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Stabilizing silver window electrodes for organic photovoltaics using a mercaptosilane monolayer
摘要： A single layer of the bifunctional molecule 3-mercaptopropyltrimethoxysilane is shown to be remarkably effective at improving the stability of optically thin silver film electrodes towards spontaneous morphological change and oxidation by airborne sulfur. Inclusion of this layer in the novel transparent electrode; WO3 (30 nm) / silver (13 nm) / sol-gel ZnO (27 nm), at the silver / ZnO interface improves the efficiency of organic photovoltaic devices using this electrode by 20%, such that the power conversion efficiency is very close to that achievable using a conventional indium-tin oxide glass electrode; 9.6 % – 0.2 % vs 10.0 % – 0.3 %, with the advantage that the silver electrode has a sheet resistance one third that of the ITO glass ((cid:3)4 Ohms sq-1). The mercaptosilane monolayer is also shown to retard silver diffusion into the ZnO layer whilst imparting a favorable (cid:3)400 meV reduction in electrode work function. In addition to its utility inside the device, this molecular layer is shown to be useful for improving the stability of the silver film electrodes in top-illuminated semi-transparent photovoltaics, since it can be deposited directly onto a completed device from the vapor phase.
关键词： organic photovoltaic,silane,transparent electrode,silver electrode,3-mercaptopropyltrimethoxysilane,Monolayer,work function,organic solar cell
更新于2025-11-03 10:59:25
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One-pot green synthesis of highly luminescent silicon nanoparticles using Citrus limon (L.) and their applications in luminescent cell imaging and antimicrobial efficacy
摘要： Strongly luminescent and water dispersible silicon nanoparticles were synthesised by one-pot synthesis from venyl-trimethoxy-silane and (3-aminopropyl)-triethoxy-silane using both chemical and green reducing agents, sodium ascorbate and Citrus limon (L.) respectively. Unlike sodium ascorbate, the reduction using lemon extracts produces smaller nanoparticles with average size of 20 and 57 nm. The antimicrobial e?cacy of the nanoparticles is examined against various microorganisms and is noted that these particles possessed antibacterial property if used in concentrations above the threshold value of 1.5 μg/ml. In addition, these silicon nanoparticles emit intense blue-green emission which is successfully utilised for the luminescent cell imaging of human white blood cells and mice epithelial cells.
关键词： Luminescence,Citrus limon (L.),Silane,Silicon nanoparticle,Cell imaging.
更新于2025-09-23 15:23:52
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IR photodissociation spectra of SixH4x-4+ (x?=?4–8): Evidence for Si H Si proton bridges
摘要： Although silane-type cations of the form SixHy+ are thought to play a significant role in plasma chemistry and astrochemistry, their structural and energetic properties are largely unexplored in the size range x ≥ 3. Herein, infrared photodissociation (IRPD) spectra of mass-selected SixHy+ with x = 4–8, specifically SixH4x-4+, are recorded in the Si–H stretch range and analyzed by dispersion-corrected density functional calculations at the B3LYP-D3/aug-cc-pVDZ level. The SixH4x-4+ ions are produced in a SiH4/H2/He plasma molecular beam expansion. The IRPD process leads to the loss of SiH4 ligands, which corresponds to the lowest-energy fragment channel. Spectral analysis of the IRPD spectra reveals that all SixH4x-4+ ions have at least one Si–H–Si bridge. The characteristic fingerprint of these three-center two-electron (3c-2e) bonds is the highly IR active antisymmetric stretch fundamental of the Si–H–Si bridge (νSiHSi) occurring in the 1600–2100 cm?1 range, whose frequency strongly depends on the structural and energetic details of the Si–H–Si bridge. Although the investigated SixH4x-4+ ions can formally be described by the formula Si2H4+(SiH4)x-2, the cluster growth is more complex. The appearance of the νSiHSi bands confirms that all considered SixH4x-4+ ions with x ≤ 5 are formed by polymerization reactions. Larger clusters (x ≥ 6) show evidence for the additional presence of weakly-bonded SiH4 ligands attached to smaller chemically-bonded core ions. Correlations of the properties of the Si–H–Si bridges (bond distances, bond angles, binding energies, Si–H stretch frequencies), which vary between strong symmetric 3c-2e chemical bonds and weak hydrogen bonds, are discussed.
关键词： Silane ions,IR spectroscopy,Structure elucidation,3c-2e bond,Si H Si bridge
更新于2025-09-23 15:23:52
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Stable Molecular Surface Modification of Nanostructured, Mesoporous Metal Oxide Photoanodes by Silane and Click Chemistry
摘要： Binding functional molecules to nanostructured mesoporous metal oxide surfaces provides a way to derivatize metal oxide semiconductors for applications in dye-sensitized photoelectrosynthesis cells (DSPECs). The commonly used anchoring groups, phosphonates and carboxylates, are unstable as surface links to oxide surfaces at neutral and high pH, leading to rapid desorption of appended molecules. A synthetically versatile molecular attachment strategy based on initial surface-modification with a silyl azide followed by click chemistry is described here. It has been used for the stable installation of surface-bound metal complexes. The resulting surfaces are highly stabilized toward complex loss with excellent thermal, photochemical, and electrochemical stabilities. The procedure involves binding 3-azidopropyltrimethoxysilane (APTMS) to nanostructured mesoporous TiO2 or tin-doped indium oxide (ITO) electrodes by silane attachment followed by azide-terminated, Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reactions with an alkyne-derivatized ruthenium(II) polypyridyl complex. The chromophore-modified electrodes display enhanced photochemical and electrochemical stabilities compared to phosphonate surface binding with extended photoelectrochemical oxidation of hydroquinone for more than ~6 h with no significant decay.
关键词： DSPECs,photostability,stability,silane chemistry,electrostability,Ru(II) polypyridyl complexes,click chemistry,Dye-sensitized,photoanode
更新于2025-09-23 15:22:29
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Hydrolysis kinetics of silane coupling agents studied by near-infrared spectroscopy plus partial least squares model
摘要： A method of Fourier transform near-infrared (FT-NIR) spectroscopy combined with partial least squares (PLS) model was successfully applied to investigate the hydrolysis kinetics of four kinds of silane coupling agents (phenyltriethoxysilane, vinyltriethoxysilane, 3-mercaptopropyltriethoxysilane, 3-chloropropyltriethoxysilane) in an acid-catalyzed EtOH system. The fast scanning speed and high sensitivity of the FT-NIR spectroscopy, and the powerful data processing ability of the PLS, enabled the method to quantitatively and accurately catch the fast changing H2O concentration during the hydrolysis processes without delay, realizing the study of the fast-paced hydrolysis reactions of the silane coupling agents. The results showed that electrophilic substitution occurred in the hydrolysis reactions, which followed second-order reactions and greatly depend on the catalyst concentration and reaction temperature. The hydrolysis rate constants, activation energy, and Arrhenius Frequency factors were gained. In conclusion, the FT-NIR PLS model is a powerful tool for hydrolysis kinetics researching of the silane coupling agents.
关键词： partial least squares,Hydrolysis kinetic,silane coupling agent,near infrared
更新于2025-09-23 15:22:29
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Luminescent silicon oxycarbide thin films obtained with monomethyl-silane by hot-wire chemical vapor deposition
摘要： The use of silicon-based materials can represent enormous advantages to develop optoelectronic devices. The preparation of luminescent silicon oxycarbide thin films deposited by the hot-wire CVD technique using monomethyl-silane as single and safer source of silicon and carbon atoms is here reported. The conditions for deposition that allow obtaining an intense emission on these thin films in a wide region of the visible spectrum at low deposition temperature without further thermal annealing are presented. When the oxygen flow rate was increased, a transition from silicon carbide to silicon oxycarbide was observed. X-ray diffraction confirms the presence of nanocrystalline material. Measurements showed that the origin of the photoluminescence may be to a combination of quantum confinement effects and defects in the silicon oxycarbide matrix, mainly those related to oxygen deficient centers and hydrogen and carbon-related defects. The obtained results are promising for the development of light emitting devices compatible with current technologies at low cost.
关键词： white luminescence,Silicon oxycarbide,HW-CVD,monomethyl-silane
更新于2025-09-23 15:21:21
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Roles of chemistry modification for laser textured metal alloys to achieve extreme surface wetting behaviors
摘要： Wetting behaviors of structured metal surfaces have received considerable attention due to the wide range of applications for commercial, industrial, and military uses as well as fundamental research interests. Due to its adaptability, precision, and ease of automation, laser-based texturing techniques are desirable platforms to create micro- and nano-structures, including laser-induced periodic surface structures, or hierarchical structures on a metal substrate. However, micro- and nanostructures alone often do not achieve the desired wettability. A subsequent surface chemistry modification method must be performed to attain target extreme wettability for laser textured metal substrates. This review aims to provide a systematic understanding of the interdependence of surface chemistry modification and physical surface structures formed during the laser-based surface engineering methods. The role of surface chemistry on top of the surface structures is presented to decide the final wetting scenario. Specifically, by controlling the surface chemistry of a laser textured surface, wetting can be modulated from extreme hydrophobicity to hydrophilicity, allowing freedom to achieve complex multi-wettability situations. In each section, we highlight the most fruitful approaches and underlying mechanisms to achieve a fitting combination of surface structures and surface chemistry. Durability and stability of the treatd surface is also discussed in corrosive and abrasive environments. Finally, challenges in current studies and prospects in future research directions of this rapidly developing field are also discussed. This review will provide a comprehensive guideline for the design of laser texturing methods and the fabrication of extreme wetting surfaces for metal alloys.
关键词： superhydrophilicity,superhydrophobicity,metal alloy,Laser surface texturing,chemistry modification,silane treatment
更新于2025-09-23 15:21:01
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A Benchmark of 300mm RP-CVD Chambers for the Low Temperature Epitaxy of Si and SiGe
摘要： we have assessed, in 300 mm Reduced Pressure – Chemical Vapour Deposition chambers from major suppliers, the advantages and drawbacks of disilane for the low temperature growth of Si and SiGe. Si growth rates are, for T < 575°C, approximately ten times higher with Si2H6 than with SiH4, which are in turn roughly ten times higher than with SiH2Cl2. For given GeH4 and Si precursor mass-flow ratios, lower Ge contents and much higher SiGe growth rates are obtained at 550°C, 20 Torr with Si2H6 than with SiH4 and especially SiH2Cl2. Growth rates (Ge concentrations) are with SiH4 and SiH2Cl2 lower (slightly lower) in Supplier A than in Supplier B chamber. The situation is the opposite with Si2H6. This is assigned to (i) a ~ 5°C offset between the two and (ii) effective precursor flows which are different, most likely due to chamber geometry differences. Growth rate activation energies and relationships linking Ge concentration to precursor mass-flow ratios are quite similar, however, making process transfer between the two rather easy. Finally, we have compared ex-situ “HF-Last” wet cleanings and in-situ surface preparation processes for Si surface conditioning prior to epitaxy. Surfaces are after the latter always under high purity N2. This results in a threshold H2 bake temperature (above which there is no O interfacial contamination anymore) which is shifted downwards by ~ 25°C (from 775°C down to 750°C). Below that threshold, O sheet concentrations are with in-situ processes typically one third those associated with “HF-Last” wet cleanings and epitaxial surfaces are smoother.
关键词： surface preparation,SiGe,silane,disilane,RP-CVD,low temperature growth,Si,dichlorosilane
更新于2025-09-23 15:21:01
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A robust covalent coupling scheme for the development of FRET aptasensor based on amino-silane modified graphene oxide
摘要： In recent years, numerous aptamers have been physisorbed on graphene oxide (GO) to develop FRET based aptasensors based on the high fluorescence quenching efficiency of GO. However, physisorbed aptasensors show poor signal reversibility and reproducibility as well as nonspecific probe displacement and thereby, are not suitable for many analytical applications. To overcome these problems when working with complex biological samples, we developed a facile and robust covalent surface functionalization technique for GO-based fluorescent aptasensors using a well studied adenosine triphosphate (ATP) binding aptamer (ABA). In the scheme, GO is first modified with amino-silane, and further with glutaraldehyde to create available carbonyl groups for the covalent attachment of a fluorophore and an amino dual modified ABA. The surface modification method was characterized by zeta potential, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The linearity, sensitivity, selectivity and reversibility of the resulting GO based covalent aptasensor was determined and systematically compared with the physisorbed aptasensor. While both sensors showed similar performance in terms of sensitivity and linearity, better selectivity and higher resistance to nonspecific probe displacement was achieved with the developed covalent ABA sensor. The surface modification technique developed here is independent from the aptamer sequence and therefore could be used universally for different analytical applications simply by changing the aptamer sequence for the target biomolecule.
关键词： aptamer,physisorption,EDC/NHS,fluorescent aptasensor,Graphene oxide,glutaraldehyde,amino-silane,covalent conjugation
更新于2025-09-23 15:21:01
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Bifunctional effects of trichloro(octyl)silane modification on the performance and stability of perovskite solar cell via microscopic characterization techniques
摘要： Passivation by small organic compounds can reduce the trap density and enhance humidity and illumination stability of perovskite solar cells (PSCs). However, the small molecule passivated on the perovskite film cannot endure harsh heat stress. Herein, we find that the trichloro(octyl)silane (TC-silane) is an excellent candidate to modify the perovskite surface and grain boundary nondestructively through the formation of heat-resistive silicone layer, leading to comprehensive improvement of efficiency and stability with low cost as well as facile fabrication. The silane is a type of solvent and can be upscaled by solution process in the device. TC- silicone can crosslink the grain boundaries through hydrolytic condensation. The crosslinking silicone can resist the moisture and heat stresses to enhance the stability. Besides, micro-photoluminescence reveals that TC-silane treatment can passivate the perovskite film and enhance the optoelectronic properties through chloride replenishment during releasing hydrogen chloride molecule in the hydrolytic reaction. By utilizing Kevin probe force microscopy, we further uncover that TC-silane forms a dipole layer to facilitate the charge separation. TC-silane passivated PSCs delivers a champion efficiency of 20.03% and remains 80% of initial efficiency for more than 800 h at 70-80% relative humidity in air and for about 80 h under 85 oC thermal stress without encapsulation.
关键词： perovskite solar cell,microscopic characterization,silane passivation,stability,bifunctional effect
更新于2025-09-23 15:19:57