摘要

Monodisperse beta-NaYF4:Ln(3+) (Ln = Yb/Er, Yb/Tm) single micro/nanocrystals were first one-pot fabricated at 50 degrees C through a novel synthetic route containing two pivotal processes: (a) synthesis of a beta-NaYF4 {0001} unit layer through a novel style of ion-exchange from Y-2(OH)(5)NO3 center dot nH(2)O (LYH) and (b) the subsequent oriented-assembly process.