Imaging Spatial Distribution of Photogenerated Carriers in Monolayer MoS 2 with Kelvin Probe Force Microscopy.

Autor: Yim W; Department of Physics and Department of Energy Systems Research, Ajou University, Suwon 16499, Korea., Nguyen VT; Institute of Materials Science, Vietnam Academy of Science and Technology, Hanoi 100000, Vietnam., Phung QT; Department of Physics and Department of Energy Systems Research, Ajou University, Suwon 16499, Korea., Kim HS; Department of Physics and Department of Energy Systems Research, Ajou University, Suwon 16499, Korea., Ahn YH; Department of Physics and Department of Energy Systems Research, Ajou University, Suwon 16499, Korea., Lee S; Department of Physics and Department of Energy Systems Research, Ajou University, Suwon 16499, Korea., Park JY; Department of Physics and Department of Energy Systems Research, Ajou University, Suwon 16499, Korea.
Jazyk: angličtina
Zdroj: ACS applied materials & interfaces [ACS Appl Mater Interfaces] 2022 Jun 08; Vol. 14 (22), pp. 26295-26302. Date of Electronic Publication: 2022 May 25.
DOI: 10.1021/acsami.2c06315
Abstrakt: The spatial distribution of photogenerated carriers in atomically thin MoS 2 flakes is investigated by measuring surface potential changes under light illumination using Kelvin probe force microscopy (KPFM). It is demonstrated that the vertical redistribution of photogenerated carriers, which is responsible for photocurrent generation in MoS 2 photodetectors, can be imaged as surface potential changes with KPFM. The polarity of surface potential changes points to the trapping of photogenerated holes at the interface between MoS 2 and the substrate as a major mechanism for the photoresponse in monolayer MoS 2 . The temporal response of the surface potential changes is compatible with the time constant of MoS 2 photodetectors. The spatial inhomogeneity in the surface potential changes at the low light intensity that is related to the defect distribution in MoS 2 is also investigated.
Databáze: MEDLINE
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