Electronic Transport Properties in GaS Two-dimensional Nanostructures
C. M. Chen (陳家茂)1*, R. S. Chen (陳瑞山)2, H. P. Hsu (許宏彬)1, C.H. Ho (何清華)2
1Department of Electronic Engineering, Ming Chi University of Technology, Taipei, Taiwan
2Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, Taiwan
* presenting author:陳家茂, email:m02158011@mail2.mcut.edu.tw
We report the electronic transport properties in the III–VI layer semiconductor of gallium sulfide (GaS) with different thicknesses grown by the chemical vapor transport (CVT). The GaS layer nanostructure devices were fabricated using focused-ion beam (FIB) deposition and platinum (Pt) as the contact metal.The single-crystalline quality and hexagonal structure of the GaS crystals were confirmed by Raman scattering and X-ray diffraction (XRD) measurements. The electrical characterization result shows that the conductivity values (0.4 to 261 Ω-1cm-1) of the GaS nanostructures with the thickness range from 10 to 404 nm are five to seven orders of magnitude higher than those of the bulk counterparts. A roughly thickness-dependent conductivity behavior was also observed for the GaS layer nanostructures. The activation energy for the majority carrier was estimated to be lower than 18 meV by the temperature-dependent conductivity measurement. The probable physical origins leading to the difference of electrical properties in the GaS nanostructure and bulk crystal are also discussed.

Keywords: gallium sulfide, layer semiconductor, conductivity