Well-dispersed KRE₃F₁₀(RE = Sm–Lu, Y) nanocrystals: solvothermal synthesis and luminescence properties

Abstract

A facile solvothermal route has been developed to synthesize a series of well-dispersed KRE 3 F 10 (RE ¼ 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.

KF-mediated controlled-synthesis of potassium ytterbium fluorides (doped with Er3+) with phase-dependent upconversion luminescence

“…1a). The crystal structure of cubic phase is determined with lattice parameters of a = b = c = 11.431 Å, space group of Fm m. 27 Upon a further increase of KF/Yb 3+ molar ratios, from 5 to 12.5, the well-defined diffraction peaks can be assigned readily to the orthorhombic phase of KYb 2 F 7 (JCPDS No. as-synthesized crystals, which could be related to the different characteristic unit cell structures for different crystallographic phases.…”

Hydrothermal Synthesis of Novel K2YbF5:Er3+/Y3+ Microcrystals with Tunable Red–Green Upconversion Luminescence

“…Thus efficient UC emission spanning from a wide region make them ideal for tunable UC lasers and scintillators [31,37]. Up to now, a number of researches about the synthesis, optical properties, and applications of these fluorides have been reported [33,35,37]. However, few studies are focused on the synthesis and UC luminescence properties of K 2 YbF 5 :Ln 3?…”

“…As a class of excellent efficient host materials for UC luminescence, potassium ytterbium (yttrium) fluorides, including KYb(Y)F 4 , KYb(Y) 3 F 10 , and KYb(Y) 2 F 7 has been extensively investigated [32,[34][35][36][37]. Compared with NaYF 4 host lattice, RE ions doped potassium ytterbium (yttrium) fluorides not only exhibit high UC luminescence efficiency in the visible region, but also emit additional lights in the ultraviolet and near-infrared regions.…”

Polymorph (C2N2H10)0.5RE3F10·xH2O (RE=Ho-Lu, Y) and REF3 nanocrystals: Hydrothermal synthesis, characterization and luminescence

“…Rare earth ions activated metal fluorides are thus favorable for the special luminescent behavior, such as the up-conversion from near infrared to visible light [10]. Despite being welldeveloped in the field of solid-state reaction method requiring high temperature and gas protection, hydrothermal technology has been proved to be a facile and efficient approach for the growth of metal fluorides [11][12][13]. Particularly it is still rarely reported to exploit organic moieties as templates or structure-directing agents in the preparation of metal fluorides.…”