Electronic Transport Properties in WSe2 Nanoflakes
Shih-Chieh Huang1*, Ruei-San Chen2, Liang -Chiun Chao1, Kuei-Yi Lee1
1Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan
2Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, Taiwan
* presenting author:Shih-Chieh Huang, email:andy811109121@yahoo.com.tw
The electrical properties in the single-crystalline tungsten diselenide (WSe2) two-dimensional (2D) nanostructures have been investigated. Those WSe2 nanosheets using mechanical exfoliation were found to exhibit higher conductivity and semiconducting properties, compared with their bulk counterparts. The single-crystalline quality and hexagonal structure of the WSe2 crystals were confirmed by Raman scattering and X-ray diffraction (XRD) measurements. Focused-ion beam (FIB) technique was used to fabricate the two-terminal devices. A low contact resistance was achieved according to the transmission line method. Temperature-dependent measurement also indicates much lower carrier activation energy of the WSe2 nanoflakes compared to that of the bulks. In addition, photoconductive properties in the WSe2 nanostructures and bulks by the excitation of the wavelength of 532 nm were also investigated.

Keywords: tungsten diselenide, nanosheet, conductivity