Impact of Lanthanide Nanomaterials on Photonic Devices and Smart Applications

A novel one-pot strategy to rapidly synthesize bright red emitting upconversion nanocrystals with core–shell–shell structure

By growing NaYbF₄ and NaYF₄ on β-NaErF4:0.005Tm in one pot, the upconversion intensity was tremendously enhanced.

UV-Vis-NIR absorption spectra of lanthanide oxides and fluorides

Absorption spectra of inorganic lanthanide fluorides and oxides.

Luminescence properties of pyrazolic 1,3-diketone Ho3+ complex with 1,10-phenanthroline

We performed spectroscopic investigations of a novel tris(1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)propane-1,3-dionato)(1,10-phenanthroline) holmium (III) complex. It was demonstrated that bonding the corresponding ligand environment to Ho³⁺ results in sensitization of the luminescence of the complex. The luminescence decay of the complex exhibits a biexponential behaviour. The short-lived component is attributed to the fluorescence of the ligand, whereas the long-lived component is connected with the Ho³⁺ emission. Using fluorescence lifetime imaging, it was shown that there is a single type of emission sites in the studied complex. Based on the results of the optical measurements, the energy diagram for the investigated Ho³⁺ complex was developed. It was shown that the energy transfer from the excited triplet level of the ligand environment to the ⁵F₅ level of Ho³⁺ is responsible for the emission of the ion in the complex.

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

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.

Recent development of electro-responsive smart electrorheological fluids

The characteristics of an electrorheological (ER) fluid, as a class of smart soft matter, can be actively and accurately tuned between a liquid- and a solid-like phase by the application of an electric field. ER materials used in ER fluids are electrically polarizable particles, which are attracting considerable attention in addition to further research. This perspective reports the latest ER materials along with their rheological understanding and provides a forward-looking summary of the potential future applications of ER technology.

Upconversion Nanocomposite Materials With Designed Thermal Response for Optoelectronic Devices

Upconversion is a non-linear optical phenomenon by which low energy photons stimulate the emission of higher energy ones. Applications of upconversion materials are wide and cover diverse areas such as bio-imaging, solar cells, optical thermometry, displays, and anti-counterfeiting technologies, among others. When these materials are synthesized in the form of nanoparticles, the effect of temperature on the optical emissions depends critically on their size, creating new opportunities for innovation. However, it remains a challenge to achieve upconversion materials that can be easily processed for their direct application or for the manufacture of optoelectronic devices. In this work, we developed nanocomposite materials based on upconversion nanoparticles (UCNPs) dispersed in a polymer matrix of either polylactic acid or poly(methyl methacrylate). These materials can be processed from solution to form thin film multilayers, which can be patterned by applying soft-lithography techniques to produce the desired features in the micro-scale, and luminescent tracks when used as nanocomposite inks. The high homogeneity of the films, the uniform distribution of the UCNPs and the easygoing deposition process are the distinctive features of such an approach. Furthermore, the size-dependent thermal properties of UCNPs can be exploited by a proper formulation of the nanocomposites in order to develop materials with high thermal sensitivity and a thermochromic response. Here, we thus present different strategies for designing optical devices through patterning techniques, ink dispensing and multilayer stacking. By applying upconverting nanocomposites with unique thermal responses, local heating effects in designed nanostructures were observed.

Degradable magnetic-response photoacoustic/up-conversion luminescence imaging-guided photodynamic/photothermal antitumor therapy

In this research, a degradable uniform mesoporous platform was designed as an imaging-guided photothermal therapy (PTT)/photodynamic therapy (PDT) agent.

Hemocompatibility investigation and improvement of near-infrared persistent luminescent nanoparticle ZnGa2O4:Cr3+ by surface PEGylation

ZnGa₂O₄:Cr³⁺ hemocompatibility was systematically investigated from the aspects of hemolysis, erythrocyte morphology, coagulation and complement system activation, and greatly improved by surface PEGylation.

Visible light sensitized near-infrared luminescence of ytterbium via ILCT states in quadruple-stranded helicates

Quadruple-stranded helicates show visible light sensitized near-infrared luminescence of ytterbium via ILCT states.

Synthesis, structure, photoluminescent, optical and magnetic properties of a novel thulium p-hydroxybenzenesulfonate complex

A novel thulium p-hydroxybenzenesulfonate complex [Tm(C6H5O4S)2(H2O)6](C6H5O4S)·3H2O (1) was solvothermally synthesized and characterized by elemental analyses, photoluminescence, solid-state UV/vis diffuse reflectance, magnetic measurements and single-crystal X-ray diffraction. Complex 1 features an ionic structure with the thulium ion possessing a square antiprismatic geometry. Complex 1 crystallized in the monoclinic system with space group P21. Photoluminescent measurements with solid-state sample demonstrate that the anti-Stokes emission bands in the red/NIR spectral region 710 and 812 nm are observed from the Tm3+ 4f intrashell transitions from the 3F2,3 excited states to the 3H6 and 1G4 excited state to the 3H5 state, respectively. Solid-state UV/vis diffuse reflectance spectra of complex 1 show the existence of a wide optical band gap of 3.56 eV. Variable-temperature magnetic susceptibility and field dependence magnetization measurements are also studied and the magnetic susceptibility obeys the Curie-Weiss law (χ m =c/(T−θ)) with the value C being of 8.6 K and a negative Weiss constant θ being of −0.2 K.

Synthesis and phase transformation of NaGdF4:Yb–Er thin films using electro-deposition method at moderate temperatures

Herein, a thin film of hexagonal-phase NaGdF₄:Yb–Er is fabricated by electro-deposition at moderate temperatures. The phase of NaGdF₄:Yb–Er thin film can be controlled by adding PVP in the electrolyte.