Synthesis and Luminescence Properties of Sr/SmSi₅N₈:Eu²⁺Phosphor for White Light-Emitting-Diode

Abstract

Red-emitting nitride phosphors recently attracted considerable attention because of their high thermal stability and high color rendering index properties. For excellent phosphor of white light-emitting-diode, ternary nitride phosphor of Sr/SmSi 5 N 8 :Eu 2+ with different Eu 2+ ion concentration were synthesized by solid state reaction method. In this work, red-emitting nitride Sr/SmSi 5 N 8 :Eu 2+ phosphor was successfully synthesized by using multi-step high frequency induction heat treatment. The effects of molar ratio of component and experimental conditions on luminescence property of prepared phosphors have been investigated. The structure and luminescence properties of prepared Sr/SmSi 5 N 8 :Eu 2+ phosphors were investigated by XRD and photoluminescence spectroscopy. The excitation spectra of Sr/SmSi 5 N 8 :Eu 2+ phosphors indicated broad excitation wavelength range of 300 -550 nm, namely from UV to visible area with distinct enhanced emission peaks. With an increase of Eu 2+ ion concentration, the peak position of emission in spectra was red-shifted from 613 to 671 nm. After via multi-step heat treatment, prepared phosphor showed excellent luminescence properties, such as high emission intensity and low thermal quenching, better than commercial phosphor of Y 3 Al 5 O 12 :Ce 3+. Using Eu 2 O 3 as a raw material for Eu 2+ dopant with nitrogen gas flowing instead of using commercial EuN chemical for Sr/SmSi 5 N 8 :Eu 2+ synthesis is one of characteristic of this work.