Power-Dependent Optical Property of Yb/Er: NaGdF4@Yb: NaGdF4@Yb:NaNdF4 Nanocrystals

In most of the reports on nanocrystal (NC) luminescent, the power depedence of luminescent intensity is studied using a continuous-wave laser with low power density, and the slopes of those different emission bands keep unchanged. In this paper, the up/down conversion of monodisperse Yb/Er: NaGdF4@Yb: NaGdF4@Yb: NaNdF4 NCs under the excitation of 800[Formula: see text]nm femtosecond laser was detected simultaneously by a home-built optical measurement setup. The power-dependent optical properties under the excitation of femtosecond laser are quite different from the normal situation, which is due to their high peak power and energy transfer processes: Nd[Formula: see text].