Effect of isochronal annealing on photoluminescence properties of Mn-implanted GaN

Mn ions were implanted into metal organic chemical vapour deposition (MOCVD)-grown GaN with dose ranging from 10¹⁴ to 5×10¹⁶ cm⁻². Isochronal annealing at 800 and 850 °C has been carried out after implantation of the samples. Photoluminescence measurements were carried out on the implanted samples before and after annealing. A peak found at 3.34 eV in the spectra of implanted samples after annealing at 850 °C is attributed to the stacking faults. Blue and green luminescence bands have been observed suppressed and an oxygen-related peak appeared at 3.44 eV in the PL spectra. The suppression of blue and green luminescence bands has been assigned to dissociation of V_GaO_N complex. Near-band-edge (NBE) peak exhibited a blue shift after 800 °C anneal and then red shift to restore its original energy position when annealed at 850 °C.