Universal Mechanism of Band-Gap Engineering in Transition-Metal Dichalcogenides
SCIE
SCOPUS
- Title
- Universal Mechanism of Band-Gap Engineering in Transition-Metal Dichalcogenides
- Authors
- Kang, M.; Kim, B.; Ryu, S.H.; Jung, S.W.; Kim, J.; Moreschini, L.; Jozwiak, C.; Rotenberg, E.; Bostwick, A.; Kim, K.S.
- Date Issued
- 2017-03
- Publisher
- AMER CHEMICAL SOC
- Abstract
- van der Waals two-dimensional (2D) semiconductors have emerged as a class of materials with promising device characteristics owing to the intrinsic band gap. For realistic applications, the ideal is to modify the band gap in a controlled manner by a mechanism that can be generally applied to this class of materials. Here, we report the observation of a universally tunable band gap in the family of bulk 2H transition metal dichalcogenides (TMDs) by in situ surface doping of Rb atoms. A series of angle-resolved photoemission spectra unexceptionally shows that the band gap of TMDs at the zone corners is modulated in the range of 0.8-2.0 eV, which covers a wide spectral range from visible to near-infrared, with a tendency from indirect to direct band gap. A key clue to understanding the mechanism of this band-gap engineering is provided by the spectroscopic signature of symmetry breaking and resultant spin-splitting, which can be explained by the formation of 2D electric dipole layers within the surface bilayer of TMDs. Our results establish the surface Stark effect as a universal mechanism of band-gap engineering on the basis of the strong 2D nature of van der Waals semiconductors. ? 2017 American Chemical Society.
- Keywords
- III-V semiconductors; Infrared devices; Semiconductor doping; Stark effect; Transition metals; Van der Waals forces; Angle-resolved photoemission; Band gap engineering; Device characteristics; Giant stark effects; Realistic applications; Spectroscopic signatures; Transition metal dichalcogenides; Two-dimensional semiconductors; Energy gap
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/92123
- DOI
- 10.1021/acs.nanolett.6b04775
- ISSN
- 1530-6984
- Article Type
- Article
- Citation
- NANO LETTERS, vol. 17, no. 3, page. 1610 - 1615, 2017-03
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