Gas dependent hysteresis in MoS ₂ field effect transistors

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.

Nanotip Contacts for Electric Transport and Field Emission Characterization of Ultrathin MoS2 Flakes

“…The exponential dependence of H W on the sweeping time [63], (time constant approximately 9 min), reveals a prevalent role of slow trap states related to either MoS 2 or SiO 2 defects compared to the contribution of MoS 2 defects or MoS 2 /SiO 2 interface (fast) traps [64,65]. These results are in agreement with previous experiments on similar devices contacted by Ti/Au (titanium/gold) metal contacts [6,66].…”

“…The obtained mobility is within the range (0.05 − 70 cm 2 V −1 s −1 ) commonly reported in FETs with a MoS 2 channel on SiO 2 [22,[59][60][61]. Its relatively low value can be caused partially by the high contact resistance but is mainly an indication of a high density of scattering centers, such as intrinsic defects in the crystal structure of MoS 2 , extrinsic traps at the MoS 2 /SiO 2 interface or into the SiO 2 dielectric layer, and charged impurities such as adsorbates on the MoS 2 surface [6].…”

“…Molybdenum disulfide (MoS 2 ) is one of the most studied members of the transition metal dichalcogenide family [1,2] as an alternative to graphene [3,4] for new-generation electronic devices and sensors based on atomically thin 2D materials. It has been extensively used to develop field effect transistors (FETs) [5,6], photodetectors [7], photovoltaic cells [8], light emitters [9], integrated circuits [10], field emission devices [11,12], and chemical [13] or biological [14] sensors.…”

Contact resistance and mobility in back-gate graphene transistors

“…The isolation of graphene [1][2][3] in 2004 and, later on, of h-BN [4], phosphorene [5], S Mo 2 [6][7][8][9][10][11][12][13][14], WSe 2 [15][16][17], e PdS 2 [18,19], PtSe 2 [20,21] etc, has strongly attracted the interest of the material science community to the world of two-dimensional (2D) materials.…”

Emerging 2D Materials and Their Van Der Waals Heterostructures

“…Tremendous amount of work has been done thus far on the physical and chemical properties as well as on the synthesis and the characterization of 2D materials such as graphene [13,14], transition metal chalcogenides [15,16] and dichalcogenides [17][18][19], hexagonal boron nitride [20], black phosphorus [21], organic perovskites [22], etc. Many of these materials have been used to fabricate stacked 2D-2D heterostructures [23], 2D-3D heterojunctions with common bulk semiconductors [24,25], or even 0D-2D and 1D-2D hybrids [26].…”