A Novel Orange-Red Emitting ZnB4O7:Eu3+Phosphor with Urchin-Like Nanostructure

Abstract

A novel phosphor, ZnB4O7:Eu3+, with urchin-like structure consisting of radially arranged high density nanorods was successfully synthesized by hydrothermal process at 150°C for 24 h. The nanorods were measured from 200 to 400 nm in diameter and severalµm in length. The urchins were fewµm to 40 µm in diameter. The ZnB4O7:Eu3+phosphors were efficiently excited by ultraviolet (UV ~ 254 nm) to visible light of ~ 220 to 450 nm and exhibited intense orange-red emission consisting of main peaks at 590, 615, and 695 nm due to the charge transfer in the host andf→ftransitions (5D0to7F1,2,4) of the Eu3+ions. Effect of the Eu3+ions concentration on the photoluminescence (PL) emission intensity was investigated and it was found that 5 at% Eu3+is the optimum concentration. Meanwhile, the concentration quenching mechanism was discussed. The key parameters, such as temperature dependent PL and CIE values of ZnB4O7:Eu3+phosphors, were studied. The ZnB4O7:Eu3+phosphor exhibited good thermal stability and better absorption cross section compared to the commercial Y2O2S:Eu3+phosphor. All these characteristics indicate that the phosphor will be a potential candidate for the UV based white LEDs.