243: Variation in photoluminescence properties of substituted calcium zinc vanadate garnet phosphors

Abstract: Rare-earth-free vanadate phosphors are promising materials for solid-state lighting due to their broad visible emission from V-O charge-transfer transitions. In this project, the photoluminescence and structural properties of Ca2.5Zn2(VO4)3 (CZV), a vanadate phosphor with a garnet crystal structure, were characterized in samples with varied concentrations of Na substituted for Ca and P substituted for V. Samples were synthesized using a citrate gel-combustion method. Normalized emission spectra showed that all substituted and undoped samples emitted near 505-510 nm. Emission band width and intensity varied with concentration, along with colorimetric properties. The emission bands were observed with increasing substitution level. Excitation spectra exhibited more pronounced peak shifts with varied concentration than did emission spectra, with peak excitation ranging from 340-370 nm. A systematic blue shift with increased substitution was observed, along with varied quantum and absorption efficiency in the violet spectral region.