Determination of acceptor concentration in GaN from photoluminescence

The concentration of the acceptor responsible for the yellow luminescence (YL) band at about 2.2 eV in GaN is determined from photoluminescence. The YL band intensity increases linearly with excitation power density and partially saturates above some critical value. The dependence is quantitatively described within a phenomenological model accounting for recombination statistics in GaN layer and saturation of acceptors with photogenerated holes. The incomplete saturation of the YL intensity at high excitation intensities is explained by gradual saturation of acceptors at different distances from the sample surface. The identity of deep and shallow acceptors in GaN is discussed. (c) 2006 American Institute of Physics.