Reactive-ion-etched gallium nitride: Metastable defects and yellow luminescence

Abstract

Gallium nitride has been reactive-ion etched with SF6 and argon plasmas. The Ar-etched samples show a striking transition from a dominant blue luminescence band to a dominant yellow luminescence band after less than 5 min of low power illumination. The observation of metastable defects which are associated with both the yellow and blue bands has important consequences for our understanding of defect-related luminescence in gallium nitride.