Origin of yellow luminescence from reduced pressure grown bulk GaN crystals

Abstract

Cathodoluminescence (CL) in the scanning electron microscope has been applied to study the luminescence emission of GaN single crystals grown by LPE methods. CL spectra show the presence of near band edge and of yellow emissions. The latter has been found to be mainly related to rows of hillocks formed at the growth steps. The origin of the yellow luminescence is discussed PACS: 78.60Hk; 71.55Eq.