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Title: Excitonic optical properties of wurtzite ZnS quantum dots under pressure

By means of atomistic empirical pseudopotentials combined with a configuration interaction approach, we have studied the optical properties of wurtzite ZnS quantum dots in the presence of strong quantum confinement effects as a function of pressure. We find the pressure coefficients of quantum dots to be highly size-dependent and reduced by as much as 23% in comparison to the bulk value of 63 meV/GPa obtained from density functional theory calculations. The many-body excitonic effects on the quantum dot pressure coefficients are found to be marginal. The absolute gap deformation potential of quantum dots originates mainly from the energy change of the lowest unoccupied molecular orbital state. Finally, we find that the exciton spin-splitting increases nearly linearly as a function of applied pressure.
Authors:
; ;  [1] ;  [2]
  1. Materials Science Department, University of Patras, 26504 Patras (Greece)
  2. Institut für Physikalische Chemie, Universität Hamburg, 20146 Hamburg (Germany)
Publication Date:
OSTI Identifier:
22415534
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 11; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; COMPARATIVE EVALUATIONS; CONFIGURATION INTERACTION; CUBIC LATTICES; DEFORMATION; DENSITY FUNCTIONAL METHOD; EXCITONS; MANY-BODY PROBLEM; MOLECULAR ORBITAL METHOD; OPTICAL PROPERTIES; POTENTIALS; PRESSURE COEFFICIENT; PRESSURE DEPENDENCE; QUANTUM DOTS; ZINC SULFIDES