OPTICAL CHARACTERIZATION OF DISORDERED INXGA1-XP ALLOYS

We present results on the optical characterization of InxGa1-xP layers grown by atomic layer molecular beam epitaxy on GaAs (001) substrates at a growth temperature of 420 degrees C. Our results show that the o ptical characteristics of these layers, which do not show ordering eff ects, are strongly dependent on surface stoichiometry during growth. I n this way, we can obtain either highly homogeneous alloys with a pred ictable band-gap energy or layers with optical properties indicative o f spatial localization effects, like an anomalous behavior of photolum inescence peak energy with temperature and a large shift between the e mission energy and absorption edge. (C) 1998 American Institute of Phy sics.