Codoped Tb3+ and Mn2+ induced tunable emission and energy transfer in Ca19Zn2(PO4)14:Ce3+,Tb3+,Mn2+

Abstract

To explore a new phosphor, Ca₁₉Zn₂(PO₄)₁₄:Ce³⁺,Tb³⁺ and Ca₁₉Zn₂(PO₄)₁₄:Ce³⁺,Mn²⁺ phosphors are successfully synthesized with the objective of application in ultraviolet-based light-emitting diodes. X-ray diffraction (XRD), photoluminescence (PL) spectra, and lifetimes were used to characterize the samples. Under UV excitation, the energy transfer from the Ce³⁺ to Tb³⁺ ions in the Ca₁₉Zn₂(PO₄)₁₄ host occurred mainly via a dipole–quadrupole mechanism, and the critical distances of the ion pairs (R_C) were calculated by the spectral overlap method. A bright red light emission was observed in the Ce³⁺ and Mn²⁺ codoped samples via the energy transfer from the sensitizer Ce³⁺ to Mn²⁺ ions. With an appropriate ratio of the active ion concentrations, the Ce³⁺, Tb³⁺ and Ce³⁺,Mn²⁺ codoped Ca₁₉Zn₂(PO₄)₁₄ phosphors can generate light from the blue to green and blue to orange regions, respectively. The emission colors of the phosphors were also clarified by CIE coordinates briefly.