Up-conversion luminescence of Mn4+ sensitized byYb3+, Er3+ in NaMgGdTeO6

A series of NaMgGdTeO6: Yb3+/Er3+/Mn4+ phosphors have been prepared by a high-temperature solid-state reaction method. The as-prepared products exhibit typical deep red 696 nm emission of Mn4+ under 980 nm laser excitation, which is performed through the Yb3+/Er3+/Mn4+ multi-step energy transfers. The Yb3+, Er3+ and Mn4+ concentrations dependent up-conversion emission spectra, the Mn4+ concentration dependent Er3+ 544 nm emission lifetimes, and the pumping power and temperature dependent up-conversion luminescence intensities have been investigated in detail. The preliminary study in this work extends the up-conversion spectral range of the traditional up-conversion materials and provides reference for exploring new transition metal based up-conversion phosphors. (C) 2019 Elsevier B.V. All rights reserved.