Optical signature of symmetry variations and spin-valley coupling in atomically thin tungsten dichalcogenides

• Published in: Scientific reports Vol. 3; no. 1; p. 1608
• Main Authors: Zeng, Hualing, Liu, Gui-Bin, Dai, Junfeng, Yan, Yajun, Zhu, Bairen, He, Ruicong, Xie, Lu, Xu, Shijie, Chen, Xianhui, Yao, Wang, Cui, Xiaodong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.04.2013; Nature Publishing Group
• Subjects: 639/301/119; 639/301/119/1000; 639/766/119/1001; 639/766/119/995; Chalcogens - chemistry; Computer Simulation; Efficiency; Graphene; Humanities and Social Sciences; Light; Luminescence; Luminescent Measurements - methods; Materials Testing; Models, Chemical; multidisciplinary; Optical properties; Photons; Physics; Scattering, Radiation; Science; Semiconductors; Spin Labels; Splitting; Symmetry; Tungsten; Tungsten Compounds - chemistry

We report systematic optical studies of WS 2 and WSe 2 monolayers and multilayers. The efficiency of second harmonic generation shows a dramatic even-odd oscillation with the number of layers, consistent with the presence (absence) of inversion symmetry in even-layer (odd-layer). Photoluminescence (...