Photoluminescence (PL) spectra, luminescence dynamics and luminescence saturation of the Er3+
4I13/2 → 4I15/2 transition in Er-implanted GaN samples at 7K are investigated. Under below-gap excitation, different Er centers are identified. Several Er centers are clearly excited via local defects or impurities. Er-defect complexes excited by above or below bandgap light are compared. Luminescence dynamics study shows that the 4I13/2 manifold has a shorter lifetime when Er ions are part of Er-defect complexes than when Er ions are isolated from any defect. The saturation of Er luminescence is investigated for the different types of Er center corresponding to specific excitation wavelengths.