Nanomaterials (Basel)
September 2020
The nanoresolution of geometric phase elements for visible wavelengths calls for a flexible technology with high throughout and free from vacuum. In this article, we propose a high-efficiency and simple manufacturing method for the fabrication of geometric phase elements with femtosecond-laser direct writing (FsLDW) and thermal annealing by combining the advantages of high-efficiency processing and thermal smoothing effect. By using a femtosecond laser at a wavelength of 343 nm and a circular polarization, free-form nanogratings with a period of 300 nm and 170-nm-wide grooves were obtained in 50 s by laser direct ablation at a speed of 5 mm/s in a non-vacuum environment.
View Article and Find Full Text PDFBackground: Laparoscopic splenectomy (LS) is regarded as a second-line treatment for medically refractory idiopathic thrombocytopenic purpura (ITP), but the predictive factors for the long-term postoperative responses to ITP are still a matter of debate. We aimed to investigate the factors that can predict the long-term response after LS for Chinese patients with medically refractory ITP.
Methods: From January 2011 to September 2016, 78 Chinese patients with ITP who underwent LS were retrospectively analyzed.
Silicon photonics integrated circuits (Si-PIC) with well-established active and passive building elements are progressing towards large-scale commercialization in optical communications and high speed optical interconnects applications. However, current Si-PICs do not have memory capabilities, in particular, the non-volatile memory functionality for energy efficient data storage. Here, we propose an electrically programmable, multi-level non-volatile photonics memory cell (PMC) fabricated by standard complementary-metal-oxide-semiconductor (CMOS) compatible processes.
View Article and Find Full Text PDFThe photo-reduction of metal ions in solution induced by femtosecond laser is an important and novel method for fabricating three-dimensional metal microstructures. However, the nonlinear absorption cross section of metal ions remains unknown because its measurement is difficult. In the present study, a method based on Two-Photon Excited Sedimentation (TPES) is proposed to measure the two-photon absorption cross section (TPACS) of metal ions in solution.
View Article and Find Full Text PDFIn this work, the adsorption of human serum albumin (HSA) on the bare multiwall carbon nanotube (MWNT) was investigated by a new electrochemical method, termed as zero current potentiometry. For this, a MWNT strip was prepared by directly adhering MWNTs on the transparent adhesive tape surface. Moreover, when HSA adsorbed onto MWNT at the MWNT/solution interface, an interface potential Ψ yielded.
View Article and Find Full Text PDFIn this paper, we demonstrate a compact electrically pumped distributed-feedback hybrid III-V/silicon laser with laterally coupled Bragg grating for the first time to the best of our knowledge. The hybrid laser structure consists of AlGaInAs/InP multi-quantum-well gain layers on top of a laterally corrugated silicon waveguide patterned on a silicon on insulator (SOI) substrate. A pair of surface couplers is integrated at the two ends of the silicon waveguide for the optical coupling and characterization of the ouput light.
View Article and Find Full Text PDFWe present a design for spectral engineering in a metal dual distributed Bragg reflector (DBR)-based structure. Optical Tamm states and Fabry-Perot cavity mode, dual windows for light-matter interaction enhancement, can be excited simultaneously and tuned flexibly, including their respective bandwidth and resonant wavelength, due to the variable reflection phase from the outer DBR's internal surface. The design can find applications in solar cells for light trappings.
View Article and Find Full Text PDFAn ultra-smooth Ag film with sub-nanometer surface roughness on a flexible substrate has been fabricated by a template-stripping process and its effect on the carrier injection and transport in organic light-emitting devices (OLEDs) has been investigated. The use of the ultra-smooth Ag film as an electrode results in both enhanced carried injection due to the improved contact between the electrode and the organic layer and enhanced carrier transport due to the larger grain size of the deposited organic layer on it. The ultra-smooth Ag film on the flexible substrate has been applied in inverted top-emitting OLEDs (ITOLEDs) as cathode, which exhibit improved efficiency due to the enhanced electron injection and transport.
View Article and Find Full Text PDFWe report the fabrication of three-dimensional periodic metal nickel nanostructures achieved by the combination of femtosecond laser-induced two-photon polymerization and electroless plating technology. We can control the deposition speed of 10 nm per second by adjusting the reaction time. The thermal stability is good under 500 °C for the three-dimensional graphite-lattice polymer structure with 200 nm nickel film.
View Article and Find Full Text PDFWe demonstrate optimized viewing-angle characteristics from top-emitting organic light-emitting devices by integrating a periodic microstructure into the cavity. A holographic lithography technique combined with filling process of the groove by spin coating of a polymer film has been employed to enable its periodically and gradually changed cavity length and suppress the viewing-angle dependence of the peak emission wavelength and intensity. The theoretical and experimental results support that the proposed microstructured cavity can resolve the angular-dependence effect in a very simple and effective way, and a desired omnidirectional emission has been obtained.
View Article and Find Full Text PDFWe present novel nanoporous TiO(2)/polyion thin-film-coated long-period fiber grating (LPFG) sensors for the direct measurement of low-molecular-weight chemicals by monitoring the resonance wavelength shift. The hybrid overlay films are prepared by a simple layer-by-layer deposition approach, which is mainly based on the electrostatic interaction of TiO(2) nanoparticles and polyions. By the alternate immersion of LPFG into dispersions of TiO(2) nanoparticles and polyions, respectively, the so-formed TiO(2)/polyion thin film exhibits a unique nanoporous internal structure and has a relative higher refractive index than LPFG cladding.
View Article and Find Full Text PDFWe report grating amplitude dependence of electroluminescence (EL) in organic light-emitting devices with one-dimensional corrugated structure. Our proposed devices can emit light from both the top silver and bottom quartz side, and both exhibit amplitude-dependence EL enhancement. The effect of grating amplitude on the EL intensity has been studied experimentally and numerically to find out the optimal grating amplitude for the greatest EL enhancement.
View Article and Find Full Text PDFThe cathodic electrochemiluminescence (ECL) of peroxydisulphate (S(2)O(8)(2-))-ciprofloxacin (CPF) system at a wax-impregnated graphite electrode was studied. When CPF was absent, S(2)O(8)(2-) was electrochemically reduced to sulphate free radical (SO(4)(•-)), and dissolved oxygen absorbed on the electrode surface was reduced to protonated superoxide anion radical (HO(2)(•)). The HO(2)(•) was oxidized by SO(4)(•-) to produce molecular oxygen in both singlet and triplet states.
View Article and Find Full Text PDFSince the electrochemical oxidation peaks of both DNA and anti-tumor drug tamoxifen (TAM) overlapped with each other, the known electrochemical methods were limited in the study of the interactions between DNA and TAM. In this paper, zero current potentiometry, a new electrochemical method, was used to study the interaction of calf thymus dsDNA with TAM. The dsDNA was immobilized on the surface of carbon paste (dsDNA/CP).
View Article and Find Full Text PDFExciton quenching dynamics has been systematically studied in pristine P3HT and nano phase separated P3HT/PCBM blend films under various excitation intensities by femtosecond fluorescence up-conversion technique. The behaviors of excitons in the films can be well described by a three-dimensional diffusion model. The small diffusion length and large charge transfer radius indicate that excitons reach the interface most likely by the delocalization of the excitons in P3HT fibrillar at a range of 4.
View Article and Find Full Text PDFNovel multifunctional magnetic-mesoporous Janus particles with controlled aspect ratio were developed by a simple one-step synthesis approach. Due to their superior magnetic properties and well-defined pore structures, these particles will be important in drug delivery, molecule targeting, cellular imaging, and as building blocks for the assembly of complex nanostructures.
View Article and Find Full Text PDFBinary naoparticles composed of a superparamagnetic Fe(3)O(4) core and an Au nanoshell were prepared via a high-temperature hydrolysis reaction followed by seed-mediated growth. The nanoprobes render simultaneous dual functions of both fast magnetic response and local surface plasmon resonance. Using these nanoprobes, analyte molecules can be easily biologically captured, magnetically concentrated, and analyzed by surface-enhanced Raman scattering (SERS).
View Article and Find Full Text PDFIn this paper, an efficient and novel optical fiber-to-waveguide mode size converter for Si Photonics devices with sub-micron waveguides is developed on the SOI platform. This optical converter is composed of a suspended SiO(2) waveguide and overlapped Si nano-tapers located in the center of suspended SiO(2) waveguide. Laterally connected SiO(2) beams provide structural support for the suspended SiO(2) waveguide.
View Article and Find Full Text PDFA high performance monolithically integrated WDM receiver is fabricated on the SOI platform, with key components comprising a 1 x 32 Si-based AWG and an array of high speed waveguided Ge-on-Si photodetectors. The optical channel spacing is 200 GHz. This configuration was used to demonstrate 32-channel operation in the L-band, where it is particularly challenging for silicon photonics due to the low absorption coefficient of Ge at L-band wavelengths.
View Article and Find Full Text PDFA strong electrochemiluminescence (ECL) of palmatine in NaOH medium was observed at a vaseline-impregnated graphite anode. The ECL production could be described as follows: hydroxyl radical (OH(•)) was generated via the oxidation of hydroxyl group (OH(-)) in NaOH medium, and the formed OH(•) subsequently oxidized palmatine base converted from palmatine in NaOH medium to the excited state oxypalmatine (oxypalmatine*). As the oxypalmatine* went back to its ground state, a stronger chemiluminescence was produced.
View Article and Find Full Text PDFA simple yet sensitive method is developed for the determination of sericin using voltammetry based on the interaction between sericin and carmine for the first time. In the absence of sericin, carmine has a pair of well-defined redox peaks in a pH 1.81 Britton-Robinson buffer solution.
View Article and Find Full Text PDFA modified electrode Ni(II)-BA-MWCNT-PE has been fabricated by electrodepositing nickel(II)-baicalein [Ni(II)-BA] complex on the surface of multi-wall carbon nanotube paste electrode (MWCNT-PE) in alkaline solution. The Ni(II)-BA-MWCNT-PE exhibits the characteristic of improved reversibility and enhanced current responses of the Ni(III)/Ni(II) couple compared with Ni(II)-BA-CPE. It also shows good electrocatalytic activity toward the oxidation of hydrazine.
View Article and Find Full Text PDFA modified electrode, nickel(II)-baicalein complex modified multiwall carbon nanotube paste electrode (Ni(II)-BA-MWCNT-PE), has been fabricated by electrodepositing Ni(II)-BA complex on the surface of MWCNT-PE in alkaline solution. The Ni(II)-BA-MWCNT-PE exhibits the characteristic of improved reversibility and enhanced current responses of the Ni(III)/Ni(II) couple compared with Ni(II)-BA-carbon paste electrode (CPE). It also shows better electrocatalytic activity toward the oxidation of glycine than Ni(II)-MWCNT-PE.
View Article and Find Full Text PDFA new flow-injection chemiluminescence (CL) method for determination of chloroquine is proposed based on a stronger chemiluminescence of chloroquine in hydrogen peroxide-nitrite-sulfuric acid medium. The proposed method allows the measurement of chloroquine over the range of 3.0x10(-7) to 1.
View Article and Find Full Text PDFMicronanostructures prepared by two-photon photopolymerization are utilized as templates for electroless plating of metals, giving rise to an approach for fabricating complex-shaped metal micronanostructures that are so far not achievable by other means. We show that when the coated-layer thickness of a metal coating is larger than a critical value (around 20 nm for silver at 2-3 microm wavelength) associated with the metal's skin depth, the photonic crystals exhibit optical properties more comparable to a solid metal structure than to their polymer counterparts.
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