KINETICS AND QUENCHING MECHANISMS OF PHOTOLUMINESCENCE IN YB-DOPED INP

The photoluminescence spectra of Yb-implanted InP samples were studied under pulsed and cw excitations using an Ar+-ion laser (above band-gap excitation) at different temperatures and excitation intensities. The photoluminescence spectrum of the 4f transitions F-2(5/2)-F-2(7/2) consists of a sharp peak at 1001 nm and broader peaks in the spectral range between 1002.5 and 1010 nm. Time-resolved spectra were recorded at different temperatures. Using a tunable Ti:sapphire laser (above and below band-gap excitation) the photoluminescence excitation spectra were investigated for different emission lines. Study of the rise and decay time under intrinsic excitation (band to band) show that the rise time is a function of excitation intensity, which reflects an indirect excitation process for Yb3+. The experimental data are explained using a kinetics model of energy transfer from the host lattice to the localized core excited states of rare-earth isoelectronic structured traps. The numerically simulated luminescence rise and decay times show a good general quantitative agreement with experimental data, over a wide range of generation rates. The photoluminescence spectra and decay time were also studied as a function of temperature. A quenching mechanism of ytterbium luminescence involving Yb and Fe ions is proposed. Finally, the electric-field quenching of InP:Yb photoluminescence is investigated.