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Title: Ab initio study on the effect of structural relaxation on the electronic and optical properties of P-doped Si nanocrystals

In contrast to the conventional doping of bulk silicon (Si), the doping of Si nanocrystals (NCs) that are often smaller than 5 nm in diameter may lead to serious structural changes. Since the electronic and optical properties of Si NCs are intimately associated with their structures, it is critical to understand how doping impacts the structures of Si NCs. By means of ab initio calculation we now compare 1.4 nm phosphorus (P)-doped Si NCs without structural relaxation and those with structural relaxation. Structural changes induced by structural relaxation are manifested by the stretching and compressing of bonds and apparent variations in bond angles. With the increase of the concentration of P structural changes induced by structural relaxation become more serious. It is found that structural relaxation makes differences in the energy-level schemes of P-doped Si NCs. Structural relaxation also causes the binding energy of an electron in a P-doped Si NC to more significantly increase as the concentration of P increases. With the increase of the concentration of P structural relaxation leads to more pronounced changes in the optical absorption of P-doped Si NCs.
Authors:
; ;  [1] ;  [2]
  1. State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China)
  2. IEMN-Department ISEN, UMR CNRS 8520, Lille 59046 (France)
Publication Date:
OSTI Identifier:
22402675
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 19; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; ABUNDANCE; BINDING ENERGY; BOND ANGLE; DOPED MATERIALS; ENERGY LEVELS; NANOSTRUCTURES; OPTICAL PROPERTIES; PHOSPHORUS; RELAXATION; SILICON