EXCITONS AND ELECTRON PHONON INTERACTION IN IN0.52GA0.18AL0.30AS LAYERS

Temperature dependent photoreflectance, photoluminescence, and Raman spectroscopy have been used to study the optical properties of MBE-grown InGaAlAs layers lattice matched to InP. A detailed study of the photoreflectance and photoluminescence spectra at low temperatures gives an exciton binding energy of the order of 2 meV. At higher temperatures, a combination of temperature dependent photoluminescence and Raman measurements indicates that InAs-like LO phonons play a dominant role in the electron-phonon interaction of these crystals.