Fig. 1From: Excitation-Power-Dependent Upconversion Luminescence Competition in Single β-NaYbF4:Er Microcrystal Pumped at 808 nma SEM images of the β-NaYF4:98%Yb,2%Er microcrystals. b The elements mapping of β-NaYF4:60%Yb,2%Er microcrystals. c XRD patterns of the β-NaYF4:x%Yb,2%Er microcrystalsBack to article page