Citric based sol-gel synthesis and luminescence characteristics of CaLa2ZnO5:Eu3+ phosphors for blue LED excited white LEDs

A novel class of orange-red phosphors namely CaLa2ZnO5 (CLZ) doped with Eu3+ ions were prepared by adopting citrate based sol-gel method. Those were thoroughly characterized by means of XRD, SEM, Tg-DTA, photoluminescent (PL) spectral profiles. PL studies reveal that its emission intensity strongly depends on sintering temperature as well as the dopant ion (Eu3+) concentration. Eu3+ ion doped CaLa2ZnO5 phosphor has a strong excitation at 468 nm, which correspond to the popular emission line from a GaN based blue light-emitting diode (LED) chip. The influence of the preparation method on the luminescence property was studied by comparing the emission performance of phosphors prepared by sol-gel and solid-state reaction methods along with a commercial red phosphor Y2O2S:Eu3+. Thus, the intense red emission (D-5(0)-> F-7(2)) of the Eu3+ doped CLZ phosphors under blue excitation suggests them to be a potential candidate for the production of white light by blue LEDs. (C) 2011 Elsevier B.V. All rights reserved.