Exploring the surface-to-volume ratio in ultrasmall nanocrystals using the optical probe of Eu3+ ion

We demonstrate fine control of the nanocrystal size of ultrasmall Eu3+-doped Sc2O3 nanocrystals within an extremely small nanometer scale from 2.6 to 9.7 nm, thereby enabling us to thoroughly investigate the size-dependent surface-to-volume ratio in these ultrasmall NCs using an optical probe of the red-emitting Eu3+ ion for the first time.