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Electrogenerated Chemiluminescence and Spectroelectrochemistry Characteristics of Blue Photoluminescence Perovskite Quantum Dots
摘要： Lead-based perovskite MAPbX3 (MA= CH3NH3, X=Cl and Br) has shown great potential benefits to advance modern optoelectronics and clean energy harvesting devices. Poor structural stability is one of the major challenges of MAPbX3 perovskite materials to overcome to achieve desired device performance. Here we present the electrochemical stability study of CH3NH3PbCl1.08Br1.92 quantum dots (QDs) by electrogenerated chemiluminescence (ECL) and photoluminescence (PL) spectroelectrochemistry methods. Electrochemical anodization of pristine MAPbX3 QD film results in the disproportionate loss of methylammonium and halide ions (X=Cl and Br). ECL efficiency and stability of perovskite QDs in the presence of co-reactant tripropyl amine (TPrA) can be greatly improved after being incorporated into a polystyrene (PS) matrix. Mass spectrum and X-ray photoelectron spectroscopy (XPS) measurements are used to provide chemical composition variation details of QDs, responsible for the ECL and PL characteristics (e.g., wavelength redshift) of perovskite QDs in an electrochemical cell.
关键词： quantum dots (QDs),Perovskite,Blue light emission,nanocrystals,polystyrene (PS),electrogenerated chemiluminescence (ECL),photoluminescence (PL)
更新于2025-09-23 15:21:01
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Photo-induced meta-stable polar conformations in polystyrene microspheres revealed by time-resolved SHG microscopy
摘要： Photo-induced second harmonic generation (SHG) was observed in centrosymmetric polystyrene (PS) microspheres using 1064 nm, sub-nanosecond laser-pulse irradiation. The SHG signal gradually increased upon stationary laser-pulse irradiation. After stopping the irradiation, the increased SHG signal disappeared in approximately 30 min. When the PS bead was irradiated by laser pulses again, the SHG signal reappeared with similar temporal behavior, which was attributed to the probable growth and contraction of meta-stable polar conformations of PS chain segments under periodic photo-thermal stimuli.
关键词： second harmonic generation,photo-induced,polystyrene microspheres,time-resolved SHG microscopy
更新于2025-09-23 15:19:57
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High indoor performance of flexible organic photovoltaics using polymer electrodes
摘要： Indoor organic photovoltaics (OPVs) have gained tremendous attention due to their unique optoelectronic properties under dim and spectrally-limited indoor light conditions. Moreover, their excellent flexible features make them more suitable for powering various indoor electronic devices than other photovoltaic systems. In this article, we demonstrate the indoor photovoltaic performance of poly(3-hexylthiophene):indene-C60 bisadduct-based flexible OPVs with polymeric electrodes in comparison with reference OPVs with indium tin oxide (ITO) electrodes. For the flexible OPVs, poly (3, 4-ethylenedioxythiophene): poly (styrene-sulfonic acid)-based polymeric electrodes were demonstrated on a polyethylene naphthalate substrate with a polyvinyl alcohol buffer layer. The OPV with the polymeric electrode produced an average power conversion efficiency (PCE) of 11.1 ± 0.1%, whereas the reference device with the ITO electrode exhibited a PCE of 8.8 ± 0.1% under a 500-lx-light emitting diode condition. The flexible OPVs also exhibited superior flexibility over reference OPVs by retaining their PCE up to ~ 85% even after 500 bending cycles in air, whereas the reference OPVs declined to ~ 80% of their PCE under the same bending conditions.
关键词： Organic photovoltaics,Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate,Polymeric electrode,Indoor application,Parasitic resistance effects
更新于2025-09-23 15:19:57
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Enhanced Optical Output of Near-Ultraviolet Light-Emitting Diodes by a Monolayer of Nanospheres
摘要： The optical output of near-ultraviolet (NUV) light-emitting diodes (LEDs) was improved by including a monolayer of hexagonal close-packed polystyrene (PS) nanospheres. PS nanospheres with different sizes were deposited on the indium tin oxide layer of the NUV LEDs. The electroluminescence results showed that the light extraction efficiency of the NUV LEDs was increased by the inclusion of PS nanospheres, and the maximum optical output enhancement was obtained when the size of the nanospheres was close to the light wavelength. The largest enhancement of the optical output of 1.27-fold was obtained at an injection current of 100 mA. The enhanced optical output was attributed to part of the incident light beyond the critical angle being extracted when the exit surface of the NUV LEDs had a PS nanosphere monolayer. This method may serve as a low-cost and effective approach to raise the efficiency of NUV LEDs.
关键词： polystyrene nanospheres,optical output enhancement,near-ultraviolet,light-emitting diodes,light extraction efficiency
更新于2025-09-23 15:19:57
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Nanostructuring of honeycomb-like polystyrene with excimer laser
摘要： This paper is aimed on the construction of honeycomb like patterns (HCP) with defined dimensions of pores on activated solid-state substrate. Dip coating technique with improved phase separation was used for pattern preparation, subsequent nanostructuring was realized with an excimer laser. Polystyrene patterns were prepared on perfluorethylenepropylene, which were subsequently treated with laser wavelength 248 nm. The main goal was to prepare honeycomb like pattern and by interaction of such microstructure with an excimer laser to prepare superposed structure. This idea was fully fulfilled, uniform micropattern on perfluorinated polymer was prepared, with several laser fluences and number of pulses to be tested subsequently. Optimal conditions of KrF exposure were determined to be 6000 pulses and interval of laser treatment from 8 to 16 mJ.cm?2, by this combination of input parameters a superposed globular nanostructure was constructed on honeycomb-like polystyrene microstructure. Surface wettability, morphology and chemistry of nanopatterned microstructures were changed significantly, oxygen concentration of treated substrates was significantly increased. Particular stages of globular pattern formation were studied and described in detail by atomic force microscopy, scanning electron microscopy, EDS/EDX and XPS analysis. Elemental mapping was applied for detailed analysis of prepared superposed pattern.
关键词： Excimer laser,Perfluorethylenepropylene,Polymer,Polystyrene,Honeycomb pattern,Nanostructure
更新于2025-09-23 15:19:57
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Reduced graphene oxide@ceria nanocomposite-coated polymer microspheres as a highly active photocatalyst
摘要： Herein we report a facile two-step synthetic strategy for fabricating the ternary polystyrene/reduced graphene oxide/ceria (PS/RGO@CeO2) nanocomposite particles for the first time through the self-assembly of the RGO on the surface of PS microsphere (PS/RGO) and then the attachment of CeO2 nanoparticles (NPs) onto the as-prepared PS/RGO nanocomposite particles. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis have been employed to characterize the morphology and composition of the as-prepared samples. The size and mass loading of resulting CeO2 NPs on the PS/RGO nanocomposite particles are easily tunable. Furthermore, the photocatalytic performance of as-prepared ternary nanocomposite particles towards the degradation of methylene blue is investigated. Notably, the PS/RGO@CeO2 nanocomposite particles have high photocatalytic activity due to the synergistic effect between the CeO2 NPs and RGO in such a unique structure, and moreover, they also exhibit high stability in a recyclable manner. Therefore, it can be expected that our ternary nanocomposite particles are an attractive photocatalyst candidate for various photocatalytic applications.
关键词： polystyrene microsphere,ceria nanoparticle,reduced graphene oxide,nanocomposite particle,catalysis
更新于2025-09-19 17:15:36
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Optical Properties and Model of the Electronic and Spatial Structure of Hypercrosslinked Polystyrene
摘要： A number of hypercrosslinked polystyrene networks are studied. The networks are obtained via additional crosslinking of granules of styrene copolymer with 0.5% divinylbenzene (0.3–0.5 mm) and micro-granules with 1% divinylbenzene (3.5 μm) using monochlorodimethyl ether to densities of crosslinking from 60 to 500%. It is found that as the degree of crosslinking grows, the absorption in the electronic spectrum of the polymer extends to the visible region, and the granules change color (toward as dark as black); this phenomenon is much less expressed for microgranules and milled materials. For a consistent explanation of these two observations, assumptions are made about the appearance and increase in the contrast of density fluctuations of a tracery hypercrosslinked network and light scattering on such micro-inhomogeneities in the volume of particles of the compared series of polymers.
关键词： hypercrosslinked polystyrene,network structure,electronic spectra,degree of crosslinking
更新于2025-09-19 17:15:36
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Comparison of Structural and Optical Properties for N-embedded Polycyclic and Non-embedded Cationic Phosphorescent Iridium(III) Complexes
摘要： We designed and synthesized N-embedded polycyclic based cationic Ir-NO and non-embedded complexes Ir-N and Ir-O. Single crystal structures indicate that the N-embedded polycyclic unit in Ir-NO exhibits certain planarity and induces interesting π-π-stackings between 2,2’-bipyridine moieties of one molecule and two polycyclic units of the other molecule, and their shortest intermolecular distances are both 3.24 ?, which results in a stronger structural distortion of 2,2’-bipyridine ligand with a larger torsion angel (12.70o) in comparison with those of Ir-N (5.51o) and Ir-O (8.11o). Unpredictably, both Ir-N and Ir-O show deep red emission in solution whereas Ir-NO exhibits no emission. However, all complexes show significant luminescence in their respective polystyrene (PS) films, and Ir-NO displays a longer emission lifetime than those of Ir-N and Ir-O. DFT calculations reveal that unusual ligand-to-metal charge transfer (3LMCT) excited state character can be found in Ir-NO and Ir-N, which is in contrast to metal-to-ligand charge transfer (3MLCT) excited state property in Ir-O.
关键词： iridium complexes,N-embedded polycyclic ligands,phosphorescent cationic,polystyrene films
更新于2025-09-19 17:15:36
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Silicon nanostructuring by Ag ions implantation through nanosphere lithography mask
摘要： Nanosphere lithography is an effective technique for high throughput fabrication of well-ordered patterns on large areas. This study reports on nanostructuring of silicon samples by means of Ag ions implantation through self-organized polystyrene (PS) masks. The PS nanospheres with a diameter of ～150 nm were self-assembled in a hexagonal array on top of Si(100) wafers, and then used as a mask for subsequent 60 keV silver ion implantation. Different fluences were applied up to 2 × 10^16 ions/cm^2 in order to create a distribution of different sizes and densities of buried metal nanoparticles. The surface morphology and the subsurface structures were studied by scanning electron microscopy and cross-sectional transmission electron microscopy, as a function of the mask deformation upon irradiation and the implantation parameters itself. We demonstrate that Ag is implanted into Si only through the mask openings, thus forming a regular array of amorphized regions over the wide area of silicon substrate. These fragments are of similar dimensions of the spheres with widths of about 190 nm and distributed over 60 nm in depth due to the given ion range. At the subsurface region of the implanted fragments, the synthesis of small sized and optically active Ag nanoparticles is clearly observed. The samples show a strong absorption peak in the long-wavelength region from 689 to 745 nm characteristic for surface plasmon resonance excitations, which could be fitted well using the Maxwell-Garnett`s theory.
关键词： Nanostructuring,Ag nanoparticles,SPR peak,Silicon,Polystyrene nanomask,Ion beam implantation
更新于2025-09-19 17:15:36
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Compositional Control in 2D Perovskites with Alternating Cations in the Interlayer Space for Photovoltaics with Efficiency over 18%
摘要： Microplastics (MPs) are considered as a pollutant of marine environments and have become a global environmental problem in recent years. A number of studies have demonstrated that MPs can enter the human food chain, and MPs have even been detected in human stools. Therefore, there is increasing concern about the potential risks of MPs to human and animal health. Here, we investigated maternal polystyrene MPs exposure during gestation and lactation and evaluated the potential effects on dams and the F1 (both PND 42 and 280) and F2 (PND 42) generations. The results of transcriptome and 16S rRNA sequencing indicated that MPs caused the metabolic disorder in maternal MPs associated with gut microbiota dysbiosis and gut barrier dysfunction. Simultaneously, maternal MPs exposure also had the intergenerational effects and even caused long-term metabolic consequences in the F1 and F2 generations. In addition, in F1 (PND 42), the composition of gut microbiota did not change significantly, while the hepatic transcriptome and serum metabolite changes showed the potential risk in metabolic disorder. Then, the potential of hepatic lipid accumulation was observed in adult F1 mice (PND 280), especially in the female mice. Our results demonstrated that maternal MPs exposure during gestation and lactation increases the risk of metabolic disorder, and these results provide new insight into the potential long-term hazards of MPs.
关键词： Polystyrene,Intergenerational effects,Maternal exposure,Microplastics,Metabolic disorder,Gut microbiota
更新于2025-09-19 17:13:59