Luminescence and Electroluminescence of Nd, Tm and Yb Doped GaAs and some II-Vicompounds

摘要

This report describes the progress accomplished during the three years ofresearch on photoluminescence and electroluminescence properties of Nd, Tm, Yb doped, InP, GaAs, CdS, and ZnS. The results are as follow: (1) We developed the kinetics model of energy transfer from the host lattice to the localized core excited state of rare earth isoelectronic structured traps. The energy transfer processes occur through an Auger mechanism where the recombination energy of the bound electron with a free hole is transferred nonradiatively to the core states, (or energy can be transferred from the bound exciton on an REI-trap to the core states). If the initial and final states are not resonant, the energy mismatch must be accommodated by emission or absorption of phonons. Furthermore we discuss details of several quenching processes, which are incorporated into the kinetics equations. The derived two sets of differential equations for semi-insulating, and n type semiconductors governing the kinetics of rare earth luminescence. The numerically simulated luminescence rise and decay times show a good quantitative agreement with experimental data obtained for InP: Yb, over a wide range of excitation intensity. The photoluminescence spectra and decay time were also studied as a function of temperature. The new quenching mechanism of ytterbium luminescence involving Yb and Fe ions is proposed. The electric field quenching of InP: Yb photoluminescence was investigated for the first time. (2) The photoluminescence kinetics as a function of excitation intensity in n and p type InP: Yb, and GaAs: Nd grown by MOCVD was studied at 1.8 K and 77 K.