Luminescence analysis of Mn4+,Zn2+: Li2TiO3 red phosphors

Publication date: February 2018
Source:Journal of Luminescence, Volume 194
Author(s): Fugui Yang, Liang Qiao, Haike Ren, Fengpo Yan
The Mn⁴⁺,Zn²⁺:Li2TiO3red phosphors are synthesized through the high temperature solid state reaction method. The XRD, SEM, ICP, absorption spectra, excitation and emission spectra are described. The Zn²⁺ acts as the luminescence adjustment ion to enhance the red emission efficiency. The phosphors have the crystal structure consisting of [TiO6] and [LiO6] octahedral sites and the Zn-O-Zn bonds. Concentration dependence on Zn²⁺ in Mn⁴⁺,Zn²⁺: Li2TiO3 is presented. Results indicate the suitable concentration of Zn²⁺ can enhance the emission efficiency. In the region of 682–697nm when excited by 475nm, the external quantum efficiency are obtained to be 18%, correlative with the transition of ²Eg (²T1)→⁴A2g of Mn⁴⁺. The crystal field strength (Dq) and the Racah parameters (B and C) are estimated to evaluate the nephelauxetic effect of Mn⁴⁺. The white-LED performances and thermal stability are also presented.



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