LUMINESCENCE FROM AL0.28GA0.72AS0.62P0.38 LAYERS GROWN ON GAAS0.61P0.39 SUBSTRATES BY LIQUID-PHASE EPITAXY

High quality Al0.28Ga0.72As0.62P0.38 layers were grown on GaAs0.61P0.39 epitaxial substrates by liquid-phase epitaxy using a supercooling technique. The electrical properties of the AlGaAsP layers were determined by capacitance-voltage measurements at 300K. The undoped layers always give n-type conduction with a background concentration of 1 X 10(16) cm-3. The 9-K photoluminescence spectra show three distinctive peaks and their relative intensities change with the excitation power density. The temperature dependence of photoluminescence from the undoped AlGaAsP layers shows that there is a new peak emerging above 30K. The four major emission peaks have been identified, involving intrinsic recombination, donor-to-valence-band transitions, conduction-band-to-acceptor transitions, and donor-acceptor pair transitions. The binding energies of the residual donors and acceptors are 13.7 and 36 meV, respectively, nevertheless these impurites are not completely identified.