Calculated properties of point defects in Be-doped GaN
Latham, CD, Nieminen, RM, Fall, CJ, Jones, R, Öberg, S and Briddon, PR (2003) Calculated properties of point defects in Be-doped GaN Physical Review B: Condensed Matter and Materials Physics, 67 (20), 205206.
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The properties of several point defects in hexagonal gallium nitride that can compensate beryllium shallow acceptors (BeGa) are calculated using the AIMPRO method based on local density functional theory. BeGa itself is predicted to have local vibrational modes (LVM’s) very similar to magnesium acceptors. The highest frequency is about 663cm-1. Consistent with other recent studies, we find that interstitial beryllium double donors and single-donor beryllium split interstitial pairs at gallium sites are very likely causes of compensation. The calculations predict that the split interstitial pairs possess three main LVM’s at about 1041, 789, and 738cm-1. Of these, the highest is very close to the experimental observation in Be-doped GaN. Although an oxygen donor at the nearest-neighboring site to a beryllium acceptor (BeGa-ON) is also a prime suspect among defects that are possibly responsible for compensation, its highest frequency is calculated to be about 699cm-1 and hence is not related in any way to the observed center. Another mode for this defect is estimated to be about 523cm-1 and is localized on the ON atom. These two vibrations of BeGa-ON are thus equivalent to those for the isolated substitutional centers perturbed by the presence of their impurity partners.
|Divisions :||Faculty of Engineering and Physical Sciences > Chemistry|
|Date :||15 May 2003|
|Identification Number :||10.1103/PhysRevB.67.205206|
|Related URLs :|
|Additional Information :||Copyright 2003 The American Physical Society.|
|Depositing User :||Symplectic Elements|
|Date Deposited :||14 Dec 2012 12:36|
|Last Modified :||23 Sep 2013 19:54|
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