2024/09/05 by Santu Prasad Jana, Jana, Santu Prasad, Suraina Gupta +3
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Semiconductor materials and interfaces #Surface and Thin Film Phenomena
paper · pdf · doi:10.48550/arxiv.2409.03304
openalex publication_date 2024/09/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Randomly distributed traps at the MoS2/SiO2 interface result in non-ideal transport behavior, including hysteresis in MoS2/SiO2 field effect transistors (FETs). Thus traps are mostly detrimental to the FET performance but they also offer some application potential. Our STM/S measurements on atomically resolved few-layer and single-layer MoS2 on SiO2 show n-doped behavior with the expected band gap close to 2.0 and 1.4 eV, respectively. The local tunnel conductance with gate-voltage V\rm g sweep exhibits a turn-on/off at a threshold V\rm g at which the tip's Fermi-energy nearly coincides with the local conduction band minimum. This threshold value is found to depend on V\rm g sweep direction amounting to local hysteresis. The hysteresis is, expectedly, found to depend on both the extent and rate of V\rm g-sweep. Further, the spatial variation in the local V\rm g threshold and the details of tunnel conductance Vs V\rm g behavior indicate inhomogenieties in both the traps' density and their energy distribution. The latter even leads to the pinning of the local Fermi energy in some regions. Further, some rare locations exhibit a p-doping with both p and n-type V\rm g-thresholds in local conductance and an unusual hysteresis.