Solvothermal synthesis and upconversion properties of about 10Â nm orthorhombic LuF3: Yb3+, Er3+ rectangular nanocrystals

Compared with YF3 and α-NaYF4 NCs, owning the similar size and the same doping levels of Yb3+ ions and Er3+ ions as LuF3 NCs, the green UC emission of LuF3 NCs is 18.7 times and 5.1 times stronger than that of YF3 and α-NaYF4 NCs respectively; the red UC emission of LuF3 NCs is 13.2 times and 0.6 times stronger than that of YF3 and α-NaYF4 NCs respectively.120