The Mesoscale Regulation Of Beta-Nayf4:Yb3+/Er3+ With Desired Size And Morphology Via Introducing Li+/K+ Into A Hydrothermal Environment

Herein we report the controllable synthesis of NaYF4:Yb3+/Er(3+)via mesoscale regulation through the introduction of Li+/K+ into a hydrothermal system. The crystal evolution process of beta-NaYF4:Yb3+/Er3+ is investigated based on the reaction parameters. The mesoscale growth process includes four stages: (1) nucleation, (2) aggregation, (3) orientation growth, and (4) ripening. Through the introduction of Li+/K+ into the hydrothermal environment, super-small beta-NaYF4:Yb3+/Er3+ upconversion nanoparticles can be obtained.