Crystal structure, luminescence properties, energy transfer, tunable occupation and thermal properties of a novel color-tunable phosphor NaBa1−zSrzB9O15:xCe3+,yMn2+

Abstract

A series of color-tunable NaBa_1−zSr_zB₉O₁₅:Ce³⁺,Mn²⁺ phosphors were synthesized by a high temperature solid state method. Luminescence property, energy transfer, thermal stability and cation substitution were investigated in detail. Due to energy transfer, NaBaB₉O₁₅:Ce³⁺,Mn²⁺ presents violet to green luminescence and manifest a broad excitation range from 200 to 350 nm. The energy transfer mechanism of Ce³⁺–Mn²⁺ is identified as a dipole–dipole interaction. NaBa_1−zSr_zB₉O₁₅:Ce³⁺,Mn²⁺ displays both Ce³⁺ violet and Mn²⁺ green and orange emissions under ultraviolet excitation. It is observed that Sr²⁺ partial substitution for Ba²⁺ could adjust the ratio of Mn²⁺ emission intensity in different cation sites, which results from preferred sites’ occupation with modification of the crystal structure. Furthermore, increase in temperature can enhance the energy transfer from Ce³⁺ to Mn²⁺, which enhances the Mn²⁺ emission intensity sharply. The highly thermal-sensitive property of NaBa_1−zSr_zB₉O₁₅:Ce³⁺,Mn²⁺ makes it feasible for its potential application in luminescent ratiometric thermometers with wide temperature range.