LAUSR

We explore an in situ doping method in chemical-vapor-deposited MoS2 thin films by the electron transfer from metallic MoOxSy particles embedded during thin film deposition. Analysis with transmission electron microscopy and Raman spectroscopy indicated amorphous MoOxSy particles embedded in MoS2 thin films. Analysis with x-ray photoelectron spectroscopy suggested stronger n-type doping effect in MoS2 thin films with increasing number of MoOxSy particles. Transfer length method measurement showed that contact resistance and resistivity of MoS2 thin films decrease with increasing number of MoOxSy particles. Transistors fabricated with MoS2 thin films further exhibited average field-effect mobility enhanced by 9 times along with negative shift of threshold voltage with increasing number of MoOxSy particles. These results demonstrate that in situ growth of MoOxSy in MoS2 thin films can be an alternative method of electron doping, providing the feasibility of using in situ doping methods for the device fabrication with MoS2 and other two-dimensional semiconductors.