DYNAMICAL STUDY OF THE YELLOW LUMINESCENCE BAND IN GAN

A comprehensive study of the yellow photoluminescence (YL) in GaN epit axial films grown by hydrid vapor phase epitaxy and by metal organic v apor phase epitaxy is presented including time-integrated and time-res olved photoluminescence (PL), PL excitation (PLE) and optically detect ed magnetic resonance (ODMR) experiments. ODMR reveals the participati on of shallow and deep double donors based on the analysis of the g-va lues. This recombination model is supported by time-resolved investiga tions. PLE spectra show a close connection between the excitation proc esses of the YL band and of the inner transition of Fe3+ at 1.293 eV. Two-color stimulation experiments prove energy transfer between YL and the Fe3+ center by hole transfer, strongly confirming the YL recombin ation model involving a deep level 1.2 eV above the valence band. (C) 1997 Elsevier Science Ltd.