Optical Properties of ZnS:Mn²⁺ Yellow Nanophosphor Prepared by Spray Pyrolysis

Spray pyrolysis was used to prepare ZnS:Mn2+ yellow nanophosphor. As an increase in firing temperature for spray pyrolysis, more nanoparticles of a hexagonal phase were formed together with these of the cubic structure. The optimized emission intensity was observed when the nanophosphor was fired at 900 oC after using a spraying solution of 3.5 pH. The particle size ranged from 60 nm to 400 nm. The ZnS:Mn2+ nanophosphor showed a redshift of about 10 nm in the emission spectrum compared to the microphosphor synthesized by solid-state reaction. The temperature-dependence photoluminescence showed different spectroscopic behaviour and displayed a longer decay time than the microphosphor.