LATTICE LOCATION AND OPTICAL-ACTIVITY OF YB IN III-V SEMICONDUCTING COMPOUNDS

The location of Yb atoms in indium (InP, Ga0.51In 0.49P) and gallium (GaAs, Al0.35Ga0.65As, GaAs0.6P0.4) III-V semiconducting compounds was investigated. It has been shown that Yb atoms occupy substitutional lattice positions only in indium compounds. Solid solubility of Yb in InP is of the order of 1020 cm-3, as estimated from Rutherford backscattering spectroscopy (RBS) measurements and is high by a factor of 2.5 than in 50% GaInP alloy. In gallium compounds the substitutional fraction of Yb is much below the detection limit of the RBS method, even in the case of elevated temperature (250 °C) implantation. It is suggested that optical activity of Yb is related to its substitutional location in the lattices and/or to the character of the YbP bond. The reasons for the material dependent behavior of Yb atoms in III-V crystal hosts are discussed.