Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2015-02-01

Journal: JOURNAL OF LUMINESCENCE

Included Journals: EI、SCIE

Volume: 158

Page Number: 211-214

ISSN: 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.