Open AccessElectronic Properties and Scanning Tunneling Microscopy Simulation of MoS2 Nanosheets by Using Density Functional Theory
Author(s) -
Farzana Ahmed,
Alamgir Kabir
Publication year - 2021
Publication title -
the dhaka university journal of science
Language(s) - English
Resource type - Journals
eISSN - 2408-8528
pISSN - 1022-2502
DOI - 10.3329/dujs.v69i1.54624
Subject(s) - scanning tunneling microscope , density functional theory , nanosheet , band gap , van der waals force , scanning tunneling spectroscopy , materials science , atom (system on chip) , ab initio , electronic structure , nanotechnology , condensed matter physics , chemical physics , molecular physics , chemistry , computational chemistry , optoelectronics , molecule , physics , organic chemistry , computer science , embedded system
The ab-initio Density Functional Theory (DFT) approach is used to study the electronic properties of bulk and layered MoS2 nanosheets. For the layered structures mono, bi, tri, tetra and penta layered structure is used. The direct to indirect transition of bandgap is observed as the number of layers is increasing. This transition of bandgap is attributed to the van der Waals interlayer interaction between two layers of MoS2 nanosheets. The indirect bandgap in the bulk MoS2 is found to be 0.94 eV, whereas for a single layered nanosheet is found to be direct bandgap with the value of 1.83 eV. To confirm the surface termination and understand the surface morphology of MoS2 the scanning tunneling microscopy (STM) simulation is performed in constant height mode. It is found that the detection of surface atoms via STM depends on the tip atom of the STM.
Dhaka Univ. J. Sci. 69(1): 53-57, 2021 (January)