Synthesis and photoluminescence properties of La(Mg1-xNbx)O3:Mn4+ (x = 0.296 and 0.384) deep red-emitting phosphors

Abstract

In this work, we successfully synthesize La(Mg1-xNbx)O3:Mn4+ (x = 0.296 and 0.384) deep-red emitting phosphors by using high-temperature solid state method in air and investigate their crystal structures, morphologies, and luminescence properties. A broad excitation spectral band of La(Mg1-xNbx)O3:Mn4+ phosphors monitored at 705 nm can be observed in the region from 220 nm to 580 nm. La(Mg1-xNbx)O3:Mn4+ phosphors show a deep-red emission in the range of 640–760 nm with a peak at ~705 nm due to 2E → 4A2 transition of Mn4+ ions and the corresponding chromaticity coordinates are (0.7316, 0.22684). The concentration dependent emission spectra indicate that their optimal Mn4+ doping concentration is ~0.6 mol%. Their lifetime values decrease with increasing the Mn4+ doping concentration from 0.2 mol% to 1.0 mol%. The experimental results are helpful for the research on luminescence property of Mn4+ ions.