
Journal Name:
Proceedings of the National Academy of Sciences
Volume:
117
Issue:
25
ISSN:
0027-8424
Page Range / eLocation ID:
13908 to 13913
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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