(Invited) Performance Limit and Potential of Layered MoTe2 Transistors

Abstract

Atomically thin flaks were obtained to fabricate field-effect transistors by using mechanical exfoliation of 2H-type α-molybdenum ditelluride (MoTe2) bulk crystal grown by chemical vapor transport. Both static and dynamic charge transport of these layered transistors were systematically investigated to explore the underlying mechanism of charge transport. In the quasi-static measurements, carrier ambipolarity was observed and originated from the formation of tunable Schottky barriers at the metal/MoTe2 contacts. In the dynamic measurements, .the 1/f dependence of the noise was observed in the conducting channels in vacuum and followed the carrier number fluctuation model. Moreover, the noise spectrum in ambient conditions changed to a Lorentzian, possibly because a large number of gas molecules absorbed at the chalcogen vacancies, enhancing the trapping and emission of carriers between two discrete energy states. Using such unique layered transistors, we further realized complementary-like inverters, amplifiers and environmental sensors, demonstrating their feasibility for future digital and analog circuit applications.