Synthesis and luminescence of sub-micron sized Ca 3Sc 2Si 3O 12:Ce green phosphors for white light-emitting diode and field-emission display applications

Abstract

Ca 3Sc 2Si 3O 12:Ce 3+ phosphors with sub-micron size were successfully synthesized by a gel-combustion method. The crystal structure and morphology of the phosphors and their photoluminescence were investigated. The results indicate that the pure phase of Ca 3Sc 2Si 3O 12 can be obtained at 1100 °C of firing temperature. The particles of phosphor are basically spherical in shape with the mean size less than 1 μm. The grain of the phosphor grows up gradually with the increasing of the firing temperature. The excitation spectrum shows a broad and strong absorption band centered around 450 nm, compatible with the excited wavelength of commercial blue light-emitting diode (LED) for white LED lighting. Bright green-emission located at 505 nm is observed and the intensity of the green-emission increases with the increase of firing temperature. Additionally, under low-voltage (2.5 kV) excitation of electron beam, bright green cathodoluminescence (CL) is also observed, which is attributed to the characteristic emission from Ce 3+. Our work suggests that Ca 3Sc 2Si 3O 12:Ce 3+ phosphors are promising for both white LED and field-emission display applications.