Red and green fluorescence of Mn2+ in NaCl

Abstract The fluorescence (emission and excitation) spectrum of Mn 2+ ion in NaCl has been investigated for freshly quenched samples (diluted Mn 2+ ions) and as grown samples (Mn 2+ ions forming aggregates and/or precipitates). Two main emission bands are generally observed in as grown samples, peaking at 505 nm and around 610 nm. Both emission bands are related to different manganese precipitates. Quenched samples show only the red emission but peaking at 605 nm and with a different excitation spectrum to that of the as grown crystals. Thus, this crystal is suitable to operate as a double color (red and green) emitting phosphor where the red and green relative intensities can be controlled by a thermal treatment.