 Subjects -> ELECTRONICS (Total: 207 journals)
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- Contact Area of Electrification Materials Relating to Triboelectric
Generators: A Comparative Study-
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Abstract: Triboelectric generators (TEGs) stemming from the triboelectric phenomena, are promising for energy harvesting due to their high output power and efficiency. Analysis of the tribo material selection for TEGs has suggested that energy generation is linked to heterogeneous and homogeneous materials found at opposite ends of the triboelectric series. Current research has identified that the triboelectric phenomenon also exists from contact between identical tribo materials with the advancement of surface modification. However, a comparison of composite and identical homogeneous TEGs has yet to be reported. For this research, organic polymer membranes Polyamide-6 (PA6) and Polytetrafluoroethylene (PTFE) were evaluated. The membranes were cut into samples of varying dimensions to build three sets of TEGs for comparison. Two identical sets of four sampled TEGs were fabricated using the same membrane (i.e., PA6-PA6 and PTFE-PTFE); in contrast to a composite set of four sampled TEGs made from the two distinct membranes (i.e., PA6-PTFE). By repeatedly sampling the TEGs in sliding mode at a speed of 0.2 m/s and with a vertical force of 9.8 N an open circuit voltage (Voc) was generated and recorded. As a result, the Voc of the identical TEGs was compared to the Voc of the composite TEG in which the tribo materials are located at opposite ends of the triboelectric series. It was also observed that the Voc increased almost linear in relation to the surface area of the TEGs; thus, suggesting that the surface area of the TEG can influence significantly the Voc to a great extent. Graphical abstract 
PubDate: 2023-11-25
- Optimization of Sputtering Parameters and Their Effect on Structural and
Electrical Properties of CAAC-IGZO Thin-Film Transistors-
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Abstract: A c-axis aligned crystalline indium gallium zinc oxide (CAAC-IGZO) possesses unique properties beneficial for thin-film transistors (TFTs). In this study, we investigate the effect of oxygen ratio and radio frequency (RF) power on the structural, electrical, and operational characteristics of CAAC-IGZO thin films. Films were deposited on SiO2 substrates using an RF sputtering system equipped with a target containing In, Ga, Zn, and O with a composition ratio of 1:1:1:4. The effect of oxygen percentage on the structural characteristics was analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM). The oxygen percentage in the film was found to play a crucial role in forming the CAAC-IGZO and orientation of the thin films. With increasing O2 fraction, the (009)-preferred orientation of the films improved. X-ray absorption spectroscopy also validated the improved orientations of the CAAC-IGZO with high O2 concentrations up to 70%. In terms of TFT performance, however, the device with 3.3% oxygen exhibited the best performance with a saturation mobility of 10.9 cm2 V− 1 s− 1. TFT devices were prepared at a low oxygen fraction (10%) with different RF power inputs from 100 to 250 W, where the device prepared with highest power (250 W) showed the best performance. Graphical 
PubDate: 2023-11-23
- Surface Chemical Reactions During Atomic Layer Deposition of Zinc
Oxynitride (ZnON)-
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Abstract: Atomic layer deposition (ALD) is a promising technique for fabricating high-quality thin films. For improving the process conditions and material quality of ALD, understanding the surface chemical mechanisms at the molecular level is important as the entire ALD process is based on the reactions of precursors on the substrate surfaces. Zinc oxynitride (ZnON) is gaining significant research interest as a p-type semiconductor material. Although the ALD of ZnON can be performed by dosing H2O and NH3 as oxygen and nitrogen sources, respectively, the elemental ratio of O and N in the deposited film differs considerably from that in the gaseous sources. In this study, the surface reactions of ZnON ALD are analyzed employing density functional theory calculations. All the ALD surface reactions of ZnO and ZnN are facile and expected to occur rapidly. However, the substitution of a surface *NH2 by H2O to form *OH is preferred, whereas the inverse reaction is implausible. We propose that the differences in the reactivity could originate from the higher bond energy of Zn–O than that of Zn–N. Graphical 
PubDate: 2023-11-10
- Inkjet-Printed Flexible Ultrasensitive Chemiresistive Sensors for
Aggregation Pheromone of Flour Beetles-
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Abstract: This work reports the first demonstration that a chemoresistive sensor can be used to detect the aggregation pheromone of flour beetles. To prepare the sensing element of such a sensor, a novel functionalization method was developed to amplify amine groups on the surface of carbon nanotubes (CNTs). Unlike traditional amine-amplification approaches in which amplification efficiency is significantly reduced by self-crosslinking, the current amine amplification process was self-crosslinking-free due to the use of a home-made compound in which amine groups were protected by Boc (tert-butyloxycarbonyl) protecting groups and could be deprotected as needed. The inkjet ink formulated from the functionalized CNTs, together with an amine-rich compound and a commercial silver nanoparticle-based inkjet ink, was used to fabricate (via inkjet-printing and drop-casting) lightweight, flexible, and miniature-sized chemiresistive sensors for 4,8-dimethyldecanal (DMD), a compound known to be the aggregation pheromone of several species of flour beetles. A home-built gas sensing system, including a commercial gas generator, a DMD permeation tube with its emission rate certified, a data-acquisition system, and some home-developed LabVIEW-based programs, was utilized to perform the DMD sensing trials. The sensors showed ultra-high sensitivity to synthetic aggregation pheromone DMD, as indicated by their prompt and significant responses to 100 ppb DMD vapor. A mechanism for the sensitive sensing of DMD is proposed. Graphical 
PubDate: 2023-11-08
- An Ideal Two-Dimensional Porous B4O2 as Anode Material for Enhancing Ion
Storage Performance-
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Abstract: The utilization of two-dimensional porous materials as anodes in ion batteries has garnered significant interest within the field of clean energy because of their flexible architecture, high conductivity, rapid diffusion process and high specific ion capacity. Herein, we developed a new metal-free 2D porous compound, namely, B4O2. The stability of the B4O2 monolayer was verified through the ab-initio molecular dynamics simulations and phonon spectrum calculations. The results demonstrate that the adsorption of K, Na, and Li atoms onto the B4O2 monolayer surface is remarkably stable, with all three species exhibiting a shared diffusion path. Specifically, we found that the adsorption of K atoms on the B4O2 monolayer surpasses that of Na and Li atoms, and the diffusion of K atoms occurs at a faster rate than Na and Li atoms on the same monolayer surface. The maximum theoretical specific capacity of K+, Na+ and Li+ is calculated to be 626.1 mAh/g. In addition, the B4O2 monolayer retains good electronic conductivity and electron activity during the atomic adsorption processes. Based on our findings, the B4O2 monolayer exhibits significant potential as anode material for ion batteries. This study paves the way for a novel approach in designing new 2D porous materials specifically tailored for energy storage and conversion applications. Graphical 
PubDate: 2023-11-07
- Near-Ultraviolet Lateral Photovoltaic Effect of Epitaxial Nb:SrTiO3 Films
on Si Substrate Using TiN as a Buffer Layer-
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Abstract: In recent years, significant attention has been directed toward exploring heterojunctions based on perovskite materials for ultraviolet photodetectors. This study focuses on the fabrication of high-quality single-crystal Nb:SrTiO3 (NSTO) films on Si substrates, achieved through the utilization of a TiN thin film as a buffer layer. The investigation delves into the lateral photovoltaic effect exhibited by the film. Characterization using X-ray diffraction and high-resolution transmission electron microscopy confirms the exceptional quality of the NSTO film. Notably, the observed position sensitivity attains an impressive value of 43.9 mV mm−1. Analysis of the lateral photovoltaic effect reveals response and relaxation times of approximately 105.6 ns and 4.49 µs, respectively. Intriguingly, fitting results for the relaxation time indicate minimal defects within the NSTO/TiN/Si heterostructures. These findings underscore the significant potential of NSTO/TiN/Si heterojunctions, presenting a promising avenue for their widespread application in the realm of position change technology. Graphical 
PubDate: 2023-11-02
- Correction to: Where to go for the Development of High‑Performance H2
Storage Materials at Ambient Conditions'-
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PubDate: 2023-11-01
- Physical Effects of 2PACz Layers as Hole-Transport Material on the
Performance of Perovskite Solar Cell-
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Abstract: Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT: PSS) is widely used as a hole-transport layer (HTL) in perovskite solar cells (PSCs) with inverted (p-i-n) structures. However, problems associated with the corrosivity of PEDOT:PSS prevent the commercialization of such PSCs. To solve this problem, we fabricated inverted PSCs using [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) as HTL. We used a mixture of N-methyl-2-pyrrolidone and N, N-dimethylformamide in the perovskite precursor, which reduced the amount of the antisolvent chlorobenzene. We investigated the physical effects of the amount of antisolvent used. In addition, we suggest a method to improve the performance of inverted PSCs using 2PACz as the HTL, thereby achieving higher performance. Graphical 
PubDate: 2023-11-01
- Synthesis of CeO2 Nanoparticles Derived by Urea Condensation for Chemical
Mechanical Polishing-
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Abstract: The synthesis of CeO2 nanoparticles for CeO2 based slurry gains continuous emphasis on improving its performance in the chemical mechanical polishing of dielectric materials. Urea was selected to dominate the growth and morphology during the calcination process. Thermogravimetry experiments were used to analyze the the decomposition behavior. Particle morphology and size were analyzed. Crystalline phase information and surface valence were used to compare the differences in surface physical and chemical properties of ceria by different synthesis process. The CeO2 nanoparticles synthesized with urea were dispersed in water as slurry. The particle sizes of CeO2 were measured by dynamic light scattering. The Zeta potential of CeO2 dispersion were measured to show dispersing performance. The CeO2 nanoparticles synthesized with urea condensation show good monodisperse properties. The material removal rate of silicon oxide and surface quality after chemical mechanical polishing were selected to evaluate the chemical mechanical polishing performance. The CeO2 nanoparticles synthesized with urea condensation not only yielded better surface quality results than the commercial slurry but also showed a 153% (pH = 4) and 100% (pH = 10) increase in the material removal rate of silicon oxide compared to commercial. Graphical 
PubDate: 2023-11-01
- Enhancement in Power Factor of Al-Doped Cu2Se Thermoelectric Compound
Prepared by Combustion Synthesis via Spark Plasma Sintering Technique-
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Abstract: An attempt was made to dope the aluminium in the copper site of the Cu2Se compound via combustion synthesis during spark plasma sintering. A series of Cu2−xAlxSe (x = 0, 0.01, 0.02, 0.03) materials were prepared by combustion synthesis during spark plasma sintering and short annealing. The X-Ray diffraction reports reveal that the prepared materials like Cu2Se consist of α—Cu2Se phase, Cu1.99Al0.01Se, Cu1.98Al0.02Se consist of a mixture of α—Cu2Se and β—Cu2Se phases, and Cu1.97Al0.03Se consist of β—Cu2Se phase. The doping of aluminium enhances the electrical conductivity and power factor value. Furthermore, Al-doping causes the Al–Cu secondary phase formation and aluminium cluster, which also significantly affect the electrical properties of the compounds. The sample Cu1.98Al0.02Se exhibits a power factor of 13.73 at 700 °C, which is 23.5% higher than the pure Cu2Se sample prepared. Graphical 
PubDate: 2023-11-01
- The Influence of Nano- and Micron-size of MXene Flakes on the
Electrochemical Performance-
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Abstract: MXene, as a new type of two-dimensional material, has attracted much interest since it was discovered in 2011. However, only few articles discussed the effect of MXene flake size on its electrochemical performance. Here, a sand milling way is explored to produce nano-size MXene and the MILD method is used to prepare micron-size MXene (1 μm) as a comparison. Meanwhile, a mask-assisted interdigital micro-supercapacitors is prepared to explore the dependence of the electrochemical properties of MXene on their flake size. We show that nano-size MXene (200 nm) has a higher ionic conductivity as compared to normal micron-size MXene (1 μm). On the contrary, the larger flake size has higher electrical conductivities. As a result, the capacitance of micron-size MXene is better than nano-size MXene (200 nm) because the electrical conductivities are dominant. This research is helpful for further understanding of the influence of MXene flake size on its electrochemical performance. Graphical abstract 
PubDate: 2023-11-01
- Thermal Management Performance of Epoxy Composites with Boron Nitride and
Boron Phosphide Hybrid Fillers-
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Abstract: Thermal interface materials with high thermal conductivity are the best choice to solve the current overheating problem of electronic devices, and the choice of thermal conductive filler is a key factor affecting the performance of thermal interface composites. Hexagonal boron nitride sheet is considered to be ideal thermal conductive filler, but the thermal conductive effect of single filler is still insufficient to meet actual needs. Here, a new type of hybrid filler mixed with boron nitride sheet and boron phosphide particles is used to prepare epoxy based composites. When the filler volume fraction is 40%, the thermal conductivity of composites reaches 3.18 W m−1 K−1. Under the same content, the thermal conductivity of the composites with mixed fillers outperforms those with boron nitride sheet alone. At the same time, the composite material shows high breakdown strength of 46 kV mm−1. This work provides a new way to prepare thermal interface materials with high thermal conductivity for modern electronic packaging. Graphical 
PubDate: 2023-11-01
- Effects of Bath Composition and Current Density on the Electrodeposition
Behavior of Fe–Ni Invar Alloy-
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Abstract: Fe–Ni invar alloy (Fe 64–Ni 36 wt%) has a very low coefficient of thermal expansion (CTE) than any other metals. For this reason, it has been used as fine metal mask (FMM) in RGB patterning of OLED manufacture process. However, as the resolution of OLED display is getting higher, the thickness of FMM is getting thinner and then the conventional extruded invar sheet cannot be used directly. The electrodeposition of invar can be the alternative for fabrication of thin FMM. In this study, the Fe–Ni alloy were electrodeposited varying bath compositions and current density. Also, the effects of ferric ion (Fe3+), produced during electrodeposition on inert anode, on the behavior of deposition were investigated. Finally, the Fe–Ni alloy with 36–40 wt% Ni were obtained at 50 mA/cm2 in 0.30 M Fe2+ bath. The back side and front side composition of the deposits were analyzed to evaluate the composition uniformity of the Fe–Ni alloys. Generally, the Fe content of back side of the deposits were higher than that of front side. Graphical 
PubDate: 2023-11-01
- Effect of Surface Termination on Carrier Dynamics of Metal Halide
Perovskites: Ab Initio Quantum Dynamics Study-
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Abstract: Metal halide perovskites (MHPs) have attracted considerable attentions as promising candidates for next-generation optoelectronic devices, such as light-emitting diode (LED), owing to their outstanding photophysical properties. Nanostructuring is considered an essential approach to facilitate the bright emission of MHPs, which entails an increase in the surface domain that can directly affect the carrier dynamics. However, a comprehensive understanding of the surface termination effect on the photodynamic properties of MHPs is still lacking. Herein, we systematically investigate the effect of surface termination on the carrier recombination dynamics of CsPbBr3 using ab-initio non-adiabatic molecular dynamics simulations. We found separate localizations of electron and hole carriers in the vicinity of the more and less coordinated inorganic polyhedral, respectively, which can be explained by the energy level changes associated with the modifications in Pb–Br bond lengths and their anharmonicity. This leads to the spatial separation of charge carriers, which retards the radiative kinetics more than the non-radiative one, reducing the photoluminescence quantum yield (PLQY). We further found that the homogenous linewidth is broadened upon introduction of surface terminations. Thus, our study suggests a possible LED-performance degradation mechanism due to surface termination, and thereby proposes guidelines for enhancing the light-emission properties of nanostructured MHPs. Graphical 
PubDate: 2023-11-01
- Green Synthesis of Ce Doped Cs3MnBr5 for Highly Stable Violet Light
Emitting Diodes-
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Abstract: Over the past few decades, wide-bandgap semiconductor materials have been extensively explored for short-wavelength light-emitting diode (LED) owing to their rich technological applications spanning from phototherapy, sensors, and healthcare, to the indoor plantation. However, to date, few papers have reported violet-emitting (< 435 nm) perovskite materials and LEDs. Despite the tunable bandgap property, perovskite researchers are still lagging to achieve efficient violet emitting material. The presence of toxic lead, environment stability, complex synthesis, and achieving a large bandgap emitter have put a constraint on the development of violet perovskite LEDs. To address the abovementioned issues, herein we report a simple water-assisted synthesis of lead-free wide-bandgap perovskite with bright violet emission. No use of other solvent during synthesis makes our process very simple, cost-effective, and eco-friendly. As synthesized Ce doped Cs3MnBr5 shows a visible blind absorption with an effective optical bandgap of 3.12 eV. Introduction of Ce in Cs3MnBr5 lattice demonstrate dual violet emission peaks at 387 and 419 nm. Our synthesized Cs3MnBr5:Ce also shows a good environment stability with narrow full-width half maxima (FWHM). We achieve the violet light with standard chromaticity coordinates of (0.18044, 0.02034) which makes Cs3MnBr5:Ce a promising candidate for stable violet perovskite LEDs. Graphical 
PubDate: 2023-11-01
- Compressive Sinter Bonding in Air Between Cu Finishes Using Paste
Containing Composite Ag2O-Cu Filler-
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Abstract: A Ag2O-Cu composite filler was adopted as a sintering material between Cu finishes under compression to achieve the high-speed bonding of dies in an air atmosphere via a cost-effective paste and finish process. The commercial Cu particles had an average size of 2 μm, and the synthesized Ag2O particles were in the submicrometer range with an average size of 210 nm. The Ag2O particles in the paste started decomposing at ∼150 °C, and the liquid-type reductant in the paste effectively reduced the oxide layers on the Cu particles as well as the upper and lower Cu finishes during bonding. Therefore, the in situ-generated active Ag and fresh Cu surfaces enabled significantly rapid sinter bonding under 5 MPa compression. Only 30 s of bonding at 300 °C was required to achieve an excellent shear strength of 27.8 MPa in the created bond-line, while 90 s of bonding produced a near-full-density structure with a strength of 41.9 MPa despite solid-state sintering when the 3:7 (Cu particles:Ag2O particles) mixing ratio was used. Well-dispersed Ag2O particles did not create a non-sintered interface or form large voids upon outgassing during decomposition. The out-diffused Cu was reoxidized after sintering with Ag, forming irregularly dispersed Cu2O shells that remained in the microstructure of the full-density bond-line. Graphical 
PubDate: 2023-11-01
- Enhanced Lithium Storage Properties of High Sulfur Doped Hard Carbon
Derived from Thiophene-Containing Conjugated Microporous Polymer-
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Abstract: The development of hard carbon with high capacity and long cycling stability is a significant issue for lithium ion batteries. Herein, thiophene-containing conjugated microporous polymer (SCMP) was synthesized using 1,3,5-triethynylbenzene 2,5-dibromothiophene by Sonogashira-Hagihara crosscoupling reactions. Then, high sulfur doped hard carbon (SHC) and KOH activated SHC (SHC-K) are prepared by direct carbonization and KOH-assisted carbonization of SCMP, respectively. Both samples were then investigated by SEM, elemental analysis, FTIR, XPS and Nitrogen adsorption/desorption. Taking advantages of sulfur content and abundant porosity, SHC-K delivers a first charge specific capacity of 842.2 mAh g−1 at 0.1 A g−1 and a specific charge capacity of 565.9 mAh g−1 after 500 cycles at 0.6 A g−1. Graphical 
PubDate: 2023-11-01
- Contact and Interface Engineering of MoS2-Based Photodetectors Using
Electron-Beam Irradiation-
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Abstract: The effect of electron-beam irradiation (EBI) on MoS2-based photodetectors with various electrode structures was investigated to improve the electrical and photoelectrical properties. The MoS2 films were deposited at room temperature by RF magnetron sputtering and subsequently transformed into a two-dimensional layered structure by EBI treatment with the electron energy of 3 kV for 1 min. The electrical resistance and photoelectrical properties, such as photocurrent and photoresponsivity, of MoS2 films were examined with patterned Au/Ti electrodes as a top contact (TC) and a bottom contact structure. In addition, the interfacial effect of high-k dielectric materials of thin HfO2 film between MoS2 and the SiO2/Si substrate was investigated to enhance the photoelectrical property. The MoS2 photodetectors fabricated by the EBI before TC formation on HfO2 exhibited the highest photoresponsivity of 11.88 mA/W, which was an increase of 6500% from the EBI before TC structure on SiO2. We believe that this work contributes to the improvement of contact and interface properties of MoS2-based photodetectors readily and quickly compared with conventional high-temperature thermal treatment. Graphical 
PubDate: 2023-11-01
- Electron-Beam-Induced Formation of Oxygen Vacancies in Epitaxial LaCoO3
Thin Films-
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Abstract: The formation of oxygen vacancies in heteroepitaxial LaCoO3 thin films deposited on different substrates was investigated by using electron beam irradiation in atomic-scale scanning transmission electron microscopy (STEM). As the electron beam irradiation intensified, distinctive dark stripe patterns were identified in high-angle annular dark-field STEM images, demonstrating the formation and subsequent ordering of oxygen vacancies. A comprehensive quantitative analysis of the lattice parameter changes verified the significant expansion of unit cells associated with the presence of oxygen vacancies. In particular, a uniform distribution of these expanded unit cells was observed in the films under large tensile strain. These experimental findings emphasize the significant role of strain in generating oxygen vacancies in perovskite oxide materials. Graphical 
PubDate: 2023-10-30
- Relationship Between Electrical Conductivity and Supercapacitor Properties
of Co3O4 Nanofibers Fabricated by Electrospinning-
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Abstract: Co3O4 with a spinel structure has been utilized as supercapacitor materials due to their active surface sites, strong absorption capacity, excellent electrochemical activity, and stability. In this study, we tried to explore the optimized electrospinning conditions, including heat-treatment temperature for Co3O4 nanofiber fabrication for supercapacitor applications. The X-ray diffraction patterns of Co3O4 nanofibers annealed at 600 and 800 ºC showed a cubic spinel crystal structure without a secondary phase, but CoO was found in the specimens annealed at 400 ºC. From the XPS curve fitting, Co3+ increased in the Co3+/Co2+ ratio with increasing heat-treatment temperature. The electrical conductivity of the Co3O4 nanofibers heated at 400, 600, and 800 ºC is 7.53 × 10−3, 1.12 × 10−2, and 6.26 × 10−3 Ω−1 cm−1, respectively. The Co3O4 nanofibers heat treated at 600 ºC showed the highest conductivity value, and the conduction mechanism was polaron hopping between Co3+ and Co2+. The supercapacitor properties of Co3O4 nanofibers are evaluated by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance measurement using a three-electrode system in a 3 M KOH electrolyte. The GCD tests showed that the Co3O4 nanofibers heated at 600 ºC had the highest specific capacitance of 579.66 F/g. From the electrochemical impedance measurements, the charge transfer resistance (Rct) of calcined Co3O4 nanofibers at 600 ºC showed the lowest value of 1.27 Ω. Also, the Co3O4 nanofiber exhibits excellent cycle stability with capacitance retention over 99% until 1000 cycles at a current density of 2 A/g. Therefore, the excellent supercapacitor performance of Co3O4 nanofibers annealed at 600 ºC is due to its nanofiber structure without a secondary phase providing a larger surface area and charge transfer. Graphical 
PubDate: 2023-10-24
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