Preparation and luminescent characteristics of Eu3+-activated MgxZn1-xGa2O4 nanocrystals

Nanometer-scale Eu-doped MgxZn1-xGa2O4 phosphorpowders have been synthesized by sol-gel process. The crystallization behaviors were investigated as well as the excitation and photoluminescence spectra employed to study the luminescence properties of Eu3+ in Mg-Zn mixed gallate. The grain size gradually decreases from 32.5 to 8.6 nm as Mg content increases. The excitation spectrum varies with the composition and consists of a weak charge transfer band and intense f-f transitions. Under the excitation at 394nm, the Eu-doped MgxZn1-xGa2O4 phosphors display strong red luminescence at about 612nm belonging to D-5(0) -> F-7(2) electric dipole transition. Both the emission intensity and life-time increase with the arising concentration of Mg. (c) 2005 Elsevier B.V. All rights reserved.