First principle defect study of MoSe2 field effect transistor

Abstract

the TMD-based devices [6][7][8][9]. This has resulted in the demonstration of devices (MOSFET) based on MoS 2 monolayer in which various short channel effects can be observed easily such as negative differential resistance (NDR) in the armchair(ANR) nanoribbon which has encouraged the device studies based on other TMD materials. MoSe 2 being one of the most promising materials among them.Despite all the robustness to the short channel effects, in two-dimensional ribbons such as graphene, silicene, germacrene and monolayer MoSe 2 , there are many minor thermodynamic defects and deformations like wrap, twist and crumpling [10][11][12]. Small magnitude of these defects can alter the behavior of MoSe 2 armchair nanoribbon channel thus affecting the performance of MoSe 2 -MOSFET device in terms of charge transport properties like transmission spectrum, band gap and the NDR characteristics. So studying the effect of these defects on the NDR behavior could be worthwhile.In this study, we have investigated the effect of several defects and deformations such as rough edge, twist, wrap and ripple on the performance of a 6-nm-channel length and 1-nm-width MoSe 2 ANR MOSFET. Moving on, we have also simulated the current-voltage (I-V) characteristics of MoSe 2 -MOSFET using a density functional tightbinding theory combined with non-equilibrium Green's function theory. In particular, we have studied the effect of these defects on the NDR behavior of MoSe 2 device and various parameters associated with it like PVR (peak-tovalley ratio). ModelWe used a MoSe 2 ANR nanoribbon as our channel material for the ANR MOSFET device with length 6 nm and Abstract In this study, we have investigated the impact of various defects and deformations such as rough edge, twist, wrap (tube) and ripple on the NDR (negative differential resistance) behavior of a MoSe 2 armchair (ANR) MOSFET. We have studied the current voltage characteristics of the device under these deformations along with the transmission spectrum of the ANR channel. Change in the NDR region and peak-to-valley ratio has been observed for each deformation, and significant changes were observed in each case.