Electrical and optical characterization of atomically thin WS2

Atomically thin layers of materials, which are just a few atoms in thickness, present an attractive option for future electronic devices. Herein we characterize, optically and electronically, atomically thin tungsten disulphide (WS2), a layered semiconductor. We provide the distinctive Raman and photoluminescence signatures for single layers, and prepare field-effect transistors where atomically thin WS2 serves as the conductive channel. The transistors present mobilities mu = 10 cm(2) V-1 s(-1) and exhibit ON/OFF ratios exceeding 100 000. Our results show that WS2 is an attractive option for applications in electronic and optoelectronic devices and pave the way for further studies in this two-dimensional material.