Gas dependent hysteresis in MoS ₂ field effect transistors

Abstract

We study the effect of electric stress, gas pressure and gas type on the\nhysteresis in the transfer characteristics of monolayer molybdenum disulfide\n(MoS2) field effect transistors. The presence of defects and point vacancies in\nthe MoS2 crystal structure facilitates the adsorption of oxygen, nitrogen,\nhydrogen or methane, which strongly affect the transistor electrical\ncharacteristics. Although the gas adsorption does not modify the conduction\ntype, we demonstrate a correlation between hysteresis width and adsorption\nenergy onto the MoS2 surface. We show that hysteresis is controllable by\npressure and/or gas type. Hysteresis features two well-separated current\nlevels, especially when gases are stably adsorbed on the channel, which can be\nexploited in memory devices.\n