Comparative Study on the Optical Properties of Eu:GaN with Tb:GaN

Abstract

Sharp luminescence originating from intra-atomic 4f–4f transition from both Eu and Tb doped GaN was observed at 622 nm which can be assigned to 5D0–7F2 transition of Eu3+ and at 545 nm which can be assigned to 5D4–7F5 transitions of Tb3+. However, the luminescence intensity of Eu3+ is two orders of magnitude stronger than that of Tb3+ though the content of the rare earth elements is almost the same. The cause of the difference in the luminescence properties was studied based on the defect-related energy transfer model, and the role of the defects observed by Fourier transform infrared (FTIR) spectra was discussed.