Near-infrared emission from MnO2-4 in various host lattices

We have doped MnO2-4 into the host lattices K2MO4 (M = S, Cr, Se), Cs2SO4 and BaMO4 (M = S, Cr, Se, Mo). Broadband spontaneous emission between 11000 and 7000 cm−1 is observed in all crystals upon visible or near-infrared photoexcitation. The Mn6+ emission persists up to room temperature with an estimated quantum efficiency of 20% in BaSO4: Mn. A correlation is established between the temperature quenching behaviour and the size of the host ion M6+ for which Mn6+ substitutes: the quenching increases with increasing radius of M6+.