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Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
Published on: December 5, 2015
Optical Duality of Molybdenum Disulfide: Metal and Semiconductor
Wonkil Sakong, Hamza Zad Gul1, Byungwook Ahn
1Department of Electrical Engineering, Namal University, 30 Km Talagang Road, Mianwali 42250, Pakistan.
Abstract:
The two different light-matter interactions between visible and infrared light are not switchable because control mechanisms have not been elucidated so far, which restricts the effective spectral range in light-sensing devices. In this study, modulation of the effective spectral range is demonstrated using the metal-insulator transition of MoS2. Nondegenerate MoS2 exhibits a photoconductive effect in detecting visible light. In contrast, degenerate MoS2 responds only to mid-infrared (not visible) light by displaying a photoinduced heating effect via free carrier absorption. Depending on the doping level, the optical behavior of MoS2 simulates the photoconductivity of either the semiconductor or the metal, further indicating that the optical metal-insulator transition is coherent with its electrical counterpart. The electrical switchability of MoS2 enables the development of an unprecedented and novel design optical sensor that can detect both visible and mid-IR (wavelength of 9.6 μm) ranges with a singular optoelectronic device.
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