• Optical Instruments
  • Vol. 44, Issue 1, 63 (2022)
Xinlin YE and Guanjun YOU*
Author Affiliations
  • School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
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    DOI: 10.3969/j.issn.1005-5630.2022.01.010 Cite this Article
    Xinlin YE, Guanjun YOU. Terahertz near-field microscopic imaging study of monolayer MoS2 and WS2[J]. Optical Instruments, 2022, 44(1): 63 Copy Citation Text show less

    Abstract

    In this paper, the terahertz near-field response of monolayer MoS2 and WS2 grains prepared by chemical vapor deposition was investigated by terahertz scattering scanning near-field optical microscopy (THz s-SNOM). No resolvable terahertz near-field response was detected in the absence of visible excitation, indicating that the grains have a low doped carrier concentration. With visible light excitation, we were able to measure a terahertz near-field micrograph that exactly matches the grain profile due to the terahertz near-field response of the photogenerated carriers. Under the same photoexcitation conditions, the terahertz near-field response of MoS2 is stronger than that of WS2, it reflects the difference of carrier concentration or mobility between them. The results show that THz s-SNOM combines ultra-high spatial resolution and sensitive detection of photogenerated carriers. It is uniquely suited for micromechanics studies of the optoelectronic properties of two-dimensional semiconductor materials and devices.
    Xinlin YE, Guanjun YOU. Terahertz near-field microscopic imaging study of monolayer MoS2 and WS2[J]. Optical Instruments, 2022, 44(1): 63
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