Research Article


2017, 10(2): 546–555


Anisotropic optical and electronic properties of twodimensional layered germanium sulfide

Dezhi Tan1 (*), Hong En Lim1, Feijiu Wang1, Nur Baizura Mohamed1, Shinichiro Mouri1, Wenjin Zhang1, Yuhei Miyauchi1, Mari Ohfuchi2, and Kazunari Matsuda1 (*)

View Author's information

1 Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
2 Fujitsu Laboratories Ltd., Atsugi 243-0197, Japan

Keywords: germanium sulfide, anisotropic optical property, 2D layered materials, photoluminescence, polarized optical spectroscopy
Full article PDF
Cite this article(Endnote)
Share this article

views: 125

Citations: 0

  • Abstract
  • References
  • Electronic Supplementary Material
ABSTRACT Two-dimensional (2D) layered materials, transition-metal dichalcogenides, and black phosphorus have attracted considerable interest from the viewpoints of fundamental physics and device applications. The establishment of new functionalities in anisotropic layered 2D materials is a challenging but rewarding frontier, owing to the remarkable optical properties of these materials and their prospects for new devices. Herein, we report the anisotropic and thicknessdependent optical properties of a 2D layered monochalcogenide of germanium sulfide (GeS). Three Raman-scattering peaks corresponding to the B3g, A1 g , and A2 g modes with a strong polarization dependence are demonstrated in the GeS flakes, which validates polarized Raman spectroscopy as an effective method for identifying the crystal orientation of anisotropic layered GeS. Photoluminescence (PL) is observed with a peak at ~1.66 eV that originates from the direct optical transition in GeS at room temperature. The polarization-dependent characteristics of the PL, which are revealed for the first time, along with the demonstration of anisotropic absorption, indicate an obvious anisotropic optical transition near the band edge of GeS, which is supported by density functional theory calculations. The significantly thickness-dependent PL is observed and discussed. This anisotropic layered GeS presents opportunities for the discovery of new physical phenomena and will find applications that exploit its anisotropic properties, such as polarization-sensitive photodetectors.
Related Article
Cite this article

Anisotropic optical and electronic properties of twodimensional layered germanium sulfide. Nano Res. 2017, 10(2): 546–555

Download citation