Critical synthesis parameters of β-phase Zn2SiO4:Mn2+ phosphor and its metastability

The metastable beta-phase Zn2SiO4:Mn2+ phosphor was successfully reproducible only under the following critical conditions: SiO2-rich stoichiometry, melting, and rapid cooling. The metastability of the beta-phase was demonstrated through the phase transformation of the as-grown beta-phase into the beta-phase polymorph by reannealing and then slowly cooling. The beta-phase showed yellow emission with a quantum efficiency of 65 %. The beta-phase has less crystalline structure caged into amorphous SiO2 phase and the more widely diffused larger grain sizes like a hexagonal shape of a snowflake. It showed the less thermal quenching behavior due to its lower lattice vibration, as well as the longer decay time due to less Mn2+ pairs.