Lanthanide-doped KYb3F10 crystals: controllable phases, rich morphologies and Tb3+/Eu3+ down-conversion emission†
Abstract
KYb3F10:Ln3+ (Ln = Er, Ho, Tb, Gd, Eu, Sm, Ce and La) micro/nanocrystals with abundant morphologies were synthesized via a one-step hydrothermal route without employing any surfactants. Furthermore, the homogeneous and well-defined KYb3F10 crystals with truncated tetragonal bipyramidal, nanoparticle, nanospherical, microtubular and rugby ball shapes were achieved by manipulating the different environments of crystal growth, such as increasing the concentration of Fâ, adjusting the pH, using different fluorine sources and adding trisodium citrate. XRD, SEM, EDS and PL as well as lifetime analysis were used to characterize the products. The obtained KYb3F10:Ln3+ products showed bright emission colors red (Eu3+) and green (Tb3+), respectively. It has been found that larger crystal shapes/sizes can greatly enhance their luminescence properties and lifetimes due to their high crystallinity and few defects on the crystal surface. The as-synthesized KYb3F10:Eu3+/Tb3+ products might be potentially applied in multicolor lighting and displays.