Spectral and luminescence properties of manganese ions in vitreous lead metaphosphate

Optical materials doped with manganese ions have attracted interest as a red phosphor for warm white light LEDs. Lead-phosphate glasses are chosen for doping with manganese ions due to high refractive index of such material. In this study, new 50 PbO - 50 P2O5 - xMnO2 (x = 0.1, 1, 3, 5, 7, 10, 13 mol%) glasses are synthesized. To determine the optimal manganese ion concentration (to be used as the red phosphor) in those glasses, their spectral and luminescent properties are investigated. Mn2+ ions in lead-phosphate glasses have intense red luminescence in the wavelength range 620-690 nm. The Mn3+ ion to the total Mn ions ratio is found less than 0.1% based on the visible absorption spectroscopy data. Manganese ions in that glass are disposed at non-equivalent positions that results in nonexponential lifetime decay. The maximum absolute quantum yield value of Mn2+ ions is 49% in glass with 2.91 mol% MnO2.