White-light emitting Eu³⁺ co-doped ZnO/Zn₂SiO₄:Mn²⁺ composite microphosphor

Eu(3+) co-doped ZnO/Zn2SiO4:Mn(2+) composites were synthesized via conventional solid state reaction route and were characterized by X-ray diffraction (XRD) scanning electron microscopy (SEM) and Fourier transform infra-red (FTIR) techniques. XRD studies reveal the presence of both ZnO and Zn2SiO4 phases. Photoluminescence properties of the samples were studied using 266 Nd-YAG laser excitations. Emission bands observed at ~400 nm are ascribed to ZnO phosphor. The green emission bands at 530 nm is associated with the presence of Mn(2+) ion, while orange (~583) and red (615 nm) bands are supposed to be due to the presence of Eu(3+) doped Zn2SiO4 phosphor. Energy transfer from power dependence of the sample for electric dipole transition (615 nm) was studied under 532 nm excitation by varying the power from 0.1 to 4.5 W. The estimated colour correlated temperature (CCT) values are found to be ~4875 and 4458 K under 266 nm and 532 nm laser (0.5 W) excitations. These values are close to those of tubular fluorescent or cool white/daylight compact fluorescent (CFL) (~5000 K) lamps. The present composite phosphor may have potential application in display devices.