Novel highly efficient blue-emitting SrHfSi2O7:Eu2+ phosphor: A potential color converter for WLEDs and FEDs

Abstract

A novel blue-emitting phosphor SrHfSi2O7: Eu2+ (SHSO: Eu2+) was designed and prepared via solid-state reaction, and the relationship between their crystal structure and luminescence properties were explored in detail. The structure and phase formation were determined by Rietveld refinements and transmission electron microscopy. Under excitation by n-UV light, the obtained samples have blue emission band with peaking at 456 nm. The dipole−dipole interaction is a dominant concentration quenching mechanism and the testing of fluorescence lifetimes proves the existing of energy transfer among Eu2+ ions. The phosphor shows moderate temperature dependence and, with substitution of 10% of Sr2+ by Ba2+, its thermal stability is noticeably improved. Besides, we fabricated a white LED lamp which can exhibit bright white light with a low color temperature of 4531 K and a high color rendering index of 90.2. Furthermore, under the excitation by low voltage electron, the phosphor will emit blue emission with high current saturation and resistance. All the results indicate that the SHSO: Eu2+ phosphor is a promising candidate for applying to both WLEDs and field emission displays.