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... Efficiency droop at high carrier-injection regimes is a matter of concern in InGaN/GaN quantum-confined heterostructure-based light-emitting diodes (LEDs). Processes such as Shockley–Reed–Hall and Auger recombinations, electron–hole wavefunction separation from polarization charges, carrier leakage, and current crowding are identified as the primary contributors to efficiency droop. Auger recombin ...
... The band-edge carrier recombination rate determines the internal quantum efficiency of light-emitting diodes (LEDs), which is predominantly determined by the carrier lifetime. Point defects in transition metal dichalcogenides (TMDs) as dominant nonradiative recombinations affect the carrier lifetimes, hindering photon emission. Uncovering the mechanism of different defect types on carrier lifetime ...
... We report on the experimental observation of a Tamm plasmon state in the near-IR region characterized by an anomalously high energy level located in the upper half of the photonic band gap. Such a “blue” Tamm plasmon was demonstrated at the interface between a conventional, completely periodic Bragg reflector and a nanostructured nonresonant thin gold grating. We study the effect of the grating pe ...
photons, etc ; droplets; imbibition; nanopores; solvents; Show all 5 Subjects
Abstract:
... Hypothesis Self-assembly of colloidal particles enables the versatile fabrication of highly ordered structures and materials for optical, sensing, and other applications. Nevertheless, many traditional assembly processes are inefficient, because there exists an inevitable contradiction between time efficiency and crystalline quality. In this work, we introduce an ultrafast, robust, and scalable ap ...
... Perovskite solar cells (PSCs) are considered to be ideal energy devices, where perovskite-type organic metal halides act as light-absorbing materials. In PSCs, the photoexcitons are extracted and separated to afford high photoelectric conversion efficiency under the action of the built-in electric field (Ebᵢ). However, the current challenge is that a low Ebᵢ cannot provide a sufficient driving for ...
photons, etc ; absorption; cations; dyes; ligands; photocatalysis; Show all 6 Subjects
Abstract:
... Utilization of multiphotons to achieve high reduction potentials is a highly demanding but still challenging task for reductive cleavage of inert bonds. Herein, we report a new charge transfer approach that simultaneously excites the electron-rich dye and the radical anionic of the electron-deficient one for photocatalytic activation of aryl chlorides with high reduction potentials (Eᵣₑd ≈ −1.9 to ...
photons, etc ; crystallites; energy; photoluminescence; physical chemistry; Show all 5 Subjects
Abstract:
... Time-correlated single photon counting has been conducted to gain further insights into the short photoluminescence lifetimes (nanosecond) of lead iodide perovskite (MAPbI₃) thin films (∼100 nm). We analyze three different morphologies, compact layer, isolated island, and connected large grain films, from 14 to 300 K using a laser excitation power of 370 nJ/cm². Lifetime fittings from the Generali ...
photons, etc ; electric field; fluorescence; liquid crystals; Show all 4 Subjects
Abstract:
... Circularly polarized luminescence (CPL)-active materials with high dissymmetry factor (gₗᵤₘ) values show great potential in photonic devices. In this study, electric-field-driven systems with tunable CPL signals are successfully fabricated based on polymer-stabilized cholesteric liquid crystal (PSChLC) doping by fluorescent molecules. By constructing a gradient helical superstructure of PSChLCs, d ...
photons, etc ; hydrogels; hydrogen; milk; polymerization; porous media; Show all 6 Subjects
Abstract:
... In comparison with molecularly imprinted photonic hydrogel (MIPH) with specific molecular recognition sites inside matrix, surface molecularly imprinted photonic hydrogel (S-MIPH) is more competitive as a molecular sensor due to presence of molecular recognition sites distributed on surface of hydrogel wall. Nevertheless, the construction of S-MIPH sensors is still challenging owing to the absence ...
photons, etc ; ammonia; lipophilicity; methanol; ultraviolet-visible spectroscopy; Show all 5 Subjects
Abstract:
... 3,3′-ditetradecyloxacarbocyanine (DiOC₁₄(3)) and 3,3′-Dioctadecyloxacarbocyanine (DiOC₁₈(3)) are lipophilic carbocyanine dyes with a conjugated polymethine backbone and two long hydrocarbon tails. In this paper, we report the formation of Davydov-split aggregates of DiOC₁₄(3) and DiOC₁₈(3) in methanol/water mixtures with and without ammonia, which show a blue-shifted H-band and a red-shifted J-ban ...
photons, etc ; absorption; energy conversion; fluorescence; naphthalene; solar energy; Show all 6 Subjects
Abstract:
... Triplet–triplet annihilation photon upconversion (TTA-UC) is a process in which triplet excitons combine to form emissive singlets and holds great promise in biological applications and for improving the spectral match in solar energy conversion. While high TTA-UC quantum yields have been reported for, for example, red-to-green TTA-UC systems, there are only a few examples of visible-to-ultraviole ...
photons, etc ; cost effectiveness; liquid crystals; reflectance; silicon; transmittance; Show all 6 Subjects
Abstract:
... A photonic lattice is an efficient platform for optically exploring quantum phenomena. However, its fabrication requires high costs and complex procedures when conventional materials, such as silicon or metals, are used. Here, we demonstrate a simple and cost-effective fabrication method for a reconfigurable chiral photonic lattice of the helical nanofilament (HNF) liquid crystal (LC) phase and di ...
photons, etc ; bioimaging; drugs; energy; photocatalysis; photoluminescence; solar energy; Show all 7 Subjects
Abstract:
... Carbon quantum dots (CQDs), the intensifying nanostructured form of carbon material, have exhibited incredible impetus in several research fields such as bio-imaging, bio-sensing, drug delivery systems, optoelectronics, photovoltaics, and photocatalysis, thanks to their exceptional properties. The CQDs show extensive photonic and electronic properties, as well as their light-collecting, tunable ph ...
photons, etc ; hydrophilicity; luminescence; night vision; opal; solar radiation; Show all 6 Subjects
Abstract:
... Optical anticounterfeiting plays a vital role in information security because it can be recognized by the naked eye and is difficult to imitate. Herein, a hydrophilic modified upconversion nanoparticle (M-UCNP)-integrated bilayer inverse opal photonic crystal (IOPC) film was designed in which the luminescent M-UCNPs were deposited on the surface of the optimized bilayer structure with double photo ...
photons, etc ; computer software; heptane; hexane; magnetic fields; octane; pentane; Show all 7 Subjects
Abstract:
... In the present research work, we employed the transfer matrix method (TMM) in addition to MATLAB software to examine the transmission properties of various organic-based one-dimensional (1D) magnetic cold-plasma photonic crystals (MCPPhCs). The proposed structures were found to be made up of periodic layers of organic materials and magnetic cold-plasma (MCP) at normal incidence. An external magnet ...
Zachariah Hennighausen; Darshana Wickramaratne; Kathleen M. McCreary; Bethany M. Hudak; Todd Brintlinger; Hsun-Jen Chuang; Mehmet A. Noyan; Berend T. Jonker; Rhonda M. Stroud; Olaf M. van ’t Erve
photons, etc ; absorption; ambient temperature; desorption; disulfides; oxygen; photoluminescence; tungsten; Show all 8 Subjects
Abstract:
... Characterizing and manipulating the circular polarization of light is central to numerous emerging technologies, including spintronics and quantum computing. Separately, monolayer tungsten disulfide (WS₂) is a versatile material that has demonstrated promise in a variety of applications, including single photon emitters and valleytronics. Here, we demonstrate a method to tune the photoluminescence ...
photons, etc ; X-radiation; crystal structure; detection limit; photoluminescence; radiography; Show all 6 Subjects
Abstract:
... Recently, organic-inorganic hybrid scintillators have received more and more attention because of their merits of easy preparation, good stability, and nontoxicity. Considering the high cost of traditional inorganic scintillators, here we describe experimental investigations of a low-cost zero-dimensional scintillator comprising organic-inorganic hybrid cuprous halide and its capabilities for sens ...
photons, etc ; absorption; cellulose; color; light intensity; nanocrystals; polymers; solubility; Show all 8 Subjects
Abstract:
... Recent advances in structural-color cellulose nanocrystal (CNC) materials have been made toward chemical sensing applications; however, such materials lack sufficient color chroma for naked-eye observation, and their selective recognition to given chemicals as well as the corresponding mechanism has rarely been reported. Here, a dopamine-infiltration and post-polymerization approach is proposed to ...
photons, etc ; Cephalopoda; camouflage; chemistry; chromatophores; color; ligands; particle size; squid; Show all 9 Subjects
Abstract:
... The remarkable dynamic camouflage ability of cephalopods arises from precisely orchestrated structural changes within their chromatophores and iridophores photonic cells. This mesmerizing color display remains unmatched in synthetic coatings and is regulated by swelling/deswelling of reflectin protein nanoparticles, which alters platelet dimensions in iridophores to control photonic patterns accor ...
photons, etc ; biosensors; detection limit; enterotoxins; liquids; nanogold; oligonucleotides; opal; toxicity; Show all 9 Subjects
Abstract:
... Although there is considerable interest in self-assembly of ordered, porous “inverse opal” structures for optical, electronic, and chemical applications, uncontrolled defect formation limits the usefulness of such materials. Herein, we develop a highly ordered and plasmonic enhanced sensing inverse opal photonic crystal (IOPC) material. The co-assembly of the colloidal template with the matrix mat ...