Particle size dependence of the dynamic photophysical properties of NaYF4:Yb, Er nanocrystals

The effects of the nanocrystal size on the emission spectra and decay rates of upconverting hexagonal NaYF4:Yb, Er nanocrystals are investigated. The influence of nanocrystal size is represented in terms of the surface area/volume ratio (SA/Vol). Our results show that a small nanocrystal size, or large SA/Vol ratio increases the decay rate, in particular, the green luminescence decay rate varies linearly with the SA/Vol ratio. (C) 2009 Optical Society of America