Tuning the upconversion luminescence of cubic KMnF3:Yb3+/Er3+ nanocrystals through inert lanthanide ion doping

Efficient tailoring of upconversion emissions in conventional single red emitting KMnF₃:Yb³⁺/Er³⁺ nanocrystals is achieved through local crystal structure engineering and the suppression of energy transfer as well as back transfer, which is of great significance for extended optical applications.