Relaxation mechanism of Yb 4f-shell in InP

Comparison of the temperature dependencies of the intra-4f-shell photoluminescence (PL) and free electron concentration in Yb-doped InP reveals that two mechanisms dominate the thermal quenching of this PL. One is the localized Auger effect, which is effective in samples with an excess donor concentration. The other mechanism is independent of n- and p-type impurities and has an activation energy of about 150 meV. Investigation of the relationship between the temperature dependencies of the band-edge related PL and the 4f-shell PL indicates that this is due to the energy back transfer from the Yb 4f-shell to the host electronic state.<
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