Tunable emission properties of tri-doped Ca₉LiY_2/3（PO₄）₇:Ce³⁺,Tb³⁺,Mn²⁺ phosphors with warm white emitting based on energy transfer

Jindi Wang¹，Riyan Su²，Min Cui¹，Mengmeng Shang¹

1. School of Chemistry and Chemical Engineering,Qingdao University2. Shandong Academy of Environmental Sciences Co.

摘 要：Tri-doped Ca₉ LiY_2/3（PO₄）₇:Ce³⁺,Tb³⁺,Mn²⁺phosphors were prepared by a high-temperature solid state method.Under UV light excitation,Ca₉ LiY_2/3（PO₄）₇:Ce³⁺samples exhibit a broad band ranging from 320 to 500 nm.At 77 K,the emission spectra of Ca₉ LiY_2/3（PO₄）7:Ce³⁺samples present two obvious emission peaks,indicating that Ce³⁺ions occupy two different kinds of lattice sites（Ca（1/2） and Ca（3））,As a good sensitizer for Tb³⁺,Ce³⁺ions in Ca₉ LiY_2/3（PO₄）₇ lattice can effectively transfer part of energy to Tb³⁺,and the energy trans fer mechanism is determined to be dipole-dipole interaction.Consequently,the emitting color for Ce³⁺ and Tb³⁺ co-doped Ca₉ LiY_2/3（PO₄）₇ samples can be tuned from bluish violet to green.In order to further enlarge the emission gamut,Mn²⁺ions as red emission components were added,forming tri-doped single-phase Ca₉ LiY_2/3（PO₄）₇:Ce³⁺,Tb³⁺,Mn²⁺phosphors.The Ca₉ LiY_2/3（PO₄）₇:Ce³⁺,Tb³⁺,Mn²⁺phosphors exhibit tunable emission properties through controlling the relative doping concentration of Ce³⁺,Tb³⁺and Mn²⁺.Especially,Ca₉ LiY_2/3（PO₄）₇:0.09 Ce³⁺,0.12 Tb³⁺,0.30 Mn²⁺can emit warm white light.The sample shows good thermal stability.At 150℃,the emission intensity for Ce³⁺（360 nm）,Tb³⁺（545 nm） and Mn²⁺（655 nm） decreases to 63%,69%,and 72% of its initial intensity,respectively.Moreover,the sample obtains good stability after 10 cycles between room temperature and150℃.

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