Several transition metal dichalcogenides are semiconductors which, similarly to graphene, are composed of van der Waals coupled atomic layers. When exfoliated down to a single atomic layer, a transition from an indirect to a direct band gap is observed suggesting their suitability for electronics and optoelectronics. In fact, several classes of high-performance devices have already been reported along with significant progress in understanding their physical properties. Here, we will provide a very brief overview on the field and discuss experimental studies which further unravel their potential for optoelectronic applications. In particular, we will discuss initial results on mutilayered WSe2 field-effect transistors which indicate extremely high photoresponsivities, i.e. in excess of ~7 A/W, along with photo response times ranging from t ~5 ms to 40 ms, which are promising values for photo detecting applications. ....... All these observations underline the particularly strong interaction between light and charge carriers in these systems.
Host: Prof. Younjung Jo