Journal of Materials Science: Materials in Electronics最新文献

Metal oxides have demonstrated significant potential in water purification applications with the recent advancements in photocatalytic technologies. In this study, a ZnO/CuO nanocomposite was synthesized via a facile chemical co-precipitation method by successfully integrating zinc oxide and copper oxide semiconductors. The structural, compositional, and optical properties of pristine ZnO and the ZnO/CuO composite were comprehensively characterized. Under Xe light irradiation, the ZnO/CuO nanocomposite has exhibited superior photocatalytic performance, achieving substantial degradation of norfloxacin (NOR) and methyl orange (MO) within 120 min under optimized conditions. The degradation rates for 10 ppm concentrations of NOR and MO were calculated as k = 1.085 × 10^-2 min^-1 (99% degradation) and k = 3.849 × 10^-2 min^-1 (70% degradation), respectively. Kinetic analyses revealed that the degradation has followed pseudo-first-order kinetics, and observed to be consistent with the Langmuir–Hinshelwood model. Scavenger experiments have identified h⁺, O₂^•−, and ^•OH radicals as key species driving the photocatalytic degradation of MO, while O₂^•− primarily governed NOR degradation. In addition, the ZnO/CuO composite has maintained high photocatalytic efficiency after ten reuse cycles. These findings suggest that the ZnO/CuO nanocomposite is a promising candidate for the photocatalytic treatment of water contaminated with NOR and MO pollutants.

The Cu₂MnSnS₄ (CMTS) film was prepared using the hydrothermal technique. The CMTS thin film was analyzed by the techniques of Ultraviolet–Visible (UV–Vis) spectroscopy, energy-dispersive X-ray (EDX or EDS), and scanning electron microscopy (SEM). To fabricate Al/Cu₂MnSnS₄ (CMTS)/p-Si/Al diode, the CMTS film was covered on p-Si wafer by a sol–gel spin-coating technique and the metallic contacts were prepared on film with pure aluminum. The current–voltage (I–V) properties of Al/Cu₂MnSnS₄ (CMTS)/p-Si/Al device were analyzed under dark and distinct illumination intensities (20, 40, 60, 80, and 100 mW/cm²). It was determined that the effect of light created a higher current compared to the dark current, and the reverse bias current increased approximately 80 times depending on the illumination intensity, which confirmed that the produced diode exhibited photoconductive behavior. The ideality factor (barrier height) values obtained as a result of the measurements performed in the dark and 100 mW/cm² light intensity conditions of the produced device were found to be 3.85 (0.68 eV) and 4.54 (0.67 eV), respectively. Transient current measurements also supported this situation and also showed that the device could be enhanced as a photo-capacitor. In addition to these measurements, the effect of frequency and applied voltage on capacitance properties was investigated. The acquired results showed that both conductivity and capacitance were under a strong influence in reverse biasing. Considering all the results together, it has been shown that the used Cu₂MnSnS₄ (CMTS) material and the produced device are a strong candidate to be used in photovoltaic technology.

The bonding properties of solderable anisotropic polymer composites (SAPCs) containing only low-melting-point alloy (LMPA) fillers need improvement. In this study, a new composite containing LMPA and high-melting-point alloy (HMPA) fillers, named LH-SAPC, was proposed, and the establishment of the conduction path and bonding properties of LH-SAPC were investigated for different LMPA/HMPA mixing proportions. Six types of LH-SAPC filled with different LMPA/HMPA mixing proportions (100:0, 80:20, 50:50, 20:80, 10:90, and 0:100) were formulated, and bonding tests were performed using the quad flat package. The LH-SAPCs containing less than 50 vol% HMPA within the LMPA/HMPA filler formed a proper and broad conduction path through of the excellent inner flowage of molten fillers within the polymer composite maintaining a low-viscosity condition, coalescence behavior between adjacent fillers, and a wetting behavior for the metallization. In addition, the mechanical bonding properties of the LH-SAPC joints improved with increasing HMPA content owing to the precipitation hardening and dispersion strengthening effects of the finely distributed Bi-rich phase and intermetallic compound particles within the conduction path and grain refinement. In contrast, as the HMPA content was excessive within the LH-SAPC, a poor conduction path was established because of the fluidity deterioration of the molten HMPA, which was attributed to the immoderate curing of the polymer composite; accordingly, the mechanical properties of the LH-SAPC joint degraded.

We report the insertion of a new intermediate layer, a multi-layered graphitic carbon (MLGC), at Mo/CZTS interface and its impact on the structural and morphological characteristics of the back interface and absorber. MLGC was synthesized directly on Mo-coated SLG under a gas mixture flow of H₂/CH₄ at 550 °C via PECVD for 3 and 5 h. CZTS precursors were prepared on SLG/Mo and MLGC-coated SLG/Mo in a hybrid physical vapor deposition system, including evaporation and sputtering techniques, then subjected to sulfurization at 550 °C. The sheet resistance of back contact, microstructural parameters of the absorbers, the distributions of C and constituent elements were investigated. The diffraction peaks of the hexagonal Mo₂C indicated the reaction between the C and Mo before the MLGC’s growth. Raman analysis confirmed the formation of the MLGC during the long deposition time after the Mo₂C formation. With the addition of MLGC, the sheet resistance of the back contact decreased from 2 to 0.5 Ω/sq, and the crystallite size of the absorbers improved. Raman spectra from the interface exhibited that MoS₂ peaks’ intensities significantly reduced with increasing the growth time. This implied that the 5 h-deposited MLGC was more effective in blocking the reaction between Mo and S. The absorbers with the MLGC had more uniform surface morphologies, densely packed grains, and fewer secondary phases. FIB analysis revealed the separation of the absorber with the 5 h-deposited MLGC into two parts due to C impurity. More C diffusion into the absorber for this sample was confirmed by SIMS.

The present study investigates the behavior of Sn whisker growth on Sn-0.7Cu-0.05Ni solder joints during thermal cycling conducted for 1500 cycles at temperature of − 40 (+ 0/− 10) °C and + 85 (+ 10/− 0) °C through industry standard practices JESD22-A121A established by the Joint Electron Device Engineering Council (JEDEC). Results determine that the growth rate of Sn whisker on the Sn-0.7Cu-0.05Ni solder joint was slower than the Sn-0.7Cu solder joint and consequently show that the 0.05% addition of Ni is able to suppress the growth of Sn whisker during thermal cycling. Furthermore, the stabilization of hexagonal η-Cu₆Sn₅ of (Cu,Ni)₆Sn₅ IMC interfacial layer in Sn-0.7Cu-0.05Ni solder joints significantly contributes to a lower coefficient of thermal expansion (CTE) compared to Cu₆Sn₅ IMC interfacial layer, thereby reducing thermal mismatch stress for Sn whisker growth on the Sn0.7Cu0.05Ni solder joint. The implications of this study are substantial for effective approach to mitigate Sn whiskers growth through consistent inspection protocols and adherence to industry standard practices.

In this work, indium silicon oxide (ISO) active channel layers were deposited at room temperature using radio frequency (RF) magnetron sputtering. Aluminium oxide (Al₂O₃), deposited via atomic layer deposition (ALD) over a p-type crystalline (100) silicon (p-Si) substrate, served as the dielectric and gate electrode respectively, for the construction of thin-film transistors (TFTs). A molybdenum (Mo) metal contact was deposited as the source and drain using RF sputtering at room temperature. The maskless photolithography process was employed for patterning the active channel layer and source/drain contacts with various channel widths (W) and lengths (L). The average capacitance per unit area (C_i) and the dielectric constant (κ) of the Mo/Al₂O₃/p-Si metal–insulator-semiconductor (MIS) structure were calculated to be 56.05 nF/cm² and 6.33, respectively. The ISO TFT, post-annealed at 200 °C, with a length (L) of 100 µm and a width (W) of 200 µm, exhibited a saturation mobility (µ_sat) of 20.24 cm²/V·s, an on–off drain current ratio (I_ON/I_OFF) of 1 × 10⁹, a turn-on voltage (V_ON) of − 2 V, and a sub-threshold swing (SS) of 0.52 V/dec.

An efficient SiO₂:Ce nanophosphor has been synthesized by fuel assisted combustion method, later annealed in a reducing atmosphere to achieve phase stability and to monitor the effect on its CL properties. The formation of low–quartz’s structure is reported by using XRD analysis. The spherical porous nanosized morphology is revealed by HRTEM analysis. The porous nanophosphor is excited by electron beam exposure at pressure of 10^{− 6} Torr with different electric power (i.e. voltage of 1−5 keV and current of 3−18 µA). A stable cyan (blue−green) emission has been recorded regardless of change in applied electrical power. The minor increase in the CL intensity is also noted for annealed nanophosphor. In the RGB color model, used to create all the colours on a computer or television display, cyan is made by mixing equal amounts of green and blue light. An efficient and stable CL broadband emission extending from 300 to 600 nm maximum at 440−525 nm is recorded makes the SiO₂:Ce porous nanophosphor a suitable candidate to fulfil the cyan emission gap of the Field emission displays (FEDs).

Direct absorption solar collectors (DASCs) are a new generation of collectors that using nanofluids for directly converting solar radiation into thermal energy, which exist inevitable drawbacks such as unstable working fluid, complex preparation process, high cost etc. A simple, non-toxic, environmentally benign nanofluid with high photothermal conversion efficiency and high stability is requirable for DASCs. In this work, a novel deep eutectic solvent composed of glycerol and betaine is used as working fluids, which exhibit excellent stability and repeatable performance at the working temperature. The highest photothermal conversion efficiency can reach 96.59% for 50 ppm nanofluids, which is 39.57% higher than the pure working fluids. An outdoor experiment is conducted utilizing a heat exchanger to extract warm water (50 ℃) from the nanofluids under flowing conditions, which can fully meet people's daily hot water needs. This study paves a new avenue for seeking for stable and environmentally benign nanofluids in the solar thermal conversion technique.

The traditional melt quenching method is used to synthesize the various trivalent samarium ion concentrations doped Bismuth-Antimony-Fluoroborate glasses (BiSFB). Physical, structural, spectroscopic, and electrical properties of the prepared glasses are examined. X-ray diffraction (XRD) and FTIR spectra were used to analyze the amorphous nature and functional groups present in the prepared glasses. Judd–Ofelt (JO) intensity parameters Ω₂, Ω₄, and Ω₆ follow the trend Ω₄ > Ω₆ > Ω₂ for all concentrations. Radiative parameters for the fluorescent levels of Sm³⁺ ions in BiSFB glasses are calculated using JO parameters. The PL spectra show three emission bands at 562, 599, and 646 nm. The effective bandwidth and stimulated emission cross sections have relatively high values for 0.5 mol% concentration of Sm³⁺ ion for ⁴G_5/2 → ⁶H_7/2 transition among all the prepared glasses. Relatively high quantum efficiency calculated via decay curves shows 0.5 mol% concentration of Sm³⁺ ion to be optimum for solid-state lighting and optoelectronic devices. CIE color coordinates also confirm the red and orange-red emission for the prepared glasses. The dielectric properties (dielectric constant (ɛ′), dielectric loss (ɛ″)), Nyquist plot, electrical ac conductivity (σ_ac), and dc conductivity of these glasses with variation in frequency have also been studied at the ambient temperature. With an increase in applied frequency, particularly in the high-frequency region, the ac and dc conductivities are increased. Analysis of optical and electrical properties suggests the application of present glasses in optoelectronic devices and solid-state ionic materials.

TiO₂ has been widely used in photocatalytic water splitting, but its wide band gap and easy recombination carrier limit its further application. In this work, highly ordered TiO₂ nanotube arrays (TiO₂ NBs) were prepared by anodic oxidation, and more oxygen vacancies were provided by local amorphous. The increase of oxygen vacancy improves the carrier separation efficiency, and the array structure achieves faster electron transport. In addition, WO₃ semiconductor was coupled with TiO₂ to construct heterojunction, expand the range of light absorption, and enhance the electron–hole pair separation efficiency. In addition, by introducing co-catalyst CoPi, the active site of the reaction was increased, and the catalytic reaction efficiency was improved kinetically. The results show that the photocurrent of CoPi/WO₃/TiO₂ NBs is 10.2 μA/cm², which is 1.68 times that of TiO₂ NBs.