Rare-Earth Doped In1−xGaxP Prepared by Metalorganic Vapor Phase Epitaxy

ABSTRACTThe dependence of the luminescent properties of rare-earth impurities on the band structure of the host compound semiconductor has been investigated. Photoluminescence spectroscopy was used to characterize the optical properties of rare-earth doped Ini1−xGaxP layers prepared by metalorganic vapor phase epitaxy as a function of alloy composition. Thermal quenching of the Er3+, Yb3+, and Tm3+ related emission was observed over the temperature range of 15K to 360K with activation energies that depended on the alloy composition. From measurements of the thermally activated luminescence quenching, the energy levels of the isovalent erbium, ytterbium, and thulium in the alloys were determined. The variation of the position of the rare-earth related energy levels in the host semiconductor is explained in terms of a vacuum referred binding energy model that should have general applicability to other rare-earth doped semiconductor systems.