Raman Spectroscopy of Two-Dimensional Borophene Sheets
Authors: Sheng, SX; Wu, JB; Cong, X; Zhong, Q; Li, WB; Hu, WQ; Gou, J; Cheng, P; Tan, PH; Chen, L; Wu, KH
Volume: 13 Issue: 4 Pages: 4133-4139 Published: APR 2019 Language: English Document type: Article
The successful fabrication of a two-dimensional boron sheet, which features a triangular lattice with periodic hole arrays, has stimulated great interest in its specific structure as well as properties such as possible superconductivity. Here, we report a study on the vibrational spectra and electron-phonon coupling (EPC) in monolayer boron sheets by in situ Raman and tip enhanced Raman spectroscopy (TERS) at low temperature and ultrahigh vacuum. The gap-mode TERS gives a 3 x 10(9) selective enhancement on vertical vibrational Raman modes. A spatial resolution of 1 nm is achieved in this system. Combined with first-principle calculations, the vibrational properties as well as EPC in borophene are determined. The results are helpful for further study on the mechanical, electronic, and possible superconducting properties of two-dimensional boron.