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

TL;DR

This paper clarifies that previously observed size-dependent emission changes in NaYF4:Er3+,Yb3+ nanocrystals are artifacts, correcting misconceptions about the underlying physics of upconversion luminescence.

Contribution

The study demonstrates that reported size-dependent emission variations are due to instrumental artifacts, providing a corrected understanding of upconversion in these nanocrystals.

Findings

Size-dependent emission changes are artifacts, not physical effects.

Instrumental factors can mislead interpretation of nanocrystal luminescence.

Corrected understanding impacts future nanocrystal design.

Abstract

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 emissions with particle size. We show that the documented changes are due to instrumental artifacts and that the explanations given for the changes are incorrect.