Green/red photoluminescence emission in γ-Zn3(PO4)2:Mn2+/Ga3+ for applications in ultraviolet-light emitting diodes

► The γ-Zn3(PO4)2:Mn2+, Ga3+ gives the green/red emission spectra. ► The ratio of the green to the red varies following the Ga3+ concentration. ► The energy transfer occurs between the Mn2+ (CN = 4) to Mn2+ (CN = 6). ► Energy transfer and the effect of Ga3+ determine the emission spectra.