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Improving Performance and Stability of Planar Perovskite Solar Cells through Grain Boundary Passivation with Block Copolymers
摘要： Al2O3–ZrO2 ceramic coatings were fabricated on titanium alloy substrate by ultrasonic assisted laser cladding. The effects of ultrasonic on the microstructure and mechanical properties of the coatings are investigated through experiments. A novel laser cladding method by ultrasonic assisted is used in this paper. In this method, ultrasonic waves are directly applied on the micro-zone of molten pool. Experimental results indicated that the grain size and mechanical properties of the coatings are improved with the ultrasonic assisted. The amount of coatings cracks are decreased due to the application of ultrasonic vibration in the laser cladding.
关键词： Al2O3–ZrO2 ceramics,ultrasonic,laser cladding,mechanical properties
更新于2025-09-11 14:15:04
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A nonlinear ultrasonic method for real-time bolt looseness monitoring using PZT transducer–enabled vibro-acoustic modulation
摘要： A real-time nonlinear ultrasonic method based on vibro-acoustic modulation is applied to monitor early bolt looseness quantitatively by using piezoceramic transducers. In addition to the ability to detect the early bolt looseness, a major contribution is that we replaced the shaker, which is commonly used in a vibro-acoustic modulation method, by a permanently installed and low-cost lead zirconate titanate patch. In vibro-acoustic modulation, when stimulating two input waves with distinctive frequencies, namely the high-frequency probing wave and the low-frequency pumping wave, the high-frequency probing wave will be modulated by the low-frequency pumping wave to generate sidebands in terms of bolt looseness. Thus, the influence of low-frequency voltage amplitudes on the modulation results, which is ambiguous in previous research, is also analyzed in this article. The results of experiment demonstrated that the lead zirconate titanate–enabled vibro-acoustic modulation method is reliable and easy to implement to identify the bolt looseness continuously and quantitatively. In addition, low-frequency amplitudes of actuating voltage should be selected in a reasonable range. Finally, we compared the vibro-acoustic modulation method with the time-reversal method based on the linear ultrasonic theory, and the result illustrates that vibro-acoustic modulation method has better performance in monitoring the early bolt looseness.
关键词： structural health monitoring,time-reversal,lead zirconate titanate transducers,Bolt looseness,vibro-acoustic modulation,nonlinear ultrasonic
更新于2025-09-11 14:15:04
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Structure–Activity/Stability Correlations from the Electrochemical Dynamic Responses of Titanium Anode Coatings Formed of Ordered TiO <sub/>2</sub> @RuO <sub/>2</sub> Microspheres
摘要： Spherical TiO2/RuO2 particles were synthesized by ultrasonic spray pyrolysis (USP) at 200 and 800?C. The activity for the oxygen and chlorine evolution reactions (OER and CER, respectively) and the dynamic responses from electrochemical impedance spectroscopy (EIS) of the USP powders, as well as of the corresponding coatings on Ti, were analyzed and are discussed. The loss of coating activity is discussed with respect to the differences in the EIS and cyclic voltammetry responses of the coatings in their active and inactive states. The 800?C-USP sample was found to be more active than the 200?C-USP sample for both the CER and the OER, whereas the stability of the former was considerably lower. The correlation between the structure, composition and morphology of the powder and the coating with the registered electrochemical properties is discussed. The EIS analysis of the coating resistance distributions induced by the thermal treatment of the powder indicated a complex combination of the pore resistance and the pseudocapacitive charge transfer resistance. An additional coating resistance, due to loose grain boundaries, was introduced into the coatings in their active and inactive state. The EIS analysis indicated the changes in TiO2-enriched core/RuO2-enriched shell structure, caused by the USP temperature.
关键词： TiO2/RuO2,cyclic voltammetry,electrochemical impedance spectroscopy,oxygen evolution reaction,chlorine evolution reaction,ultrasonic spray pyrolysis,coating stability
更新于2025-09-11 14:15:04
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[IEEE 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Singapore (2018.7.16-2018.7.19)] 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Application to a Failure Analysis of Ultrasonic Beam Induced Resistance Change (SOBIRCH)
摘要： Failure analysis of the semiconductor device has the demand that the inspection should be performed without mold decapsulation. Conventional PEM(Photo Emission Microscope) and IR-OBIRCH(InfraRed Optical Beam Induced Resistance Change) cannot analyze in package state because the emission light and stimulation light for IR-OBIRCH cannot be transmitted through package mold. We developed new technique for package failure analysis based on ultrasonic stimulation. We named this technique as SOBIRCH(ultraSOnic Beam Induced Resistance Change). In this report, we describe the detection example of actual package IC and multilayer chip.
关键词： LIT,package failure analysis,ultrasonic,SOBIRCH,ultrasonic stimulation,IR-OBIRCH
更新于2025-09-10 09:29:36
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Annealing Impact on Interface Properties of Sprayed Al2O3-Based MIS Structure for Silicon Surface Passivation
摘要： Aluminum oxide (Al2O3) films of different thicknesses were deposited on quartz and silicon (100) substrates by an ultrasonic spray method from a solution of aluminum acetylacetonate dissolved in N,N-dimethylformamide with different molar concentrations. The optical, morphological and electrical properties were investigated. Increasing the molar concentration leads to a refractive index decrease, an increase in the optical band gap from 5.26 eV to 5.52 eV and a change in the surface roughness of the films. The electrical parameters at the Al2O3/Si interface such as the flat band voltage (VFB), effective charge density (Qeff) and interface trap density (Dit) were explored as a function of the molar concentration, film thickness and heat treatment. The latter, done by two annealing processes, namely, the post deposition annealing (PDA) and post metallization annealing (PMA) on the structure, lead to remarkable interface properties. It was found that the positive flat band voltage VFB shift is correlated with the generation of negative effective charge during PMA. A decrease of the Dit distribution in the PMA samples with no significant effect in the case of PDA samples was clearly observed for different molar concentrations. Furthermore, as the Al2O3 film thickness decreases, Dit decreases in both PDA and PMA samples while the relatively high density Qeff and its negative charge polarity were obtained for thinner films. A noticeable passivation effect on the Al2O3/Si interface has been confirmed on samples that underwent the annealing process. These findings related specifically to the interface properties are promising for silicon surface passivation, in particular for solar cells applications.
关键词： Al2O3,surface passivation,ultrasonic spray,post-metallization annealing,post-deposition annealing
更新于2025-09-10 09:29:36
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CUDA-based Volume Rendering and Inspection for Time-varying Ultrasonic Testing Datasets
摘要： We present a framework for time-varying 3D UT datasets based on volume real-time CUDA-based rendering with high quality. In addition, we design a novel trapezoid-shaped transfer functions (TF) with color gradient. Furthermore, we propose an interactive 3D inspection method via clipping plane with enhanced ability of the cross-section data.
关键词： Clipping Plane,Volume Rendering,Ultrasonic Testing,Transfer Function,CUDA,Time-varying Datasets
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP) - Hiroshima (2018.5.27-2018.6.1)] 2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP) - Bi<inf>4</inf>Ti<inf>3</inf>O<inf>12</inf>/SrTiO<inf>3</inf>Sol-Gel Composite for Ultrasonic Transducers
摘要： In this study, lead-free new sol-gel composite, Bi4Ti3O12(BiT)/SrTiO3(ST) was developed. 100μm thick films were fabricated on 3mm thick titanium substrates by sol-gel spray technique. Polarization process was carried out at room temperature and 400°C. Samples were set onto a hot plate and ultrasonic response in pulse-echo mode was recorded by a digital oscilloscope from room temperature to 500°C. As a result, each samples showed reflected wave at 500°C. Therefore, BiT/ST sol-gel composite have high temperature endurance up to 500°C. In addition, BiT/ST films was able to polarize at room temperature.
关键词： ultrasonic transducer,high temperature,nondestructive testing,sol-gel composite
更新于2025-09-10 09:29:36
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Flexible piezoelectric ultrasonic energy harvester array for bio-implantable wireless generator
摘要： Ultrasonic driven wireless charging technology has recently attracted much attention in the next generation bio-implantable systems; however, most developed ultrasonic energy harvesters are bulky and rigid and cannot be applied to general complex surfaces. Here, a flexible piezoelectric ultrasonic energy harvester (PUEH) array was designed and fabricated by integrating a large number of piezoelectric active elements with multilayered flexible electrodes in an elastomer membrane. The developed flexible PUEH device can be driven by the ultrasonic wave to produce continuous voltage and current outputs on both planar and curved surfaces, reaching output signals of more than 2 Vpp and 4 μA, respectively. Potential applications of using the flexible PUEH to charge energy-storage devices and power commercial electronics were demonstrated. Its low attenuation performance was also evaluated using the in vitro test of transmitting power through pork tissue, demonstrating its potential use in the next generation of wirelessly powered bio-implantable micro-devices.
关键词： piezoelectric,ultrasonic energy harvester,wireless generator.,flexible device
更新于2025-09-10 09:29:36
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Elastic moduli of TeO2–PbO glass system
摘要： Binary glasses (1 ? x)(TeO2) ? x(PbO) with x = 0, 0.10, 0.15, 0.20, 0.25, 0.30 mol% prepared using the melt quenching have been studied in this work. The amorphous nature of the glasses is confirmed by XRD analyses. Density, ρ and molar volume, Vm were measured for more information on structural changes. The ultrasonic velocities (longitudinal and shear) were obtained using the method of pulse-echo at 5 MHz resonating frequency. The elastic moduli, namely longitudinal (L), shear (G), Young (E) and the bulk (K) moduli were obtained from the density and ultrasonic velocities measurement. The softening temperature (TS), Debye temperature (θD), Poisson’s ratio (σ), fractal bond connectivity (d), microhardness (H) and acoustic impedance (Z) were obtained from the elastic moduli. The transition temperature ( Tg ) and thermal expansion coefficient (αP) were also calculated. The experimental elastic moduli data and the values calculated theoretically from the bond compression, Makishima–Mackenzie, and Rocherulle models were compared in this work.
关键词： Tellurite glasses,Thermal properties,Ultrasonic velocities,Elastic moduli,PbO
更新于2025-09-09 09:28:46
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Reference Module in Materials Science and Materials Engineering || Piezoelectric Ultrasonic Motors
摘要： In general, piezoelectric ultrasonic motors (USMs) contain two basic components that are the stator and the rotor. Piezoelectric and elastic materials in a stator are combined in various ways forming a composite structure. Exciting at least two orthogonal mechanical vibration modes of the composite stator using single or orthogonal multiple high-frequency a.c. signals generates mechanical elliptical motion on the stator surface. The rotor is pressed against the stator's surface and a rotation is produced by frictional interaction between the touching stator and rotor surfaces.
关键词： Stator,Piezoelectric,Rotor,Frictional Interaction,Ultrasonic Motors
更新于2025-09-09 09:28:46