Photoluminescence of three phonon replicas of the bound exciton in undoped InGaP prepared by liquid phase epitaxy

Photoluminescence and Raman spectroscopies are employed to study undoped InGaP layers grown on GaAs (100) substrates at 750 °C by liquid phase epitaxy. There are four peaks in the photoluminescence spectrum in the energy range between 1.55 and 2.25 eV. Besides a bound exciton recombination, three longitudinal optical phonon replicas with one superimposed donor-acceptor emission are identified based upon their dependences of emission energies on temperature and excitation intensity.