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Title: Vapor-transport growth of high optical quality WSe{sub 2} monolayers

Monolayer transition metal dichalcogenides are atomically thin direct-gap semiconductors that show a variety of novel electronic and optical properties with an optically accessible valley degree of freedom. While they are ideal materials for developing optical-driven valleytronics, the restrictions of exfoliated samples have limited exploration of their potential. Here, we present a physical vapor transport growth method for triangular WSe{sub 2} sheets of up to 30 μm in edge length on insulating SiO{sub 2} substrates. Characterization using atomic force microscopy and optical microscopy reveals that they are uniform, monolayer crystals. Low temperature photoluminescence shows well resolved and electrically tunable excitonic features similar to those in exfoliated samples, with substantial valley polarization and valley coherence. The monolayers grown using this method are therefore of high enough optical quality for routine use in the investigation of optoelectronics and valleytronics.
Authors:
 [1] ; ; ; ; ;  [2] ;  [1] ;  [3]
  1. Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195 (United States)
  2. Department of Physics, University of Washington, Seattle, Washington 98195 (United States)
  3. (United States)
Publication Date:
OSTI Identifier:
22303404
Resource Type:
Journal Article
Resource Relation:
Journal Name: APL Materials; Journal Volume: 2; Journal Issue: 10; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ATOMIC FORCE MICROSCOPY; CRYSTALS; DEGREES OF FREEDOM; OPTICAL MICROSCOPY; OPTICAL PROPERTIES; PHOTOLUMINESCENCE; POLARIZATION; SEMICONDUCTOR MATERIALS; SILICA; SILICON OXIDES; SUBSTRATES; TRANSITION ELEMENTS; VAPORS