Transport Study of Charge-Carrier Scattering in Monolayer WSe2

Employing flux-grown single crystal ${\mathrm{WSe}}_{2}$, we report charge-carrier scattering behaviors measured in $h$-BN encapsulated monolayer field effect transistors. We observe a nonmonotonic change of transport mobility as a function of hole density in the degenerately doped sample, which can be explained by energy dependent scattering amplitude of strong defects calculated using the T-matrix approximation. Utilizing long mean-free path ($>500\text{ }\text{ }\mathrm{nm}$), we also demonstrate the high quality of our electronic devices by showing quantized conductance steps from an electrostatically defined quantum point contact, showing the potential for creating ultrahigh quality quantum optoelectronic devices based on atomically thin semiconductors.