HIGHLY EXCITED LUMINESCENCE IN INGAN EPITAXIAL-FILMS - ORIGINS OF THEBLUE-GREEN EMISSION

Luminescence dynamics of Si-doped InxGa1-xN epitaxial films has been s tudied by means of time-resolved luminescence spectroscopy at low temp erature. Under the band-to-band excitation the recombination dynamics shows a typical model of exciton localization in ternary alloyed mixed crystals and/or donor-induced luminescence centers. With the increase of the excitation density the sharp luminescence band appears from th e high-energy side of the luminescence peak. The sharp peak shifts to the low-energy side as time proceeds. The observed feature can neither be explained by the usual models of biexciton nor by a electron-hole plasma. (C) 1998 Elsevier Science B.V. All rights reserved.