Size Dependence in Multicolor Upconversion in Single Yb3+, Er3+ Co-doped NaYF4 Nanocrystals

Peter A. Tanner, Chang-Kui Duan

Schietinger et al. (Nano Lett. 2009, 9, 2477-2481) observed single nanoparticle emission from NaYF4:Er3+,Yb3+ and noted unusual changes in the intensities of red and green emission…