Microstructural properties of Eu-doped GaN luminescent powders

Abstract

GaN powders doped with europium have been prepared using Eu and Ga nitrates and N2H4 as reactants. The resulting particles have dimensions ranging from 0.5 to 1.0 μm. The crystalline structure was studied by transmission electron microscopy, and it consisted of single crystals with a hexagonal (wurtzite) structure containing small cubic domains (zinc blende) and a high density of stacking faults, all aligned along the [0001] and 〈111〉 directions, respectively. Cathodoluminescence measurements show strong light emission in the red region. This luminescence corresponds to transitions of Eu with the strongest emission in the 611 nm line, which is associated to the Eu3+ 4f transition from5D0 to7F2. These results demonstrate the feasibility of GaN:RE powders for luminescent applications.