Back to Search Start Over

Raman spectra evidence for the covalent-like quasi-bonding between exfoliated MoS2 and Au films

Raman spectra evidence for the covalent-like quasi-bonding between exfoliated MoS2 and Au films

Authors :
Xinyu Huang
Liwei Liu
Qiong Wu
Wei Ji
Xingjiang Zhou
Lei Liu
Yang Qin
Yeliang Wang
Zhenhua Ni
Qiang Fu
Jun-Peng Lv
Yuan Huang
Rong Yang
Lei Zhang
Source :
Science China Information Sciences. 64
Publication Year :
2021
Publisher :
Springer Science and Business Media LLC, 2021.

Abstract

Gold-enhanced mechanical exfoliation method attracts broad interests in recent years, which has been widely used for preparing large-area and high-quality 2D single crystals. Even many calculations predict that there is strong interaction between Au film and the exfoliated 2D crystals, direct experimental evidence is still lacking. Here, we perform Raman spectroscopy measurements for few layer MoS2 with and without Au film underneath. The main peaks of MoS2 on Au film show no obvious change at higher frequency, however, the breathing and shear modes at low-frequency are suppressed, especially for breathing modes. In contrast, both breathing modes and shear modes can be detected on suspended MoS2 and the samples are transferred from Au film to SiO2/Si. These comparison results provide direct evidence for the existence of covalent-like quasi-bonding at the interface of Au film and the exfoliated MoS2 crystal. This MoS2/Au interface interaction presents a special pinning-effect for low-frequency rigid vibration. Similar pinning-effect is also discovered in WS2/Au system. Our work reports the suppression of low-frequency Raman modes of MoS2, WS2 on Au film, which will deliver new inspiration for studying other interactions between layered materials and solid surfaces.

Details

ISSN :
18691919 and 1674733X
Volume :
64
Database :
OpenAIRE
Journal :
Science China Information Sciences
Accession number :
edsair.doi...........ff817af032252df43c5f8eedb4eb71fe
Full Text :
https://doi.org/10.1007/s11432-020-3173-9