Laser annealing towards high-performance monolayer MoS2 and WSe2 field effect transistors.

The transition metal dichalcogenides (TMDCs) have been intensively investigated as one of promising nanoelectronic and optoelectronic materials. However, the pervasive adsorbates on the surface of monolayer TMDCs, including oxygen and water molecules from the ambient environments, predominated degrade the device performance, in particular, under the cryogenic temperature, and the precise device application, such as gas sensor and ultrasensitive photodetectors. In this work, the effect of laser irradiation on the transport and photoresponse of monolayer MoS2 and WSe2 devices is investigated as a straightforward approach to remove the physically adsorbed contaminations. Compared with vacuum pumping and in-situ thermal annealing treatment, the field-effect transistors with the laser annealing show more than one order of magnitude higher on-state c.