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Keywords:

  • doping;
  • europium;
  • GaN;
  • photoluminescence;
  • powder;
  • rare earths

Abstract

The red emission properties of Eu doped gallium nitride (GaN) powder prepared by a Na flux method were characterized by time-resolved photoluminescence (PL) and site-selective PL excitation studies. Under above-gap excitation (325 nm), Eu3+ doped GaN powders exhibited bright red luminescence at ∼622 nm (5D0[RIGHTWARDS ARROW]7F2 transition). The room-temperature emission lifetime was determined to be ∼242 µs and increased only slightly at 10 K with a value of ∼252 µs. At the same time, the integrated Eu3+ PL intensity was quenched by a factor of ∼20 for the temperature range from 10 to 300 K. Low temperature PL excitation studies in the region of the 7F0[RIGHTWARDS ARROW]5D0 transition of Eu3+ ions indicated the existence of multiple Eu3+ centers with distinct excitation and emission properties in GaN:Eu powder.