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

摘要

A novel phosphor, ZnB4O7:Eu3+, with urchin-like structure consisting of radially arranged high density nanorods was successfully synthesized by hydrothermal process at 150 degrees C for 24 h. The nanorods were measured from 200 to 400 nm in diameter and several mu m in length. The urchins were few mu m to 40 mu m in diameter. The ZnB4O7:Eu3+ phosphors were efficiently excited by ultraviolet (UV similar to 254 nm) to visible light of similar to 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 and f -> f transitions (D-5(0) to F-7(1,2,4)) 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.