Optical studies of 1T-VSe2 single crystals and nanosheets
Yen-Ting Wang(王嬿婷)1, Song-Hsun Huang(黃松勳)1,2, Sankar Raman2, Fang-Cheng Chou(周方正)2, Hsiang-Lin Liu(劉祥麟)1
1Department of Physics, National Taiwan Normal University, Taipei, Taiwan
2Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan
* presenting author:YENTING WANG, email:b.c.1991@hotmail.com
Layered transition metal dichalcogenides have attracted much attention in recent years because of their unique physical properties and potential practical applications. In this work we investigate the electronic structures and lattice dynamics of 1T-VSe2 single crystals and nanosheets. The optical absorption spectrum of 1T-VSe2 single crystals shows two bands near 1.16, and 5 eV. The first peak was attributed to a transition between occupied and unoccupied states of V 3d orbitals. The second peak was attributed to charge transfer transitions between Se 2p and V 3d states. The Raman scattering spectrum of 1T-VSe2 single crystals shows two major phonon modes at approximately 138 and 207 cm-1, displaying symmetries of Eg and A1g. The evolution of electronic and vibrational excitations in 1T-VSe2 nanosheets will be discussed.

Keywords: Transition metal dichalcogenides, Vanadium selenide, Electronic structures, Lattice dynamics