By analyzing time-resolved and steady-state photoluminescence spectra, it was established that the spatial distribution of rare-earth ion dopants in wurtzite GaN crystals doped with Sm, Eu, Er or Tm was governed by the type and concentration of defects in the initial semiconductor matrix as well as by the type of impurity (tendency to segregate). Doping with multi-charged rare-earth impurities and additionally introduced Zn impurity led to an intensification of the emissions. The effect of intensification of emission in the case of n-and p-GaN crystals was considered with the use of a model for iso-electronic traps.

Spatial Distribution of Defects and the Kinetics of Nonequilibrium Charge Carriers in GaN Wurtzite Crystals Doped with Sm, Eu, Er, Tm, and Supplementary Zn Impurities. M.M.Mezdrogina, V.V.Krivolapchuk, Y.V.Kozhanova: Semiconductors, 2008, 42[2], 159-72