A novel orange-red phosphor Ca₃B₂O₆:Sm³⁺, A⁺(A = Li, Na, K) for white light emitting diodes

Abstract

A novel orange-red phosphor Ca 3 B 2 O 6 : Sm 3+ , A + ( A = Li , Na , K ) has been synthesized by solid-state reaction at 950°C. The phase purity and photoluminescence (PL) behavior of the phosphor are studied in detail using the powder X-ray diffraction (XRD) technique and PL measurements. Ca 3 B 2 O 6 : Sm 3+ phosphor can be efficiently excited by near ultraviolet (n-UV) and blue light, and the emission spectrum consists of four emission peaks at 563, 599, 646 and 709 nm, generating bright orange-red light. When a cation A + is introduced into Ca 3 B 2 O 6 : Sm 3+ as charge compensator, the emission intensity of Ca 3 B 2 O 6 : Sm 3+ is evidently enhanced, but the PL spectral profile is unchanged. The integral intensity of the emission spectrum of Ca 2.96 Sm 0.02 Na 0.02 B 2 O 6 excited at 401 nm is about 1.2 times than that of Y 2 O 2 S : Eu 3+ commercial red phosphor. The CIE chromaticity coordinates of Ca 2.96 Sm 0.02 Na 0.02 B 2 O 6 phosphor were (0.608, 0.365), which are close to that of the commercial red phosphors Y 2 O 3 : Eu 3+ (0.655, 0.345), Y 2 O 2 S : Eu 3+ (0.622, 0.351) and Sr 2 Si 5 N 8 : Eu 2+ (0.620, 0.370).