HYDROGEN-INDUCED YELLOW LUMINESCENCE IN GAN GROWN BY HALIDE VAPOR-PHASE EPITAXY

Strong yellow luminescence (YL) was found in GaN grown by the halide v apor phase epitaxy technique, using an NH3-HCl-GaCl-N-2-H-2 growth che mistry. The low-temperature (less than 100K) thermal activation energy of the yellow luminescence was determined to be similar to 18 meV, wh ich indicates that a shallow donor, rather than a 'shallow' acceptor, was involved in observed radiative transition. The temperature depende nce of the YL peak energy and the shape of the YL band imply that ther e are multiple recombination channels involved in the YL band. The rat io of integrated intensity of yellow-to-bandedge luminescence decrease d with an increase of HCl (and hence GaCl and growth rate) in the grow th ambient.