標題: Complex Optical Conductivity of Two-Dimensional MoS2 : A Striking Layer Dependency
作者: Song, Baokun
Gu, Honggang
Fang, Mingsheng
Ho, Yen-Teng
Chen, Xiuguo
Jiang, Hao
Liu, Shiyuan
材料科學與工程學系
Department of Materials Science and Engineering
公開日期: 17-Oct-2019
摘要: The complex optical conductivities of two-dimensaionl (2D) materials are fundamental for extended applications of related optoelectronic devices. Here, we systematically investigate the layer-dependent evolutions in the complex optical conductivities of 1-6 layer 2D MoS2 over an ultrawide spectral range (0.73-6.42 eV) by spectroscopic ellipsometry. We identify five feature peaks (A-E) in the optical conductivity spectra, which present interesting layer dependencies due to the scaling effect. Results suggest that the center energies of peaks A and B are nearly layer-independent, while those of peaks C and D exhibit redshifts as the layer increases. We interpret these layer-dependent evolutions as the competition between the decreasing exciton effect and the prominent band shrinkage with the increasing layer number. Additionally, the applicability of the classical slab model and the surface current model in evaluating the optical conductivities of 2D MoS2 with different layers is discussed from an experimental perspective.
URI: http://dx.doi.org/10.1021/acs.jpclett.9b02111
http://hdl.handle.net/11536/153179
ISSN: 1948-7185
DOI: 10.1021/acs.jpclett.9b02111
期刊: JOURNAL OF PHYSICAL CHEMISTRY LETTERS
Volume: 10
Issue: 20
起始頁: 6246
結束頁: 6252
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