Luminescence properties of green emission of SiO2/Zn2SiO4:Mn nanocomposite prepared by sol-gel method

K. Omri , J. El Ghoul , A. Alyamani , Carlos Barthou (1) , L. El Mir

1 INSP - Institut des Nanosciences de Paris

Green light emitting Mn2+ doped Zn2SiO4 particles embedded in SiO2 host matrix were synthesized by a sol-gel method. After the incorporation of ZnO:Mn nanoparticles in a silica monolith using sol-gel method with supercritical drying of ethyl alcohol in two steps, it was heat treated in air at 1200 degrees C for 2 h in order to obtain the SiO2/alpha-Zn2SiO4:Mn nanocomposites. The microstructure of phosphor crystals was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). XRD results indicate that the pure phase alpha-Zn2SiO4 with rhombohedral structure was obtained after thermal treatment at 1200 degrees C. The SiO2/alpha-Zn2SiO4:Mn nanocomposites with a Mn doping concentration of 1.5 at% exhibit two broadband emissions in the visible range: a strong green emission at around 525 nm and a second one in the range between 560 and 608 nm. This nanocomposite with a Mn doping concentration of 0.05 shows the highest relative emission intensity. Upon 255 nm excitation, the luminescence decay time of the green emission of Zn2SiO4:Mn around 525 nm is 11 ms. The luminescence spectra at 525 nm (T-4(1)-(6)A(1)) and lifetime of the excited state of Mn2+ ions-doped Zn2SiO4 nanocrystals are investigated. (C) 2013 Elsevier B.V. All rights reserved.

Mots clés: Zn2SiO4; Zinc oxide; Nanoparticle; Sol-gel; Optical material

Domaines: Matière Condensée [cond-mat]

K. Omri, J. El Ghoul, A. Alyamani, Carlos Barthou, L. El Mir. Luminescence properties of green emission of SiO2/Zn2SiO4:Mn nanocomposite prepared by sol-gel method. Physica E: Low-dimensional Systems and Nanostructures, 2013, 53, pp.48-54. ⟨10.1016/j.physe.2013.04.020⟩. ⟨hal-01236762⟩