Characterization and annealing of Eu-doped GaN

Red emission at 621 nm from the 5D0→7F2 transition of Eu+3 has been obtained from GaN:Eu grown by gas-source molecular beam epitaxy. The luminescence has been found to be more intense than the red emission from metalorganic chemical vapor deposition (MOCVD) derived AlGaAs. Upon annealing in both N2 and N2/H2 mixtures up to 800°C, the integrated photoluminescence (PL) intensity was found to remain within a factor of 2 of the as grown sample. The surface morphology also remained unchanged. Thermal quenching measurements of the as-grown sample saw a reduction in the 621 nm emission of 82% as the measurement temperature was increased from 20 to 300 K. The quenching was reduced to 66% after annealing at 800°C.