Effects of activated Sr 2+ ion content on strong blue‐emitting Ca 2 Sb 2 O 7 materials for high‐quality WLED devices

Abstract

In this report, the luminescent performances of the self-host blue-emitting Ca2Sb2O7 materials were investigated in terms of the sintering temperature and the dopant Sr2+ ion content. The emission intensity was enhanced with an increase of the sintering temperature as well as the lattice parameters. After doping the Sr2+ ions (>1.2 mol%), the emission spectra of Ca2Sb2O7 materials would be redshifted. The blue-emitting color (Ca2Sb2O7) turned into greenish-blue (Sr2+@1.6 mol%) and green (Sr2+@2 mol%) colors in sequence. In light of these interesting findings, the crystal structure, elemental composition, morphology, thermal stability, luminescent dynamics, luminescent efficiency, etc were investigated and compared. Finally, the mini-white lighting-emitting diodes (WLEDs) based on the blue-emitting Ca2Sb2O7, greenish-blue-emitting Ca0.4Sr1.6Sb2O7, and green-emitting Sr2Sb2O7 phosphors were fabricated by mixing commercial phosphors (CP). Especially, the Ca2Sb2O7-CP-WLED and Sr2Sb2O7-CP-WLED devices exhibited a warm white light with good correlated color temperature (<3200 K) and excellent color-rendering index (>88). All the above results suggested that the self-host emitting materials of Sr2+ activated Ca2Sb2O7 with color-tunable properties could be very promising for solid-state lighting applications.