Vacancy defects as compensating centers in Mg-doped GaN.
We apply positron annihilation spectroscopy to identify V(N)-Mg(Ga) complexes as native defects in Mg-doped GaN. These defects dissociate in postgrowth annealings at 500-800 degrees C. We conclude that V(N)-Mg(Ga) complexes contribute to the electrical compensation of Mg as well as the activation of p-type conductivity in the annealing. The observation of V(N)-Mg(Ga) complexes confirms that vacancy defects in either the N or Ga sublattice are abundant in GaN at any position of the Fermi level during growth, as predicted previously by theoretical calculations.
Hautakangas
S
S
Laboratory of Physics, Helsinki University of Technology, FIN-02150 Espoo, Finland.
Oila
J
J
Alatalo
M
M
Saarinen
K
K
Liszkay
L
L
Seghier
D
D
Gislason
H P
HP