Multiterminal Transport Measurements of Multilayer InSe Encapsulated by hBN

We investigate transport properties and scattering mechanisms of high-mobility InSe nanosheets, encapsulated by hBN, via four-terminal measurements. The measured conductivities increase as temperature (T) decreases, showing a metallic behavior at gate voltages above a threshold voltage, in contrast to the metal–insulator transition occurring at a high gate voltage observed in the two-terminal conductance of InSe. Phonon-limited and impurity-limited mobilities were separated for each carrier density (n) and T. Extracted impurity-limited mobility values are weakly dependent on n due to dominant short-range scatterers, while phonon-limited mobility values decrease as n increases due to second subband occupation and increased electron–phonon scattering.