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AIP Conference Proceedings [Author(s) INTERNATIONAL CONFERENCE ON INVENTIVE MATERIAL SCIENCE APPLICATIONS: ICIMA-2018 - Tamil Nadu, India (27–28 September 2018)] - The effect of the ZnO thickness layer on the porous silicon properties deposited by chemical vapor deposition
摘要： We report on the properties of porous silicon deposited by Electro-Chemical Etching (ECE) technique with ZnO nanoparticles layer grown on porous silicon (P-type) by Chemical Vapor Deposition (CVD). X-ray diffraction study on the crystallographic structure revealed a beneficial impact of ZnO films on the structural properties of the porous silicon. Moreover, these properties enhanced when the ZnO layer thickness was increased. The morphological properties of ZnO/PSi were investigated based on Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) measurements. The results indicate an upgrading in the structural stability of PSi substrate with crystalline growth of ZnO thin film. It is also observed that the value of the roughness (RMS) increases when ZnO filme on PSi increases. All these results indicate that the interested ZnO shows a good and homogenous layer using (CVD) technique. Finally, it is evident that porous silicon substrate can open the door for improving the crystalline quality in hexagonal lattice of ZnO thin film, and this could be due to sponge-like structure of porous silicon.
关键词： ZnO,porous silicon,SEM,Chemical Vapor Deposition,AFM,Electro-Chemical Etching,XRD
更新于2025-09-10 09:29:36
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Recent Advances in Porous Ceramics || Physical Properties of Porous Pure and Zr/Sn-Doped Nanocrystalline BaTiO3 Ceramics
摘要： Polycrystalline BaTiO3 and Ba(Ti0.96SnxZr0.04-x)O3 ceramics (x=0.02-0.04) were prepared by a combination of solid-state and mechanochemical process and characterized at room temperature by X-ray diffraction for phase composition. Their crystal structures were found to be of the cubic and tetragonal symmetries, respectively. The grain size and porosity which were determined using Field Emission Scanning Electron Microscope (FESEM) and densitometer, respectively showed decrease and increase of relative density respectively, with increase in doping concentration. The variations of dielectric constant and loss with frequency and temperature show a maximum dielectric constant of 1660 at room temperature for Ba(Ti0.96Sn0.03Zr0.01)O3. The remnant polarization (Pr) and coercive field (Ec) of BT were found to be 581.73 V/cm and 0.27 μC/cm2. Increase in Sn content led to an increase in Pr of 0.58, 3.07, 3.73 C/cm2, and Ec of 1766.8, 2855.7, 2661.1 V/cm, respectively and are expected to lead to a significant reduction in the thickness of the multilayer ceramic capacitors. Impedance spectroscopy of polycrystalline Ba(Ti0.96Sn0.02Zr0.02)O3 in a wide frequency and temperature range showed Nyquist plots with presence of grain and grain boundary at 400°C and a negative temperature coefficient of resistance (NTCR) for Ba(Ti0.96Sn0.02Zr0.02)O3. The dielectric relaxation showed a non-Debye character.
关键词： porous ceramics,barium titanate,doping,MLCC,ferroelectrics
更新于2025-09-10 09:29:36
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<i>(Invited)</i> Water Transport Along Si/Si Direct Wafer Bonding Interfaces
摘要： The transport of water in a highly confined gap made by the direct bonding of low roughness silicon hydrophilic wafers is studied. We derive the equation for the transport of water from chemical potential gradients, using Stokes and conservation equations. The transport equation is found to be a Porous Medium Equation with exponent 2. A solution for this equation with stepwise boundary conditions is given. The model is tested against different initial conditions for inward and outward flow, and different temperatures and humidity levels.
关键词： silicon direct bonding,chemical potential gradients,Porous Medium Equation,water transport,hydrophilic wafers
更新于2025-09-10 09:29:36
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One step to prepare CNTs modified porous g-C3N4 with excellent visible-light photocatalytic performance
摘要： A kind of carbon nanotubes (CNTs) modified porous graphitic carbon nitride (CNTs/pg-C3N4) photocatalyst was successfully synthesized via one step thermal polycondensation and completely measured by some instruments, such as XRD, FTIR, TEM, BET, DRS, PL, etc. And the relevant experimental data indicated that loaded CNTs could be beneficial to the photoinduced charges transfer, facilitating photoinduced charge separation rate. Meanwhile, surface area and visible light adsorption of CNTs/pg-C3N4 photocatalyst could be increased and improved. These synergetic effects resulted in the as-synthesized CNTs/pg-C3N4 photocatalyst exhibiting better visible-light-induced photocatalytic performance for organic pollutant degradation and the product of clean energy than bulk g-C3N4, pg-C3N4 and CNTs modified bulk g-C3N4, and excellent stable photocatalytic performance was also observed after several recycling experiments. Finally, a reasonable improved photocatalytic reaction mechanism for CNTs/pg-C3N4 photocatalyst is presented.
关键词： Porous graphitic carbon nitride,Photocatalytic performance,Carbon nanotubes,Photocatalyst,Visible-light
更新于2025-09-10 09:29:36
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Effect of porous silicon substrate on structural, mechanical and optical properties of MOCVD and ALD ruthenium oxide nanolayers
摘要： Ruthenium oxide (RuO2) has received significant attention in recent years for its photocatalytic properties and photoelectrochemical (PEC) performance. In the present research, RuO2 nanolayers were grown on n-type porous silicon (PSi) by metal organic chemical vapor deposition (MOCVD) and atomic layer deposition (ALD). The morphology, mechanical and optical properties of produced nanostructures were studied by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, diffuse reflectance and photoluminescence (PL) spectroscopy. It was shown that that MOCVD gives non-uniform distribution of RuO2 along the pore and it is deposited mainly in the near-surface of PSi, while distribution of ruthenium obtained by ALD looks conformal over the entire pore. The mean size of RuO2 nanocrystallites and mechanical stresses were determined by TEM, XRD and Raman spectroscopy. It was demonstrated that samples obtained by ALD demonstrate a good crystallinity, while crystalline phase for samples produced by MOCVD improve with RuO2 layer thickness increasing. It was established the formation of hydrated RuO2 during ALD and MOCVD. It was shown that the samples produced by MOCVD have slightly higher electrical conductivity than ALD samples. The average value of energy gap (Eg) for samples prepared by MOCVD depended on the number of injections. RuO2 nanolayers quenched intrinsic PL from the PSi matrix. The correlation between structural, optical, and mechanical properties of samples produced by MOCVD and ALD was discussed.
关键词： MOCVD.,ruthenium oxide,ALD,porous silicon
更新于2025-09-10 09:29:36
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On-substrate porous-anodic-alumina-assisted gold nanostructure arrays: Meeting the challenges of various sizes and interfaces
摘要： Arrays of 0- and 1-dimentional noble-metal nanostructures aligned on solid substrates are in demand for nanocatalysis, bio- and optical sensing, or biomolecular analysis. Here we introduce a range of advances based on a systematic research towards the porous-anodic-alumina (PAA)-assisted on- substrate arrays of gold nanostructures, such as rods and spheres, spatially-separated and highly aligned on a metal or semiconductor supporting layer via a blend of the anodizing, re-anodizing, and post- anodizing treatments applied to a thin layer of Al superimposed on selected valve metals (W, Ti, Hf), metal bilayers (W/Ti), or binary metal alloy layers (W-Ti). The achievements are due to (1) the improved self-organization in the PAA thin films during the self-localizing high-current anodization of the upper Al layer at challenging potentials ranging 100 to 250 V and 20 to 5 V, and (2) the enhanced penetration of the alumina barrier layer by the undergrowing metal oxide due to the increasing polarization (re- anodizing). The protrusions of the undergrown metal oxide can be either selectively dissolved away providing perfect nanoholes in the alumina barrier layer or left as formed in the barrier layer and annealed in vacuum to increase their electron conductance and serve as the supports for subsequent metal electrodeposition. Additionally, the in-situ amplitude-modulated constant-current pulse deposition mode combined with the original surface-wiping technique to remove the overdeposited gold allow for smooth nucleation and uniform finishing of perfect arrays of on-substrate gold nanospheres and nanorods, having diameters from 10 to over 250 nm and length up to 2.5 ?m.
关键词： gold nanorods,electrodeposition,barrier layer dissolution,nanodots,porous anodic alumina
更新于2025-09-10 09:29:36
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Tuning in BiVO4/Bi4V2O10 porous heterophase nanospheres for synergistic photocatalytic degradation of organic pollutants
摘要： Heterophase junction construction is a powerful means of inhibiting recombination of photoinduced charge carriers. Herein, we prepared BiVO4/Bi4V2O10 porous heterophase nanospheres assembled by nanoflakes through a facile solvothermal process. The crystal structure of the porous nanospheres can be easily regulated from mixed phase of BiVO4 and Bi4V2O10 to pure BiVO4 by changing the solvothermal reaction time. The formation of heterophase junction BiVO4/Bi4V2O10 can greatly enhance the transfer and separation rate of photogenerated charge carriers. Meanwhile, the porous nanoflake-based nanosphere structure can enhance visible light utilization and organic pollutants adsorption. Benefiting from the synergy effects of these positive factors, the optimal BiVO4/Bi4V2O10 exhibits excellent visible light photocatalytic performance and cycling capability for the degradation of organic pollutants.
关键词： porous nanospheres,heterophase junction,pollutants degradation,BiVO4/Bi4V2O10,visible light photocatalysis
更新于2025-09-10 09:29:36
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Tailoring of highly porous SnO2 and SnO2-Pd thin films
摘要： Tin oxide is a material that attracts attention due to varieties of technological applications. The main parameters that influence its properties are morphology, crystalline structure and stoichiometry. To influence these parameters researchers try to develop nanostructured thin films that would conform technological application. Here, we report the preparation and characterization of highly porous SnO2 and Pd doped SnO2 thin films. The films were deposited in form of nanorods with controllable geometry. Such morphology was achieved by utilizing glancing angle deposition (GLAD) with assisted magnetron sputtering. This arrangement allowed preparation of slanted pillars, zig-zag structure, vertically standing posts, spiral posts and “bush”-like structures. We calculated that slanted pillars possess highest surface area among the films listed. Then, sets of slanted pillars were deposited and studied in more details. The influence of substrate annealing during the film deposition and Pd doping on the morphology, crystalline structure and stoichiometry of the films are discussed. Characterizations of the tin oxide films were performed by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and synchrotron radiation photoelectron spectroscopy (SRPES). GLAD with assisted magnetron sputtering allowed us to deposit broad range of SnO2 nanostructures while annealing of the substrate during deposition affects the films crystallinity. Also, we find that doping of the SnO2 films with Pd leads to alloy phase formation. These findings can be applied in variety of applications including gas sensing, catalysis, optics and electronics.
关键词： XPS,SRPES,SnO2,tin oxide,glancing angle deposition,TEM,HRTEM,GLAD,highly porous
更新于2025-09-10 09:29:36
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Precise Micropatterning of a Porous Poly(Ionic Liquid) via Maskless Photolithography for High-Performance Non-Enzymatic H2O2 Sensing
摘要： Porous poly(ionic liquid)s (PILs) recently have been actively serving as a multifunctional, interdisciplinary materials platform in quite a few research areas, including separation, catalysis, actuator, sensor, and energy storage, just to name a few. In this context, the capability to photo-pattern PIL microstructures in a porous state on a substrate is still missing but is a crucial step for their real industrial usage. Here, we developed a method for in situ rapid patterning of porous PIL microstructures via a maskless photolithography approach coupled with a simple electrostatic complexation treatment. This breakthrough enables designs of miniaturized sensors. As exemplified in this work, upon loading Pt nanoparticles into porous PIL microstructures, the hybrid sensor showed outstanding performance, bearing both a high sensitivity and a wide detection range.
关键词： nanoparticles,maskless photolithography,poly(ionic liquid),H2O2 sensors,porous microstructures
更新于2025-09-10 09:29:36
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Influence of the Tb3+ concentration on the luminescent properties of high silica glass
摘要： Tb3+- doped high silica glass was prepared by sintering porous glass. The density, valence state and amount of Tb, transmittance, photoexcitation spectra, photoluminescence spectra, and cathodoluminescence spectra (CL) were recorded and the luminescence decay kinetics analyzed in details. These results show that the doping concentration in high silica glass is in direct proportion to the concentration in solution, and the density increases with the increasing concentration of rare earth ions as well as the intensity of emission spectrum. The largest emission intensity of 0.2 mol/L is more than 2 times higher than the intensity of the 0.05 mol/L. Besides, the “red” shift phenomenon could be distinguished clearly in the transmittance spectra. There is a broad band at the “red” region in the CL spectra. The decay time which is in the millisecond range in di?erent spectral range were measured and analyzed revealing that the decay time of 5D3 is shorter than that of 5D4.
关键词： Luminescent properties,Rare earth ions,High silica porous glass
更新于2025-09-10 09:29:36