The impact of Yb3+ concentration on multiband upconversion in single NaYF4:Yb/Er microcrystal determined via nanosecond time-resolved spectroscopy

In lanthanide-sensitized upconversion (UC) nanomaterials, the typical sensitizer Yb3+ can significantly modulate the codoped activator (such as Er3+ ions) to generate multiband transitions. However, the kinetics of these multiband emissions...