Amphoteric arsenic in GaN

Abstract

The authors have determined the lattice location of implanted arsenic in GaN by means of conversion electron emission channeling from radioactive As73. 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 AsGa "antisites" are not minority defects provide additional aspects to be taken into account for an explanantion of the so-called miscibility gap in ternary Ga As1-x Nx compounds, which cannot be grown with a single phase for values of x in the range of 0.1