Journal of Electronic Materials最新文献

The potential-induced degradation (PID) performance is of high significance for photovoltaic (PV) modules. In accordance with the IEC 61215-2: 2021 standard, we analyzed the factors that affect the measurement of PID performance, including the effects of a light soak of the p-type gallium (Ga)-doped silicon mono-facial PV modules, the resistivity of the water used for humidification of the environmental chamber, and the relative humidity of the chamber. We also examined the change of the modules’ anti-PID performance under the erosion by NaCl solution and by higher humidity combined with NaCl solution. The results show that a light soak pre-treatment before the PID test of the module leads to a difference of 0.02% in average power loss. The influence of humidifying water with different resistivities used in the environmental chamber on the PID test is negligible. An increase in humidity substantially reduces the anti-PID performance of the module. When the EVA film thickness was reduced from 0.65 mm to 0.55 mm, the power loss increased from 2.25% to 3.96% after the PID test. In addition, NaCl on the backsheet of the module could accelerate the PID effect under applied electric field conditions, resulting in the formation of localized darkening area observed under electroluminescence (EL) image. Finally, after the PID test in the presence of higher humidity and NaCl solution, the average power loss of the modules amounted to 10.80%, while it was 1.29% for the modules after the standard PID test. Therefore, it is vital to improve the anti-PID performance of mono-facial PV modules in a high relative humidity and salt-mist environment.

Yttrium iron garnet (Y₃Fe₅O₁₂, YIG) ferrite has excellent magnetic properties that are suitable for microwave communication devices. In the present research, Ca-Zr co-substituted Y_1.83−xBi_1.17Ca_xFe_5−xZr_xO₁₂ (YBiIG, x = 0.00–0.15 with a step of 0.05) ferrites were prepared by a solid-state reaction method to enhance microwave magnetic and dielectric properties. The phase formation, microstructure, and magnetic and dielectric properties of the materials were investigated by x-ray diffraction, scanning electron microscopy, impedance analyzer, vibrating sample magnetometer (VSM), and ferromagnetic resonance (FMR) linewidth. The results showed that Ca²⁺-Zr⁴⁺ ions did not change the phase formation of the ferrites and enhanced the magnetic permeability (mu^{{prime }}) ((mu^{{prime }}) = 24.10 at 10 MHz, x = 0.15) and dielectric constant ((varepsilon^{{prime }}) = 24.55 at 10 MHz, x = 0.15). Meanwhile, the specific saturation magnetization (σ_s) increased from 20.26 emu/g to 22.79 emu/g with the increase of Ca-Zr substitution, and the FMR linewidth (ΔH) decreased from 406.34 Oe to 339.60 Oe. The work showed that the high dielectric constant exhibited by Ca-Zr-substituted YBiIG ferrite materials has potential application value in high-frequency microwave device applications, such as circulators, isolators, phase shifters, and other microwave components.

β-Gallium oxide has well-studied electrical characteristics but relatively less explored optical as well as magnetic properties. In this work, pure and Ni-doped β-Ga₂O₃ polycrystalline powders were prepared using a hydrothermal method to study the structural, optical, and magnetic properties at various concentrations of Ni at 1 M%, 3 M%, 5 M%, and 7 M%. XRD analysis confirmed the formation of monoclinic β-Ga₂O₃ up to Ni 1 M% doping. The formation of additional peaks was observed exclusively for the samples doped with Ni from 3 M% to 7 M%. These additional peaks belong to NiGa₂O₄ that has an inverse spinel structure. The reflectance studies using UV–Vis diffuse reflectance spectroscopy shows a reduction in bandgap from approximately 4.7 eV to 4.1 eV with the addition of the dopant. The emission peaks observed from photoluminescence studies shows UV, blue, and green emissions with varying intensity. Room-temperature magnetic studies performed using a vibrating sample magnetometer showed a transition from the diamagnetic state of the pure sample to the antiferromagnetic state with increasing Ni concentration in the doped samples. The diamagnetic properties of β-Ga₂O₃ makes it ineffective in spintronic applications. From the present work, the improved magnetism due to Ni doping coupled with the optical properties suggests that nickel-doped gallium oxide can be used as an optical magnetic bifunctional material.

This paper investigates the impacts of epoxy material viscosity and different gold wire configurations on the total maximum deformation, maximum von Mises stress, and maximum equivalent elastic strain on the light-emitting diode (LED) encapsulation process. The simulation of the LED encapsulation process employed the Volume of Fluid (VOF), Fluid–Structure Interaction (FSI), and System Coupling methods within ANSYS software. The simulation results for an epoxy molding compound (EMC) with viscosity of 0.448 kg/m·s were validated by an experiment. A grid independence test was run to determine the minimum mesh refinement required for the simulation. The results revealed that the final fluid profile of the EMC at 0.448 kg/m·s conformed more closely to the experimental results than the other epoxies. The overall best performance of the wire configuration to the EMC on the LED encapsulation process, in descending order, was the square-loop, triangle-loop, S-loop, Q-loop, and M-loop. This study contributes to understanding the effects of epoxy materials and various gold wire configurations on key mechanical parameters in the LED encapsulation process, hence guiding LED manufacturers in selecting optimal epoxy materials and wire configurations to improve process reliability and performance.

In ordered to understand the electronic structure, structural phase stability, magnetic properties, and Fermi surface studies of the 122 type of SrFe₂X₂, where (X = P, As, Sb) were investigated. For this purpose, the plane wave self-consistent method was used. Using the Brich–Murnaghan equation, their electronic structure and magnetic ordering were also investigated. It was understood that, under pressure, the compound SrFe₂As₂ undergoes a structural phase change from the tetragonal phase into the collapsed tetragonal phase. Further, due to their larger lattice constants, antimonides with larger local iron magnetic moment exhibit an enhanced Hund's rule coupling. Furthermore, smaller intra-atomic exchange coupling and significantly smaller lattice constants may be the cause of the extremely small local Fe moment for phosphates. The analysis of the valence charge density in the collapsed tetragonal phase demonstrates that the interactions between As atoms are more pronounced when compressed along the c-axis. The strength of this interaction is primarily governed by the Fe-As chemical bonding. The collapsed tetragonal phase of SrFe₂As₂ compounds, as observed in Fermi surface studies, indicates the absence of nesting of Fermi surfaces. It is clear that, from the studies, the tetragonal phase of Fermi surface nesting resulted in the long-range magnetic order, leading to the presence of superconductivity.

In this work, thin films of CuO doped with 3% SnCl₂ (0.97 g CuO-0.03 g SnCl₂) were deposited on glass substrates using a sol–gel spin coating technique. The deposited thin films were annealed in a muffle furnace at 400°C for 2 h. UV–visible spectroscopy, a two-probe setup, and x-ray diffraction were utilized to analyze the optical, electrical, and structural properties, respectively. The optical bandgap of the doped films was identified within the range of 3.7–3.83 eV. Electrical investigation performed by the two-probe setup revealed that the prepared samples were ohmic in nature. It was found that the resistivity of the samples varied from 11.86 Ω·m to 6.04 Ω·m as the thickness of films increased from 165 nm to 570 nm. The gas-sensing properties of the prepared films were assessed at different operational temperatures and for varying concentrations of hydrogen sulfide gas. From the obtained data, it was observed that SnCl₂-doped CuO thin films show excellent response toward H₂S gas at room temperature.

Fluorescence intensity ratio (FIR) technology is compulsorily needed in non-contact rare-earth luminescent temperature sensors. Here, we present Er/Yb:Y₃Al₅O₁₂ phosphors synthesized via a high-temperature solid-state reaction method. The crystal structure, microstructure, up-conversion luminescence, and energy transfer between the two ions have been comprehensively analyzed. Under 980-nm excitation, the samples exhibited four distinct transition bands at 475 nm, 525 nm, 546 nm, and 664 nm. The quantum efficiency reached 12.14%. Utilizing the thermally coupled level of I₅₂₅/I₅₄₆ as a basis for analysis yields a maximum relative sensitivity of 1.05% K⁻¹. We observed that the spectral color coordinates varied linearly with temperature within a specific range, suggesting its potential application as a means of temperature measurement. Furthermore, employing the non-thermally coupled levels of I₅₄₆/I₄₇₅ for temperature measurement results in an impressive maximum absolute sensitivity of 8.05% K⁻¹, nearly 24 times higher than that achieved through thermally coupled levels alone. The temperature resolution of the synthetic material is basically less than 0.3 K with high thermal stability. Therefore, Er/Yb:Y₃Al₅O₁₂ phosphors hold promise as viable candidates for components in temperature-sensor applications.

The rapid development of Internet of Things (IoT) technology is driving a transformation in the healthcare sector. This paradigm change provides new opportunities for real-time, ongoing physical parameter monitoring, particularly in remote situations, providing an ideal setting for research and development. IoT device deployment has become widespread, enabling the growth of an automated data exchange ecosystem. However, our capacity to carry out remote monitoring has been constrained by our past dependence on specialized electronic equipment for assessing vital signs such as heart rate (beats per minute [BPM]) and oxygen saturation (SpO2). To address this issue, we developed an innovative technology that makes use of internet connectivity to allow for remote vital sign measurement and monitoring. The main focus of this article is the use of IoT technology to measure and track vital physiological indicators, notably heart rate and oxygen saturation, regardless of a person’s location. In addition, our study aims to create a system that can send out real-time notifications in the event of serious medical emergencies, increasing the likelihood that life-saving actions can be taken in a timely manner.

A theoretical prediction of the contribution to the thermo-electromotive force (thermo-EMF) of a thermocouple due to the minority charge carriers in both legs is presented. This prediction is made on the assumption that, at any time, the electrical conductivity of the majority charge carriers (sigma _M) remains very large compared to the electrical conductivity of the minority carriers (sigma _m) ((sigma _Mgg sigma _m)). The expression has also been analyzed in order to find strategies to reduce its negative impact on the thermo-EMF of the thermocouple. Finally, calculations were carried out in the case of the thermocouple made of silicon thermoelements. The results show that the presence of minority carriers in the thermocouple legs can either positively or negatively affect the generated thermo-EMF. Whenever the contribution is negative, its magnitude may be reduced by widening the bandgap of the N-type leg and/or narrowing that of the p-type leg, adjusting the length of the legs, or intensifying recombinations on the surfaces of the P-type leg

The existence of a variety of two-dimensional (2D) carbon allotropes with different carbon frameworks has provided an unprecedented platform to explore novel properties and potential applications beyond graphene. In this work, the strain effects on the structural, electronic, and thermal transport properties of the γ-graphyne and twin graphene sheets have been systematically clarified through first-principles calculations. Regardless of the geometrical similarities of the two considered 2D carbon allotropes, our results indicate that the acetylenic linkages in the γ-graphyne and the AA-stacked aromatic rings in the twin graphene are capable of resulting in the notable deviations in their electronic and thermal transport properties, as well as the strain-dependent behaviors. Both of the two sheets possess an intrinsic semiconducting nature with a tunable direct bandgap that depends on the biaxial strains. The thermal conductivity of the γ-graphyne is significantly suppressed compared to the twin graphene counterpart. Moreover, the heat transfer of the two sheets can be further enhanced by the tensile strains, and a dramatic increase can be obtained in the strained γ-graphyne sheet. Thus, the effectively tunable electronic and thermal transport properties revealed in this work imply the great potential of the two 2D carbon allotropes, and the comparative study also uncovers the structural effect of the carbon networks on their novel properties and strain responses.