PHOTOLUMINESCENCE OF INSB, INAS, AND INASSB GROWN BY ORGANOMETALLIC VAPOR-PHASE EPITAXY

Infrared photoluminescence (PL) from InSb, InAs, and InAs 1-xSbx (x<0.3) epitaxial layers grown by atmospheric pressure organometallic vapor phase epitaxy has been investigated for the first time over an extended temperature range. The values of full width at half maximum of the PL peaks show that the epitaxial layer quality is comparable to that grown by molecular-beam epitaxy. The observed small peak shift with temperature for most InAs1-xSbx epilayers may be explained by wave-vector-nonconserving transitions involved in the PL emission. For comparison, PL spectra from InSb/InSb and InAs/InAs show that the wave-vector-conserving mechanism is responsible for the PL emission. The temperature dependence of the energy band gaps, Eg, in InSb and InAs is shown to follow Varshni's equation Eg(T)=Eg0- αT2/ (T+β). The empirical constants are calculated to be Eg0=235 meV, α=0.270 meV/K, and β=106 K for InSb and Eg0=415 meV, α=0.276 meV/K, and β=83 K for InAs.