Host-sensitized luminescence properties of KLa5O5(VO4)2:Eu3+ for solid-state lighting applications

Abstract

A novel KLa₅O₅(VO₄)₂ blue-emitting phosphor was synthesized and studied in this paper. The introduction of Eu³⁺ at various concentrations into the host crystal structure is possible through solid-state synthesis and was followed by X-ray diffraction. In this context, KLa₅O₅(VO₄)₂ can be considered as an excellent host matrix to develop new phosphors. In the present work, the luminescence properties of KLa_5−xEu_xO₅(VO₄)₂ (x = 0, 0.05, 0.1, 0.5, 1, 1.5 and 2) were investigated by fluorescence spectroscopy. The photoluminescence (PL) and PL excitation (PLE) spectra were recorded and discussed. KLa_5−xEu_xO₅(VO₄)₂ phosphors exhibit a bright reddish-orange light emission under UV excitation. The concentration quenching was determined to be at 20 mol% (x = 1) of Eu³⁺. The KLa₄EuO₅(VO₄)₂ phosphor cleverly substituted is an ideal candidate for solid-state lighting and especially, as a red phosphor for near-UV LEDs or to serve as the primary light source for white LEDs.