We have analyzed the dynamics of upconversion-induced delayed fluorescence for a model multicomponent organic system, in which high concentrations triplet states can be sustained steady-state conditions. At different excitation powers, two regimes been identified depending on main deactivation channel triplets, namely, spontaneous decay and bimolecular annihilation. The power density at annihilation becomes dominant is threshold $({I}_{\text{th}})$ to efficient upconversion generation....

The self-assembly paradigm in chemistry, physics and biology has matured scientifically over the past two-decades to a point of sophistication that one can begin exploit its numerous attributes nanofabrication. In what follows we will take brief look at current thinking about with some recent examples taken from our own work examine how nanofabrication benefited self-assembly.

Semiconductor-metal hybrid nanostructures offer a highly controllable platform for light-induced charge separation, with direct relevance their implementation in photocatalysis. Advances the synthesis allow control over size, shape and morphology, providing tunability of optical electronic properties. A critical determining factor photocatalytic cycle is metal domain characteristics particular its subject that lacks deep understanding. Here, using well-defined model system cadmium...

Abstract One‐dimensional photonic structures, known as Bragg stacks or reflectors mirrors, represent a well‐developed subject in the field of optical science. However, because lack dynamic tunability and their dependence on complex top‐down techniques for fabrication, they have received little attention from materials science community. Herein, we present recent ongoing developments way to functional one‐dimensional structures obtained simple bottom‐up techniques. We focus versatility this...

The optical response of metallic nanostructures after intense excitation with femtosecond-laser pulses has recently attracted increasing attention: such is dominated by ultrafast electron–phonon coupling and offers the possibility to achieve modulation unprecedented terahertz bandwidth. In addition noble metal nanoparticles, efforts have been made in recent years synthesize heavily doped semiconductor nanocrystals so as a plasmonic behavior spectrally tunable features. this work, we studied...

Synthesis approaches to colloidal Cu3P nanocrystals (NCs) have been recently developed, and their optical absorption features in the near-infrared (NIR) interpreted as arising from a localized surface plasmon resonance (LSPR). Our pump–probe measurements on platelet-shaped Cu3-xP NCs corroborate plasmonic character of this absorption. In accordance with studies crystal structure analysis dating back 1970s, our density functional calculations indicate that material is substoichiometric...

Great control over size, shape and optical properties is now possible in colloidal Cd-based nanocrystals, which has paved the way for many fundamental studies applications. One popular example of such class nanocrystals represented by CdSe(spherical core)/CdS(rod shell) nanorods. These can be nearly monodisperse size have strong stable photoluminescence that tunable visible range (mainly varying CdSe core). The corresponding Zn-based core/shell nanorods would good candidates emission blue-UV...

We describe the colloidal hot-injection synthesis of phase-pure nanocrystals (NCs) a highly abundant mineral, chalcopyrite (CuFeS2). Absorption bands centered at around 480 and 950 nm, spanning almost entire visible near-infrared regions, encompass their optical extinction characteristics. These peaks are ascribable to electronic transitions from valence band (VB) empty intermediate (IB), located in fundamental gap mainly composed Fe 3d orbitals. Laser-irradiation (at 808 nm) an aqueous...

A π-extended double [7]carbohelicene 2 with fused pyrene units was synthesized, revealing considerable intra- and intermolecular π–π interactions as confirmed X-ray crystallography. As compared to the previous 1, homologue demonstrated considerably red-shifted absorption an onset at 645 nm (1: 550 nm) corresponding a smaller optical gap of 1.90 eV 2.25 eV). broad near-infrared emission from 600 900 large Stokes shift ∼100 (2.3 × 103 cm–1) recorded for 2, implying formation intramolecular...

Hybrid semiconductor–metal nanoparticles are interesting materials for use as photocatalysts due to their tunable properties and chemical processibility. Their function in the evolution of hydrogen photocatalytic water splitting is subject intense current investigation. Here, effects surface coatings on studied, with Au-tipped CdS nanorods a model hybrid nanoparticle system. Kinetic measurements rate following reduction performed similar but different coatings, including various types...

The 2D semiconductor MoS 2 in its mono‐ and few‐layer form is expected to have a significant exciton binding energy of several 100 meV, suggesting excitons as the primary photoexcited species. Nevertheless, even single layers show strong photovoltaic effect work active material high sensitivity photodetectors, thus indicating efficient charge carrier photogeneration. Here, modulation spectroscopy sub‐ps ms time scales used study photoexcitation dynamics . results suggest that...

Abstract A large number of graphene molecules, or polycyclic aromatic hydrocarbons (PAHs), have been synthesized and display various optoelectronic properties. Nevertheless, their potential for application in photonics has remained largely unexplored. Herein, we describe the synthesis a highly luminescent stable molecule, namely substituted dibenzo[ hi , st ]ovalene (DBO 1 ), with zigzag edges elucidate its promising optical‐gain properties by means ultrafast transient absorption...

The nanoscale modulation of material properties such as porosity and morphology is used in the natural world to mold flow light obtain structural colors. ability mimic these strategies while adding technological functionality has potential open up a broad array applications. Porous photonic crystals are one candidate, but have typically underachieved terms available materials, optical quality, compatibility with different substrates (e.g., silicon, flexible organics), scalability. We report...

We report on the laser action in a microcavity where both dielectric mirrors and active material have macromolecular nature, resulting full plastic device. Distributed Bragg reflectors (DBRs) are prepared by spin-coating of polyvinylcarbazole cellulose acetate orthogonal solutions layer consists highly fluorescent conjugated polymer poly(9,9-dioctylfluorenyl-2,7-diyl-co-1,4-benzo-(2,1'-3)-thiadiazole) (F8BT) spun film. A quality factor range 80–180 is achieved cavity mode carefully tuned...

Photonic crystal-based biosensors hold great promise as low-cost devices for real-time monitoring of a variety biotargets, example, bacterial contaminants in food. Here, we report the proof-of-concept new colorimetric sensor contamination, which is based on novel hybrid plasmonic–photonic device. Our system consists layer silver, plasmonic metal exhibiting well-known bioactivity, top one-dimensional photonic crystal. We attribute bioresponsivity to formation polarization charges at...

Abstract Here we report a comprehensive analysis of the robustness seven high-quality real-world complex weighted networks to errors and attacks toward nodes links. We use measures network damage conceived for binary (e.g. largest connected cluster LCC , efficiency Eff bin ) or structure total flow TF ). find that removing very small fraction links with respectively higher strength weight triggers an abrupt collapse functioning while evaluate binary-topological connectedness are almost...

In this report we offer the widest comparison of links removal (attack) strategies efficacy in impairing robustness six real-world complex weighted networks. We test eleven different link by computing their impact on network means using three measures, i.e. largest connected cluster (LCC), efficiency (Eff) and total flow (TF). find that, most cases, strategy based binary betweenness centrality is efficient to disrupt LCC. The binary-topological features are less decreasing measures (e.g. Eff...

Abstract Two‐dimensional transition metal dichalcogenides (2D TMDCs) have gained significant attention from the scientific community due to their exceptional properties. Recently, metal‐assisted exfoliation technique has emerged as a promising method for producing large‐area, high‐quality 2D monolayers. However, achieving strong adhesion between foil and substrate during process remains major challenge, preventing successful exfoliation. To overcome this issue, study explores application of...

Nanoparticle one-dimensional photonic crystals (see image) possess high reflectivity arising from Bragg diffraction of light incident on a lattice comprising nanoparticle layers alternating refractive index. The provide mesoporosity, allowing for the introduction variety functional molecules and materials into intrananoparticle voids, creating myriad opportunities development new kinds optical optoelectronic devices.

This paper describes the use of chemical cross-linking ultrathin inorganic nanowires as a bottom-up strategy for nanostructure fabrication well detection platform. Nanowire microfibers are produced by spinning nanowire dispersion into cross-linker solution at room temperature. Nanomembranes with thicknesses down to 50 nm were obtained injecting cross-linker-solution/air interface. Furthermore, sensitivity amine cross-linkers allowed development novel sensing platform small molecules, like...