Selective enhancement of red upconvesion luminescence of Er3+ by doping with Mn2+ ions

Well-defined KZnF₃:Yb³⁺, Er³⁺, Mn²⁺ nanocubes were successfully prepared by a facile solvothermal method. The XRD and SEM measurements results show that the cubes have good crystallinity and the average cubic size is about 40 nm The incorporation of Mn²⁺ ions into KZnF₃:Yb³⁺, Er³⁺ leads to the great increase in the red to green luminescence intensity ratios from 10:1 to 214:1 and the red emission was enhanced about 20 times. The selective enhancement of red upconversion luminescence of Er³⁺ can be ascribed to the exchange energy transfer interactions between Er³⁺ ions and Yb³⁺-Mn²⁺ dimers. The case of KZnF₃:Yb³⁺, Er³⁺, Mn²⁺ provides a new strategy to get the pure red upconversion luminescence, which show potential applications in the fields of lighting, displays and biological nano labels.