Anisotropic Excitation Polarization Response from a Single White Light‐Emitting β‐NaYF₄:Yb³⁺,Pr³⁺ Microcrystal

Abstract

Precise knowledge about optical and structural performance of individual rare earth (RE)‐doped particles is extremely important for the optimization of luminescent particles and for fully exploiting their capability as multifunctional probes for interdisciplinary applications. In this work, optical and structural anisotropy of individual particles through RE‐doped single fluoride microcrystals with controllable morphology is reported. Unique luminescent phenomena, for example, white light‐emission from Pr3+ at single particle level and different photoluminescent spectra variation dependence on excitation polarization orientation at different excitation direction are observed upon excitation with a 980 nm linearly polarized laser. Based on the analysis of local site symmetry and electron cloud distribution of REs in hexagonal structure by density functional theory calculations, an exciting mechanism of excitation polarization response anisotropy is given for the first time, providing a guidance for emission polarization simultaneously. The structural anisotropy is presented in Raman spectra with obvious differing Raman curves, revealing the reason why there are differences between powder groups. Taking advantage of anisotropic crystals, potential applications in microscopic multi‐information transportation are suggested for the optical and structural performance anisotropy from RE‐doped fluoride single nano/microcrystals to ordered nano/microcrystal arrays, such as local rate probing in a flowing liquid.

Color regulation for Eu(tta)3phen/E7 composites by interaction between Eu(iii) complexes and liquid crystals

“…In recent decades, rare earth (RE) ion doped materials have been applied in many fields such as light emitting diode (LED) phosphors, biological imaging and temperature sensing owing to their excellent light-emitting properties. 1–5 The unique luminescence properties range over long luminescence lifetimes and high color purity can be attributed to the 4f–4f transitions in RE ions. 6 Nevertheless, the emission color of each lanthanide ion is usually fixed based on its own energy levels, which will adversely affect the application of luminescence materials.…”

Measuring 3D orientation of nanocrystals via polarized luminescence of rare-earth dopants

“…In this study, as a proof of concept of this method, we investigated the 3D orientation of monocrystalline sodium yttrium fluoride (NaYF 4 ) nanorods doped with trivalent europium (Eu 3+ ) ions. NaYF 4 is an efficient crystalline matrix for lanthanide doping and is widely studied for applications in upconversion probes 49 – 52 and nanothermometry 53 , 54 . As compared to other common emitting ions, Eu 3+ ion shows sharp and well-defined emission peaks, thanks to the non-degenerate upper level of its main emission ( 5 D 0 → 7 F J ), which is ideal for the spectroscopic orientation analysis.…”

Cholesteric‐Superhelix‐Enabled Reconfigurable Circularly Polarized Luminescence from Uniaxially Aligned Upconversion Nanorod Films

“…[22][23][24] As known, the luminescence of UCNPs with anisotropic crystalline symmetries shows a distinct polarization anisotropy. [25][26][27] Polarized upconversion luminescence (UCL) enables UCNPs great potentials in emergent optical and biological applications. A linearly polarized UCL can be generated via uniaxially aligned upconversion nanorods (UCNRs).…”