Author(s): Zou, B (Zou, Bo); Zhou, Y (Zhou, Yu); Zhou, Y (Zhou, Yan); Wu, YY (Wu, Yanyan); He, Y (He, Yang); Wang, XN (Wang, Xiaonan); Yang, JF (Yang, Jinfeng); Zhang, LH (Zhang, Lianghui); Chen, YX (Chen, Yuxiang); Zhou, S (Zhou, Shi); Guo, HX (Guo, Huaixin); Sun, HR (Sun, Huarui)

Source: NANO RESEARCH DOI: 10.1007/s12274-022-4418-z Early Access Date: JUN 2022

Abstract: The emerging Au-assisted exfoliation technique enables the production of a wealth of large-area and high-quality ultrathin two dimensional (2D) crystals. Fast, damage-free, and reliable determination of the layer number of such 2D films can greatly promote layer-dependent physical studies and device applications. Here, an optical method has been developed for simple, high throughput, and accurate determination of the layer number for Au-assisted exfoliated MoS2 and WS2 films in a broad thickness range. The method is based on quantitative analysis of layer-dependent white light reflection spectra (WLRS), revealing that the intensity of exciton-induced reflection peaks can be used as a clear indicator for identifying the layer number. The simple yet robust method will facilitate fundamental studies on layer-dependent optical, electrical, and thermal properties and device applications of 2D materials. The technique can also be readily combined with photoluminescence (PL) and Raman spectroscopies to study other layer-dependent physical properties of 2D materials.

Accession Number: WOS:000805729300006

ISSN: 1998-0124

eISSN: 1998-0000

Full Text: https://link.springer.com/article/10.1007/s12274-022-4418-z