Sensitization of luminescence of wurtzite GaN crystals doped with Eu and the additionally introduced Zn impurity

Abstract

A possibility to increase the intensity of intracenter transitions of the Eu ion in GaN crystals is investigated via introduction of the additional impurity to vary the local environment of the rare-earth ion. Wurtzite p-GaN crystals were initially doped with Mg and then with Eu. The introduction of the additional Zn impurity leads to a significant increase in the photoluminescence intensity in the range 3580–4250 A and the long-wavelength spectral range 5400–6237 A. This phenomenon can be attributed to the manifestation of sensitization of luminescence of optically active intracenter f-f transitions of the Eu3+ ion due to the introduction of the additional impurity, which promotes the formation of complexes of the rare-earth ion with a large capture cross-section of charge carriers.