Carrier relaxation dynamics for As defects in GaN

Long decay times in the 50-150 ns range have been measured for the characte ristic blue photoluminescence that peaks at 2.6 eV in GaN:As. We interpret these long decay times according to the theoretical predictions that this b lue photoluminescence is caused by the incorporation of arsenic on the gall ium site. The long decay times are characteristics of the large lattice rel axation for such a deep donor with a negative-U center behavior. (C) 2001 A merican Institute of Physics.