Radiation damage mechanisms for luminescence in Eu-doped GaN

Abstract

Thin films of Eu-doped GaN were irradiated with 500keV He+ ions to understand radiation damage mechanisms and to quantify luminescence efficiency. The dependence of ion-beam-induced luminescence intensity on ion fluence was consistent with the simultaneous creation of nonradiative defects and the destruction of luminescent centers associated with 4f-4f core-level transitions in Eu3+. This model contrasts with a previous description which takes into account only nonradiative defect generation in GaN:Eu. Based on light from a BaF2 scintillator standard, the luminescent energy generation efficiency of GaN:Eu films doped to ∼3×1018cm−3 Eu is estimated to be ∼0.1%.