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A new non-centrosymmetric Chlorobismuthate(III) hybrid material: Crystal structure, optical properties and antibacterial study
摘要： As part of our interest in organic-inorganic metallate complexes, we had prepared a novel non-centrosymmetric chlorobismuthate (III) compound with the chemical formula (C6H7NCl)3 [BiCl6]$H2O, by slow evaporation method at room temperature. It was characterized by single crystal X-ray diffraction (SCXRD), X-ray powder diffraction (PXRD), spectroscopic measurements, thermal study, Hirshfeld surface analysis, DFT investigation, and antimicrobial activity. A preliminary SCXRD structural analysis revealed that the compound crystallizes in the Orthorhombic system (P212121 space group) with the following unit cell parameters a ? 7.3432 (1) ?, b ? 13.8257 (2) ? and c ? 28.2140 (5) ? with Z ? 4 and V ? 2864.42 (8) ?3. The examination of the structure shows that its atomic arrangement can be described as inorganic [BiCl6]3- units isolated from each other by the organic cations and the co-crystallized water molecules. The cohesion between these entities is performed via the NeH/Cl, NeH/O, CeH/O, CeH/Cl, and OeH/Cl hydrogen bonding interactions between the 4-dichloroanilinium cations, the [BiCl6]3- anions and water molecules forming a 3D network. The Hirshfeld surface calculation was conducted to investigate: intermolecular interactions, associated 2D ?ngerprint plots, and enrichment ratio, indicating the relative contribution of these interactions in the crystal structure quantitatively. Thermal analysis reveals the decomposition of the compound at 180 (cid:2)C. The quantum mechanical calculations such as geometry optimization, vibrational frequencies, simulated UVeVisible spectrum, FMOs analysis were made together with the experimental studies. Furthermore, the new synthesized compound was screened for its antibacterial activity. Results revealed that it has the most effective activity against all the tested bacteria compared to the amine alone and to the BiOCl.
关键词： Hirshfeld surface analysis,Hybrid material,DFT calculations,Hexachlorobismuthate(III),X-ray diffraction,Antimicrobial activity
更新于2025-09-23 15:23:52
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Morphological study of InGaN on GaN substrate by supersaturation
摘要： The morphology of thin InGaN layers grown on c-plane GaN substrates by metalorganic vapor phase epitaxy (MOVPE) has been studied by atomic force microscopy. Three different morphologies appeared, a stepped surface, large flat two-dimensional (2D) islands and small high three-dimensional (3D) dots. Low growth temperature and high growth rate (i.e. increased vapor supersaturation) changed the InGaN morphology from steps to 2D islands and then 3D dots (when exceeding the critical thickness for 3D dots). Larger miscut angle of GaN substrate changed the morphology from 2D islands to step by decreasing the surface supersaturation of individual terraces. InGaN layers with a stepped morphology had the highest internal quantum efficiency at similar InN mole fraction. InGaN grown on GaN substrate more easily achieved a stepped morphology compared to InGaN on GaN/sapphire templates.
关键词： A3. Metalorganic vapor phase epitaxy,B2. Semiconducting III-V materials,A1. Crystal morphology,B1. Nitride
更新于2025-09-23 15:22:29
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Second Derivative Spectrophotometric Determination of Iron(II) and Ruthenium(III) Using 1, 10-phenanthroline
摘要： A simple and sensitive derivative spectrophotometric method has been developed for the determination of Fe(II) and Ru(III) using the baseline to peak measurement techniques. In the present method 1,10-phenanthroline (o-phen) used as a complexing agent. Fe(II) and Ru(III) forms a complex with o-phen at pH 5 and 4, respectively. Based on baseline-to-peak measurement techniques deep red Fe(II)-o-phen complex shows the maximum peak at 535 nm, while the yellow product of Ru(II) - o-phen complex at 466 nm. Beer’s law obeyed in the range of 0.1 - 2.0 μg mL-1 for Fe(II) and 5.0 - 20.0 μg mL-1 for Ru(III) which is supported by correlation coefficient 0.99853 and 0.99914, respectively. The present method has been applied successfully for the determination of Fe (II) in pharmaceutical formulations and Ru(III) in some synthetic mixtures.
关键词： Iron(II),Second Derivative Spectra,Ruthenium(III),1,10-Phenanthroline
更新于2025-09-23 15:22:29
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InAs/GaSb thin layers directly grown on nominal (001)-Si substrate by MOVPE for the fabrication of InAs FINFET
摘要： We demonstrated the fabrication of a densely packed InAs fins network for nanoelectronic applications. High crystalline quality GaSb/InAs layers have been grown directly on 300 mm nominal (001)-Si substrate. The InAs was then processed by etching step using a lithographic mask based on block copolymer to obtain sub-20nm width fins. This block copolymer has been optimized to self-assemble into lamellar structure with a period of 30nm, standing perpendicular to the substrate thanks to a neutral layer. STEM-HAADF characterization displays vertical sidewalls InAs fins with a width as low as 15nm spaced by almost 10nm. Early electrical characterizations exhibit a current flow through the connected fins.
关键词： B3 High electron mobility transistors,B3 Field effect transistors,A3 Organometallic vapor phase epitaxy,A1 Etching,B2 Semiconducting III-V materials
更新于2025-09-23 15:22:29
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Luminescent TOP Nanosensors for Simultaneously Measuring Temperature, Oxygen, and pH at a Single Excitation Wavelength
摘要： Two nanosensors for simultaneous optical measurements of the bioanalytically and biologically relevant analytes temperature (“T”), oxygen (“O”), and pH (“P”) have been designed. These “TOP” nanosensors are based on 100 nm-sized silica-coated polystyrene nanoparticles (PS-NPs) doped with a near infrared emissive oxygen- and temperature-sensitive chromium(III) complex ([Cr(ddpd)2][BPh4]3, CrBPh4) and an inert reference dye (Nile Red, NR or 5,10,15,20-tetrakis-(pentafluorophenyl) porphyrin, TFPP) and are covalently labeled with pH-sensitive fluorescein isothiocyanate (FITC). These emitters can be excited at the same wavelength and reveal spectrally distinguishable emission bands allowing for ratiometric intensity-based and time-resolved studies in the visible and near infrared wavelength region. Studies in PBS buffer solutions and in a model body liquid demonstrate the applicability of these nanosensors for the sensitive fluorescence readout of TOP simultaneously at the same position.
关键词： lifetime,fluorescence,chromium(III) complex,oxygen/pH/temperature biosensor,optical multianalyte nanosensors,phosphorescence
更新于2025-09-23 15:22:29
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Selective Area Deposition of Hot Filament CVD Diamond on 100 mm MOCVD Grown AlGaN/GaN Wafers
摘要： A new technique is reported for selective growth of polycrystalline diamond by hot filament chemical vapor deposition (HFCVD) on AlGaN/GaN-on-Si (111) wafers without degradation of the underlying layers. Selective diamond seeding is accomplished by dispersing nano-diamond seeds in photoresist and patterned lithographically prior to HFCVD growth. A thin layer of plasma enhanced CVD SiNx, deposited prior to seeding and diamond deposition, was found to be essential to protect the AlGaN/GaN wafer. Methane concentration of 3.0% was used to achieve increased diamond growth rate and faster surface coverage. Excellent selectivity and minimal AlGaN surface damage were achieved due to the protective layer and faster surface coverage with increased methane concentration. Damage mitigation was confirmed by comparison of atomic force microscopy, x-ray diffraction, and Raman spectroscopy, each conducted before and after diamond deposition, and by SEM images of the final structures.
关键词： 2DEG,Reciprocal space mapping,III-Nitride,SiNx,Selective area deposition,CVD diamond,Photolithography,GaN decomposition
更新于2025-09-23 15:22:29
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InGaAs FinFETs Directly Integrated on Silicon by Selective Growth in Oxide Cavities
摘要： III-V semiconductors are being considered as promising candidates to replace silicon channel for low-power logic and RF applications in advanced technology nodes. InGaAs is particularly suitable as the channel material in n-type metal-oxide-semiconductor field-effect transistors (MOSFETs), due to its high electron mobility. In the present work, we report on InGaAs FinFETs monolithically integrated on silicon substrates. The InGaAs channels are created by metal–organic chemical vapor deposition (MOCVD) epitaxial growth within oxide cavities, a technique referred to as template-assisted selective epitaxy (TASE), which allows for the local integration of different III-V semiconductors on silicon. FinFETs with a gate length down to 20nm are fabricated based on a CMOS-compatible replacement-metal-gate process flow. This includes self-aligned source-drain n+ InGaAs regrown contacts as well as 4 nm source-drain spacers for gate-contacts isolation. The InGaAs material was examined by scanning transmission electron microscopy (STEM) and the epitaxial structures showed good crystal quality. Furthermore, we demonstrate a controlled InGaAs digital etching process to create doped extensions underneath the source-drain spacer regions. We report a device with gate length of 90 nm and fin width of 40 nm showing on-current of 100 μA/μm and subthreshold slope of about 85 mV/dec.
关键词： Integration,MOSFETs,TASE,III-V
更新于2025-09-23 15:22:29
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Synthesis and Electrical Transport Properties of CuInGaTe2
摘要： Copper Indium Gallium di-telluride (CIGT) single crystals were synthesized by a special modified Bridgman technique for crystal growth. Our XRD patterns clearly exhibited single phase. The temperature dependence of the electrical conductivity σ(T), Hall coefficient RH(T) in CuInGaTe2 single crystals have been demonstrated over the temperature range 143-558 K for the first time. The Hall coefficient sign confirms the samples displays the p-type conducting. The temperature dependence of the conductivity, Hall coefficient, Hall mobility, and charge carriers concentration were investigated were presented with a clear and effective pictures. CuInGaTe2 single crystals revealed electrical band gaps (or "transport gaps") ranging from 0.64 eV to 0.85 eV. The results obtained from electrical conductivity and carrier concentration revealed the sample p-type with acceptor energy level equal to ≈ 0.027 eV. From the obtained experimental data, the main fundamental physical constants and others for crystals under consideration have been estimated.
关键词： Single crystals,Electrical conductivity,Cu–III–VI2 Chalcopyrite semiconductors
更新于2025-09-23 15:22:29
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Zinc blende and wurtzite crystal structure formation in gold catalyzed InGaAs nanowires
摘要： III-V semiconductor nanowires made of materials which have the zinc blende crystal structure in bulk are well known to exhibit either the zinc blende or the wurtzite crystal structure. Understanding and controlling which crystal structure that forms is of highest importance for nanowire applications in a variety of areas. In addition to this, composition control in ternary nanowires is another key technology area for successful nanowire applications. We derive a general model, based on two-component nucleation theory, which we use to explain the so far less understood experimental observations of zinc blende, wurtzite, and mixed crystal structure as a function of growth conditions and composition, x, in gold catalyzed InxGa1-xAs nanowires. An interesting theoretical finding is that the wurtzite and zinc blende phases have different compositions, even if they are nucleated from the same catalyst particle at the same conditions.
关键词： A1. Nanostructures,A1. Nucleation,A1. Crystal structure,B2. Semiconducting III-V materials,B2. Semiconducting ternary compounds
更新于2025-09-23 15:22:29
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Fabrication of AlN templates on SiC substrates by sputtering-deposition and high-temperature annealing
摘要： High-quality AlN templates fabricated by sputtering-deposition and post-deposition high-temperature annealing have great potential for deep ultraviolet light-emitting device applications. In this work, we fabricated AlN films on 6H-SiC substrates by sputtering and face-to-face annealing and characterized the structural quality of the AlN films before and after annealing. As reported in previous studies, to accomplish high-quality AlN films on SiC substrates using conventional methods, such as molecular beam epitaxy or metalorganic vapor phase epitaxy (MOVPE), it is important to grow the AlN on the SiC coherently. However, in this work, although the annealed AlN films were fully relaxed from the SiC substrates, or even had tensile strain, the AlN films indicated high crystallinity. The X-ray rocking curve full width at half maximum (XRC-FWHM) values of the 200-nm-thick annealed AlN film were 17 and 246 arcsec for the AlN (0002) and (10–12) diffraction, respectively. Though the annealed AlN film indicated rough surfaces with bunched step structures, the surface morphology was remarkably improved by MOVPE growth and clear atomic step-and-terrace structures were formed. The XRC-FWHM values of the MOVPE-grown AlN were 90 and 239 arcsec for the AlN (0002) and (10–12) diffraction, respectively.
关键词： A1. Stresses,A1. Atomic force microscopy,B1. Nitrides,B2. Semiconducting III-V materials,A1. X-ray diffraction
更新于2025-09-23 15:22:29