Amphoteric arsenic in GaN

The authors have determined the lattice location of implanted arsenic in GaN by means of conversion electron emission channeling from radioactive As-73. They give direct evidence that As is an amphoteric impurity, thus settling the long-standing question as to whether it prefers cation or anion sites in GaN. The amphoteric character of As and the fact that As-Ga antisites are not minority defects provide additional aspects to be taken into account for an explanantion of the so-called miscibility gap in ternary GaAs1-xNx compounds, which cannot be grown with a single phase for values of x in the range of 0.1 < x < 0.99. (C) 2007 American Institute of Physics.