All-dry transferred single- and few-layer MoS2 field effect transistor with enhanced performance by thermal annealing

We report on the experimental demonstration of all-dry stamp transferred single-and few-layer (1L to 3L) molybdenum disulfide (MoS2) field effect transistors (FETs), with a significant enhancement of device performance by employing thermal annealing in moderate vacuum. Three orders of magnitude reduction in both contact and channel resistances have been attained via thermal annealing. We obtain a low contact resistance of 22 k Omega mu m after thermal annealing of 1L MoS2 FETs stamp-transferred onto gold (Au) contact electrodes. Furthermore, nearly two orders of magnitude enhancement of field effect mobility are also observed after thermal annealing. Finally, we employ Raman and photoluminescence measurements to reveal the phenomena of alloying or hybridization between 1L MoS2 all-and its contacting electrodes during annealing, which is responsible for attaining the low contact resistance. Published by AIP Publishing.