Temperature dependent and time-resolved photoluminescence (PL) studies were performed on the red emission properties of Eu doped GaN powders prepared by a Na flux method. The Eu~(3+) doped GaN powder showed bright red emission (～622 nm) at room temperature, which corresponds to the intra-4f Eu~(3+) transition ~5Do→ ~7F_2. It was observed that under above-gap excitation the integrated Eu~(3+) PL intensity was quenched by a factor of ～20 for the temperature range 10 to 300 K. In contrast, the emission lifetime was only slightly temperature dependent with an average value of ～242 μs at room temperature. Photoluminescence excitation (PLE) measurements performed in the visible spectral region revealed a weak defect-related and broad excitation band superimposed by narrow intra-4f absorption lines of Eu~(3+) ions. Moreover, PLE studies for the ~5F_0→ ~7D_0 transition demonstrated the existence of multiple Eu~(3+) centers in the investigated GaN powder.
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