Hydrogen Induced Yellow Luminescence in GaN Grown by Halide Vapor Phase Epitaxy

Abstract

Strong yellow luminescence (YL) was found in GaN grown by the halide vapor phase epitaxy technique, using an NH3-HCl-GaCl-N2-H2 growth chemistry. The low-temperature (less than 100K) thermal activation energy of the yellow luminescence was determined to be ∼18 meV, which indicates that a shallow donor, rather than a ‘shallow’ acceptor, was involved in observed radiative transition. The temperature dependence of the YL peak energy and the shape of the YL band imply that there are multiple recombination channels involved in the YL band. The ratio of integrated intensity of yellow-to-bandedge luminescence decreased with an increase of HCl (and hence GaCl and growth rate) in the growth ambient.