Band Alignment in MoS2/WS2 Transition Metal Dichalcogenide Heterostructures Probed by Scanning Tunneling Microscopy and Spectroscopy.
Using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS), we examine the electronic structure of transition metal dichalcogenide heterostructures (TMDCHs) composed of monolayers of MoS2 and WS2. STS data are obtained for heterostructures of varying stacking configuration as well as the individual monolayers. Analysis of the tunneling spectra includes the influence of finite sample temperature, yield information about the quasi-particle bandgaps, and the band alignment of MoS2 and WS2. We report the band gaps of MoS2 (2.16 ± 0.04 eV) and WS2 (2.38 ± 0.06 eV) in the materials as measured on the heterostructure regions and the general type II band alignment for the heterostructure, which shows an interfacial band gap of 1.45 ± 0.06 eV.
Departments of Physics and Electrical Engineering, Columbia University , New York, New York 10027, United States.|Department of Applied Physics, Stanford University , Stanford, California 94305, United States.|SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, United States.
Heather M
HM
Hill
Departments of Physics and Electrical Engineering, Columbia University , New York, New York 10027, United States.|Department of Applied Physics, Stanford University , Stanford, California 94305, United States.|SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, United States.
Albert F
AF
Rigosi
Department of Chemistry, Columbia University , New York, New York 10027, United States.
Kwang Taeg
KT
Rim
Department of Chemistry, Columbia University , New York, New York 10027, United States.
George W
GW
Flynn
Departments of Physics and Electrical Engineering, Columbia University , New York, New York 10027, United States.|Department of Applied Physics, Stanford University , Stanford, California 94305, United States.|SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, United States.
Tony F
TF
Heinz
2D materials; heterostructures; scanning tunneling microscopy; scanning tunneling spectroscopy; transition metal dichalcogenides