Photoluminescence study of rare-earth doped semiconductors under pressure

Abstract

High pressure photoluminescence (PL) studies are reported for InP:Yb and GaAs:Er, O. In InP:Yb, the thermally quenched intra-4f luminescence is recovered by applying pressure near room temperature. Simultaneously the band-edge related emission decreases. This result is interpreted qualitatively by a thermal equilibrium between the photocreated electron - hole pair of the host InP and the excited state of the 4f shell. In MOCVD grown GaAs:Er, O, the sharp luminescence from the intra-4f transition of Er is observed at 1.538 μm at atmospheric pressure. This is the main emission associated with the ErGa-2O center which has C2ν symmetry. For increasing pressure the PL intensity of the Er intra-4f emission increases and also some new PL lines appear at low temperatures. These pressure-induced new lines are assigned to other Er centers with different atomic configurations.