Dresden 2003 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 14: Poster I
HL 14.62: Poster
Montag, 24. März 2003, 17:00–19:30, HSZ/P2
Group-IV and group-V substitutional impurities in cubic group-III nitrides — •Luis E. Ramos, Jürgen Furthmüller, and Friedhelm Bechstedt — FSU-Jena IFTO Max-Wien-Platz,1 07743 Jena Deutschland
The substitutional group-IV (C, Ge, and Si) and group-V (P, As, and Sb) impurities are studied in cubic AlN and GaN for several charge states by means of ab initio ultrasoft pseudopotential calculations in density functional theory and local density approximation. The use of 216 simple-cubic supercells minimizes the impurity-impurity interaction due to the supercell method as well as the alloying effect inherent in small supercells for the treatment of impurities. We derive the trend of impurity levels in the fundamental gap with respect to the atomic number of the impurity and its energetical stability under several doping and preparation conditions. For each charged impurity, partial concentrations versus total concentration of incorporated impurities are calculated using the charge neutrality condition to determine the Fermi level. Our results address the search of new doping materials in the cubic phase of AlN, GaN and cubic AlxGa1−xN alloys.