Red emission from GaN nanocrystallite solids

The photoluminescence of the transparent GaN nanocrystallite solids is stud ied. Three new intensive isolated narrow red emission bands and one broad b lue band are observed. A mechanism to explain the origin of these bands is proposed. The three red bands may originate from the transitions of deep do nor levels to shallow accepters, while the blue band may be from the transi tions of shallow donors to deep levels with ground and excited states.