Tri-chromatic white-light emission from a single-phase Ca9Sc(PO4)7:Eu2+,Tb3+,Mn2+ phosphor for LED applications

Abstract

A series of single-phase Ca₉Sc(PO₄)₇:Eu²⁺,Tb³⁺,Mn²⁺ phosphors for UV excitations were synthesized by a high-temperature solid-state reaction. Energy transfer from Eu²⁺ → Tb³⁺ and Eu²⁺ → Mn²⁺ in a Ca₉Sc(PO₄)₇ sample is a feasible route to realize color-tunable emission because Ca₉Sc(PO₄)₇ single-doped Eu²⁺/Tb³⁺/Mn²⁺ emit blue, green and red light, respectively. Most of the white light region in the CIE chromaticity diagram has been realized in Ca₉Sc(PO₄)₇:Eu²⁺,Tb³⁺,Mn²⁺ phosphors. Warm white light including the points of (0.337, 0.331), (0.353, 0.355) and (0.358, 0.327) close to day light (0.33, 0.33) with CCT of 5285 K, 4719 K and 4333 K is obtained, respectively.