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Title: Two-dimensional semiconductor HfSe{sub 2} and MoSe{sub 2}/HfSe{sub 2} van der Waals heterostructures by molecular beam epitaxy

Using molecular beam epitaxy, atomically thin 2D semiconductor HfSe{sub 2} and MoSe{sub 2}/HfSe{sub 2} van der Waals heterostructures are grown on AlN(0001)/Si(111) substrates. Details of the electronic band structure of HfSe{sub 2} are imaged by in-situ angle resolved photoelectron spectroscopy indicating a high quality epitaxial layer. High-resolution surface tunneling microscopy supported by first principles calculations provides evidence of an ordered Se adlayer, which may be responsible for a reduction of the measured workfunction of HfSe{sub 2} compared to theoretical predictions. The latter reduction minimizes the workfunction difference between the HfSe{sub 2} and MoSe{sub 2} layers resulting in a small valence band offset of only 0.13 eV at the MoSe{sub 2}/HfSe{sub 2} heterointerface and a weak type II band alignment.
Authors:
; ; ; ; ; ; ; ;  [1]
  1. Institute of Nanoscience and Nanotechnology, National Center for Scientific Research “Demokritos,” 15310, Aghia Paraskevi, Athens (Greece)
Publication Date:
OSTI Identifier:
22398866
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 14; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM NITRIDES; COMPARATIVE EVALUATIONS; EV RANGE; HAFNIUM SELENIDES; HETEROJUNCTIONS; LAYERS; MICROSCOPY; MOLECULAR BEAM EPITAXY; MOLYBDENUM SELENIDES; PHOTOELECTRON SPECTROSCOPY; RESOLUTION; SEMICONDUCTOR MATERIALS; SUBSTRATES; SURFACES; TUNNEL EFFECT; TWO-DIMENSIONAL CALCULATIONS; TWO-DIMENSIONAL SYSTEMS; VALENCE; VAN DER WAALS FORCES