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Indexed by:期刊论文

Date of Publication:2015-02-01

Journal:JOURNAL OF LUMINESCENCE

Included Journals:SCIE、EI

Volume:158

Page Number:211-214

ISSN No.:0022-2313

Key Words:ZnCoO/ZnMgO MQWs; PL; PL quenching; FRET

Abstract:Using a pulsed laser deposition system, ZnCoO/ZnMgO multiple quantum well (MQW) samples were grown on c-plane sapphire substrate with similar to 20.nm thick ZnO buffer layer. Compared with monolayer ZnCoO film, the MQW samples exhibited obviously enhanced Co2+ photoluminescence (PL) at similar to 1.80 eV and multiple-phonon resonant Raman scattering (RRS). The enhancement in multiple-phonon RRS was due to the introduction of ZnMgO barrier layer. The enhanced Co2+ PL was assigned to the quantum confinement effect (QCE) of MQW samples. However, QCE was found not helpful to prevent the band-gap PL quenching. Co2+ 3d electronic states were proved to be highly localized and a mechanism of fluorescence resonance energy transfer (FRET) between ZnO excitons and the localized Co2+ 3d states was proposed. (C) 2014 Elsevier B.V. All rights reserved.