Multilayer WS2 for low-power visible and near-infrared phototransistors
Aniello Pelella, Kimberly Intonti, O. Durante, Arun Kumar, Loredana Viscardi, S. De Stefano, P. Romano, Filippo Giubileo, Hazel Neill, Vilas Venunath Patil, Lida Ansari, Brendan Roycroft, Paul K. Hurley, Farzan Gity, Antonio Di Bartolomeo
Abstract
Abstract Mechanically exfoliated multilayer WS 2 flakes are used as the channel of field effect transistors for low-power photodetection in the visible and near-infrared (NIR) spectral range. The electrical characterization as a function of the temperature reveals devices with n-type conduction and slightly different Schottky barriers at the drain and source contacts. The WS 2 phototransistors can be operated in self-powered mode, yielding both a current and a voltage when exposed to light. The spectral photoresponse in the visible and the NIR ranges shows a high responsivity (4.5 μA/W) around 1250 nm, making the devices promising for telecommunication applications.