Band gap engineering of atomically thin two-dimensional semiconductors*
Project supported by the National Natural Science Foundation of China (Grant Nos. 11374092, 61474040, 61574054, and 61505051), the Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province, China, and the Science and Technology Department of Hunan Province, China (Grant No. 2014FJ2001).
Ge Cui-Huan, Li Hong-Lai, Zhu Xiao-Li ‡, Pan An-Lian †
(color online) (a) Schematic illustration of the transformation from WO (monoclinic crystal) to WSSe (hexagonal crystal) through simultaneous sulfurization and selenization processes.[62] (b) Optical microscopy image of typical WSSe nanosheets (x = 0.454; scale bar = 20 μm.[64] (c) HRSTEM image of the as-grown monolayer WSSe (x = 0.43).[42] (d) HAADF image of a small WSSe domain (x = 0.573; scale bar = 500 nm) and EDS mapping of the same triangular domain for S–K line, Se–K line, and W–L line, respectively.[64] (e) Evolution of Raman spectra in the WSSe monolayer nanosheets as a function of chemical composition: full-range Raman spectra, E–LA + A–LA mode, A of Se–W mode, and E of S–W mode, A of S–W–Se mode, and A of S–W mode.[64]
