Articles by Wei-Chu Shen in JoVE
Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures Ruei-San Chen1, Chih-Che Tang2, Wei-Chu Shen2, Ying-Sheng Huang2 1Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, 2Department of Electronic Engineering, National Taiwan University of Science and Technology We describe the approaches for the device fabrication and electrical characterization of molybdenum diselenide (MoSe2) layer semiconductor nanostructures with different thicknesses. In addition, the fabrication of ohmic contacts for MoSe2-layer nanocrystals by the focused-ion beam deposition method using platinum (Pt) as a contact metal is described.
Other articles by Wei-Chu Shen on PubMed
Thickness-dependent Electrical Conductivities and Ohmic Contacts in Transition Metal Dichalcogenides Multilayers Nanotechnology. Oct, 2014 | Pubmed ID: 25249412 We report on the observation of the substantial thickness (t)-dependent electrical conductivity (σ) at a wide thickness range for an MoSe₂ layer semiconductor. The conductivity increases for more than two orders of magnitude from 4.6 to 1500 Ω(-1) cm(-1) with a decrease in thickness from 2700 to 6 nm. The conductivity was found to follow a nearly linear relationship with the reciprocal thickness, i.e. σ ∝ 1/t. The temperature-dependent conductivity measurements also show that the MoSe₂ multilayers have much lower activation energies at 3.5-8.5 meV than those (36-38 meV) of their bulk counterparts, indicating the different origins of the majority carrier. These results imply the presence of higher surface conductivity or carrier surface accumulation in this layer crystal. The fabrication of ohmic contacts for the MoSe₂ layer nanocrystals using the focused-ion beam (FIB) technique was also demonstrated. This study provides a new understanding which is crucial for the development of flexible electronic devices and transparent conducting materials using ultrathin dichalcogenide layer materials.