Spectral and spatial characterization of upconversion luminescent nanocrystals as nanowaveguides

Construction of highly efficient carbon dots-based polymer photonic luminescent solar concentrators with sandwich structure

The enhancement of photoluminescence (PL) emission and waveguide play a key role in improving the optical efficiency of luminescent solar concentrators (LSCs). In this work, to boosting PL emission and waveguide simultaneously, one photonic crystal (PC) structure (crystalline colloid arrays (CCAs)) was introduced into carbon dots (CDs)-based polymer LSCs. A sandwich-structured CDs-based polymer photonic LSC, comprising glass/CDs-based polymer PC film/glass, was created. First, CDs-based colloidal crystal suspensions were prepared by co-assembly of monodispersed p(MMA-NIPAm) colloids and multicolor-emitting CDs in HEMA monomer induced by the evaporation-driven assembly. The obtained suspensions not only had uniform PL and structural colors, but showed enhanced PL emission. Second, the above suspensions were sandwiched between two glass sheets and finally a photonic polymer LSC with sandwiched structure (25 × 25 × 1.8 mm³) were formed via one-step photopolymerization technique. Remarkably, the optimal CDs-based polymer photonic LSCs with sandwiched structure not only had high transparence at visible range (>60%), but exhibited PL emission enhancement (at least 2 times). Furthermore, the maximum external optical efficiency (η_opt) of 5.84% could be achieved based on yellow-emitting CDs-based polymer photonic LSC. The high external optical efficiency was mainly attributed to the PL emission enhancement and good PC waveguide.

Schiff Base Tetranuclear Zn2Ln2 Single-Molecule Magnets bridged by Hydroxamic acid in association with Near-Infrared Luminescence

A series of Zn-Ln heteronuclear SMMs formed by hexadentate compartment Schiff base Zn-precursor and lanthanoid ions were structurally and magnetically characterized, in which the two [Zn-Ln] moieties are bridged by...

Organic Polymer Hosts for Triplet-Triplet Annihilation Upconversion Systems

Triplet-triplet annihilation upconversion (TTA-UC) is a process by which a lower energy photon can be upconverted to a higher energy state. The incorporation of TTA-UC materials into solid-state hosts has enabled advances in solar energy and many other applications. The choice of host system is, however, far from trivial and often calls for a careful compromise between characteristics such as high molecular mobility, low oxygen diffusion, and high material stability, factors that often contradict one another. Here, we evaluate these challenges in the context of the state-of-the-art of primarily polymer hosts and the advantages they hold in terms of material selection and tunability of their diffusion or mechanical or thermal properties. We encourage more collaborative research between polymer scientists and photophysicists in order to further optimize the current systems and outline our thoughts for the future direction of the field.

Switchable up-conversion luminescence bioimaging and targeted photothermal ablation in one core–shell-structured nanohybrid by alternating near-infrared light

Upon NIR irradiation, a GdOF:Yb/Er@(GNRs@BSA)-FA nanohybrid was expected to be a potential multifunctional imaging tracer and photothermal ablation agent switched controllably for cancer theranostics.

Interconversion between KSc2F7:Yb/Er and K2NaScF6:Yb/Er nanocrystals: the role of chemistry

Interconversion between nanocrystals of orthorhombic KSc₂F₇:Yb/Er and cubic K₂NaScF₆:Yb/Er was realized by adjusting the according chemical reaction conditions.