Transition-metal dichalcogenides are currently under rigorous investigation because of their distinct layer-dependent physical properties originating from the corresponding evolution of the band structure. Here, we report the highly resolved probing of layer-dependent band structure evolution for WSe2 using photoexcited charge collection spectroscopy (PECCS). Monolayer, few-layer, and multilayer WSe2 can be probed in top-gate field-effect transistor platforms, and their interband transitions are efficiently observed. Our theoretical calculations show a great coincidence with the PECCS results, proving that the indirect ⌈-K and ⌈-λ transitions as well as the direct K-K transition are clearly resolved in multilayer WSe2 by PECCS.
Bibliographical noteFunding Information:
This research was supported by the SRC program: vdWMRC Center through the National Research Foundation (NRF) of Korea funded by the Ministry of Education (Grant 2017R1A5A1014862). K.L. and H.B. acknowledge the Basic Science Research Program through the NRF (Grants 2016R1D1A3B03933785 and 2017R1D1A1B03028257). S.O. and H.J.C. acknowledge support from the NRF (Grant 2011-0018306). Computational resources were provided by the KISTI Supercomputing Center (Project KSC-2017-C3-0079).
© 2018 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Materials Science(all)