EVIDENCE OF COMPENSATING CENTERS AS ORIGIN OF YELLOW LUMINESCENCE IN GAN

The dependence of the near-band edge and the yellow luminescence in n- type GaN grown by organometallic vapor-phase epitaxy is investigated a s a function of doping concentration, The band edge and yellow lumines cence intensify increase as the doping concentration is increased. How ever, the band-edge-to-yellow luminescence ratio does not change signi ficantly as the doping concentration is increased by two orders of mag nitude. A theoretical model based on rate equations is developed for t he band-edge-to-yellow intensity ratio, Analysis of the experimental d ata in terms of the model reveals that the concentration of the level causing the yellow luminescence increases linearly with doping concent ration, This dependence shows that the yellow luminescence is due to a compensating center. (C) 1997 American Institute of Physics.