Gas dependent hysteresis in MoS ₂ field effect transistors

Abstract

Abstract We study the effect of electric stress, gas pressure and gas type on the hysteresis in the transfer characteristics of monolayer molybdenum disulfide (MoS 2 ) field effect transistors. The presence of defects and point vacancies in the MoS 2 crystal structure facilitates the adsorption of oxygen, nitrogen, hydrogen or methane, which strongly affect the transistor electrical characteristics. Although the gas adsorption does not modify the conduction type, we demonstrate a correlation between hysteresis width and adsorption energy onto the MoS 2 surface. We show that hysteresis is controllable by pressure and/or gas type. Hysteresis features two well-separated current levels, especially when gases are stably adsorbed on the channel, which can be exploited in memory devices.