Fig. 3From: Excitation-Power-Dependent Upconversion Luminescence Competition in Single β-NaYbF4:Er Microcrystal Pumped at 808 nmThe ratios of R/G for single a β-NaYF4:98%Yb,2%Er, and b β-NaYF4:20%Yb,2%Er microcrystal as a function of the excitation intensity. The dependences of the UCL intensity on the excitation intensity for single c β-NaYF4:98%Yb,2%Er, and d β-NaYF4:20%Yb,2%Er microcrystal. All excitation wavelengths are at ~ 808 nmBack to article page