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Title: Optical constants and dynamic conductivities of single layer MoS{sub 2}, MoSe{sub 2}, and WSe{sub 2}

The complex optical constants of single layer MoS{sub 2}, MoSe{sub 2}, and WSe{sub 2} transition metal dichalcogenides (TMDCs) have been measured using concerted frequency-dependent transmittance and reflectance measurements. Absolute absorptivities as well as complex refractive indices and dielectric permittivities have been extracted. Comparisons to associated bulk responses reveal differences due to increased electron-hole interactions in single layer TMDCs. In parallel, corresponding complex optical conductivities (σ) have been determined. For MoS{sub 2}, extracted σ-values qualitatively agree with recent theoretical estimates. Significant differences exist, though, between experiment and theory regarding the imaginary part of σ. In all cases, the current approach distinguishes itself to other measurements of single layer TMDC optical constants in which it does not rely on Kramers-Kronig transformations of reflectance data.
Authors:
 [1] ;  [2] ;  [1]
  1. Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
  2. (Ukraine)
Publication Date:
OSTI Identifier:
22489172
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 8; 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; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTIVITY; CURRENTS; DIELECTRIC MATERIALS; FREQUENCY DEPENDENCE; HOLES; KRAMERS-KRONIG CORRELATION; MOLYBDENUM SELENIDES; MOLYBDENUM SULFIDES; PERMITTIVITY; REFRACTIVE INDEX; TRANSITION ELEMENTS