Dislocation-enhanced spin relaxation in wurtzite GaN

By performing non-degenerate pump-probe experiments, we study the relaxation dynamics of spin-polarized excitons in wurtzite epitaxial gallium nitride (GaN). Characteristic times of the different spin-relaxation channel (electron, heavy- and light- or split-off-hole spin flips) for different samples as a function of temperature are extracted. We show that the high dislocation density increases the spin relaxation of electrons and holes through the defect-assisted Elliot–Yafet mechanism.