Tunable multicolor luminescent properties of Ca8ZnLa(PO4)7:Ce3+, Mn2+ phosphor via efficient energy transfer

Abstract

A series of single doped (Ce3+) and co-doped (Ce3+ and Mn2+) Ca8ZnLa(PO4)7 (CZLP) phosphors are synthesized in air by using the solid-state reaction method. The crystal structure, morphology, and luminescence properties of the samples are investigated. The blue emission of CZLP:Ce3+ phosphors is observed in the range of 325–450 nm when they are excited by 315 nm ultraviolet (UV) light, and the optimal Ce3+ concentration is about 8 mol%. With excitation at 315 nm, a tunable color emission of CZLP:8%Ce3+, yMn2+ phosphors from blue to red is displayed when Mn2+ concentration is changed from 0 to 12 mol%, and the corresponding chromaticity coordinates are varied from (0.1635, 0.0118) to (0.5885, 0.2829). The spectral propertires and lifetimes confirm the energy transfer (ET) process from Ce3+ to Mn2+ ions in CZLP:8%Ce3+, Mn2+ phosphor. The luminous mechanism and ET phenomenon are explained by using the Tanabe-Sugano diagram of Mn2+ ion and the energy level diagrams of Ce3+ and Mn2+ ions. The experimental results are favorable for the improving and adjusting of luminescence properties of other phosphors.