Well-dispersed KRE 3 F 10 (RE = Sm–Lu, Y) nanocrystals: solvothermal synthesis and luminescence properties

A facile solvothermal route has been developed to synthesize a series of well-dispersed KRE3F10 (RE = Sm–Lu, Y) colloidal nanocrystals (NCs) with a rich variety of morphologies, such as hexagonal nanoplates, nanocubes and nanoparticles. X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and photoluminescence (PL) spectra were used to characterize the samples. It is found that the formation of monodisperse nanocrystals closely correlates with the nature of the rare earth series from La to Lu, Y. Based on the experimental results, the possible growth mechanisms for products with diverse architectures have been presented. The obtained NCs are highly crystalline and can be well dispersed in cyclohexane to form stable and clear colloids, which all display self-activated luminescence due to the trap states of surface defects.