Synthesis of Er3+/Yb3+ codoped NaMnF3 nanocubes with single-band red upconversion luminescence

Abstract

We have developed a facile low-temperature synthetic method for the preparation of NaMnF₃ nanocubes with Er³⁺ and Yb³⁺ ions homogeneously incorporated in the host lattice. The effects of the reaction temperature, and the volume ratio between ethanol and DI water on the morphology of NaMnF₃ nanocubes are systematically investigated. The NaMnF₃ nanocubes can be produced in the low temperature range (25–80 °C), and the higher reaction temperature (80 °C) is favorable for the formation of a smooth surface. The formation of NaMnF₃ nanocubes strongly depends on the ethanol solvent. The morphology and single-phase of the obtained samples could be well maintained by controlling the doping concentration (Yb³⁺ ≤ 20 mol%). Single-band red upconversion emission can be generated in Er³⁺/Yb³⁺ codoped NaMnF₃ nanocubes due to the energy transfer between host Mn²⁺ and dopant Er³⁺ ions. It is revealed that our NaMnF₃:Er³⁺/Yb³⁺ nanocubes irradiate the brightest red luminescence at the dopant concentrations of Er³⁺ (2 mol%) and Yb³⁺ (15 mol%), which is stronger than that of the hexagonal-phase NaYF₄:Er³⁺/Yb³⁺ phosphor.