Properties of the yellow luminescence in undoped GaN epitaxial layers

Abstract

Photoluminescence, time-integrated, time-resolved, and photoluminescence excitation spectroscopy have been employed to study the 2.2 eV (``yellow'') emission in undoped GaN epitaxial layers. It is best described by a recombination model involving shallow donors and deep donors of probably intrinsic origin. Optically detected magnetic resonance reveals the participation of the shallow donor based on the analysis of the g value and Lorentzian line shape.