Luminescence temperature and pressure studies of Zn₂SiO ₄ phosphors doped with Mn²⁺ and Eu³⁺ ions

Zn₂SiO₄:Mn²⁺, Zn₂SiO ₄:Eu³⁺ and Zn₂SiO₄:Mn ²⁺,Eu³⁺ phosphors were prepared by a sol-gel process and their luminescence spectra were investigated. The emission bands from intra-ion transitions of Mn²⁺ and Eu³⁺ samples were studied as a function of pressure. The pressure coefficient of Mn²⁺ emission was found to be -25.3±0.5 and -28.5±0.9 meV/GPa for Zn ₂SiO₄:Mn²⁺ and Zn₂SiO ₄:Mn²⁺,Eu³⁺, respectively. The Eu³⁺ emission shows only weak pressure dependence. The pressure dependences of the Mn²⁺ and Eu³⁺ emissions in Zn₂SiO ₄:Mn²⁺,Eu³⁺ are slightly different from that in Zn₂SiO₄:Mn²⁺ and Zn₂SiO ₄:Eu³⁺ samples, which can be attributed to the co-doping of Mn²⁺ and Eu³⁺ ions. The Mn²⁺ emission in the two samples, however, exhibits analogous temperature dependence and similar luminescence lifetimes, indicating no energy transfer from Mn²⁺ to Eu³⁺ occurs.