Fig. 5From: Excitation-Power-Dependent Upconversion Luminescence Competition in Single β-NaYbF4:Er Microcrystal Pumped at 808 nmThe proposed energy level diagram for a highly Yb3+-doped and b lowly Yb3+-doped β-NaYbF4:2%Er microcrystals, the corresponding mechanism of ET processes, radiative and non-radiative transitions are also providedBack to article page