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A theoretical study of the dependence of the AS x Si 6− x cluster structures and properties on composition
Author(s) -
Gao Aimei,
Li Guoliang,
Finlow David,
Chen Hongyu,
Li QianShu
Publication year - 2011
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.23111
Subject(s) - dissociation (chemistry) , silicon , cluster (spacecraft) , density functional theory , crystallite , chemistry , impurity , crystallography , binding energy , atom (system on chip) , alternation (linguistics) , polycrystalline silicon , atomic physics , computational chemistry , physics , linguistics , philosophy , organic chemistry , computer science , embedded system , programming language , electrode , thin film transistor
The effect of the composition ratio between arsenic and silicon atoms on the structures and properties of As x Si 6− x ( x = 0–6) have been systematically investigated using the density functional theory at the B3LYP/6‐311+G* level. The As x Si 6− x clusters prefer substitutional rather than attaching structures; the Si‐rich clusters favor Si 6 ‐like structures, whereas the As‐rich clusters prefer As 6 ‐like structures. The As atoms locating at the framework may explain the difficulty of removal of arsenic impurities from polycrystalline silicon. In general, the average binding energies gradually decrease, implying the As x Si 6− x clusters become increasingly unstable as x increases. Both the HOMO‐LUMO gaps and the As‐dissociation energies present a strong even–odd alternation, implying alternating chemical stability, with the even x members being more stable than the odd ones. The dissociation energies of an As atom from As x Si 6− x are: 3.07, 2.84, 1.84, 2.52, 1.86, and 2.85 eV, for x = 1–6, respectively, and 3.80, 3.08, 2.64, 3.01, 2.93, 3.16 eV for Si ( x = 0–5). These dissociation energy results should provide a useful reference for further experimental investigations. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012