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Bright Blue Photo‐ and Electroluminescence from Eu 2+ ‐Doped GaN/SiO 2 Nanocomposites
Author(s) -
Mahalingam V.,
Tan M.,
Munusamy P.,
Gilroy J. B.,
Raudsepp M.,
van Veggel F. C. J. M.
Publication year - 2007
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200601236
Subject(s) - nanocomposite , europium , materials science , electroluminescence , doping , luminescence , excited state , quantum yield , electron paramagnetic resonance , photochemistry , optoelectronics , nanotechnology , optics , nuclear magnetic resonance , fluorescence , layer (electronics) , chemistry , atomic physics , physics
In this article we demonstrate the synthesis of Eu 2+ ‐doped GaN/SiO 2 nanocomposites using a simple solid state reaction and their use in light‐emitting devices. The nanocomposite exhibits a bright blue luminescence when excited in the UV region (quantum yield = 23 %). The origin of the blue emission is attributed to the presence of europium ions in the +2 oxidation state in the GaN/SiO 2 nanocomposites. Analysis of the EPR spectrum of europium‐doped GaN/SiO 2 nanocomposites confirms the existence of Eu 2+ in the nanocomposites. Various control experiments show that the blue emission arises from these europium ions and that the interface of GaN and silica plays a crucial role. The Eu 2+ ‐doped GaN/SiO 2 nanocomposite also exhibits a bright blue electroluminescence. Furthermore, the nanocomposites can be coated with a polymer to tune their dispersibility in organic medium.