Effect of Si codoping on Eu3+ luminescence in GaN

Eu and Si codoped GaN thin films were grown on sapphire by solid source molecular beam epitaxy. Eu3+ photoluminescence (PL) emission at ∼622 nm (D50-F72) was enhanced by approximately five to ten times with Si doping. The effect of Si codoping on PL intensity, lifetime, and excitation dependence revealed two distinct regimes. Moderate Si doping levels (0.04–0.07 at. %) lead to an increase in lifetime combined with improved excitation efficiency and a greatly enhanced PL intensity. High Si doping levels (0.08–0.1 at. %) significantly quench the PL intensity and lifetime, due primarily to nonradiative channels produced by a high defect population.