Journal of Electronic Materials最新文献

Nanotechnology is a burgeoning modern technology due to the remarkable properties of nanoparticles. However, the escalating use of toxic reagents during the chemical synthesis of nanoparticles has become a major concern for environmental safety and human and animal health. Regarding this problem, the notion of integrating nanotechnology with green synthesis is increasingly attracting the attention of researchers. This particular study aims at the green synthesis of copper sulphide (CuS) nanoparticles S1, S2, and S3 utilizing the leaf extracts of Azadirachta indica (neem), Syzygium cumini (jamun), and Cascabela thevetia (kaner), respectively. The prepared leaf extract of neem is rich in quercetin, whereas extracts of jamun and kaner leaves contain gallic acid, which serves as a reducing agent during the formation of nanoparticles. The prominent and sharp peaks of x-ray diffraction (XRD) patterns match well with ICDD card no. 06-0464, which confirms the hexagonal phase of covellite CuS. Scanning electron microscopy (SEM) images reveal the formation of spherical-shaped CuS nanoparticles with mild agglomeration. The presence of Cu and S as the only elements in the synthesized samples is confirmed by energy-dispersive x-ray analysis (EDX). The occurrence of various stretching and bending vibrational modes is observed via Fourier transform infrared (FTIR) spectroscopy. Furthermore, the obtained FTIR spectra of S1, S2, and S3 evince the formation of CuS nanoparticles and the presence of bioactive compounds. The UV-Vis absorption data of the prepared samples reveal that their band gap energies lie within the range of 1.5–1.7 eV. The photoluminescence (PL) spectra of S1, S2, and S3 display decreased intensity, which could be due to the reduced recombination rate of charge carriers. The CuS nanoparticles synthesized with neem leaf extract exhibit relatively smaller crystallite size, wider band gap of 1.7 eV, and a lower recombination rate of charge carriers.

Air pollution, along with climate change, poses significant risks to human health. One of the major contributors to air pollution, particularly in urban areas, is nitrogen dioxide (NO₂). Continuous real-time monitoring of NO₂ is necessary for the protection of human health and the environment. Currently, efforts are concentrated across the globe toward the development of compact NO₂ sensors that exhibit higher responses at lower operating temperatures. In the present work, conductometric gas sensors based on tungsten trioxide (WO₃), tin oxide (SnO₂), and tin oxide–tungsten trioxide (WO₃-SnO₂) composites have been developed using the chemical solution deposition (CSD) technique for NO₂ detection. The investigation of the sensing response was conducted over a range of temperatures, spanning from 30°C to 180°C towards 10 ppm of NO₂. The pristine WO₃ sensor showed a maximum response of ~ 535 at 150°C with a response time of 21 s and recovery time of 126 s, whereas the WO₃-SnO₂ composite sensor showed a maximum response of ~ 209 at a relatively lower temperature of 120°C with a response time of 37 s and recovery time of 135 s. The composite sensor thus shows the potential for the realization of an efficient NO₂ sensor at a lower operating temperature.

The present work reports the findings of “write once read many” (WORM) characteristics in the thin film of an organic dye, Thiazole Yellow G (TYG), when a positive voltage sweep was applied. For a negative voltage sweep, purely ohmic characteristics were observed. During the positive voltage sweep, electron transport took place, and in the negative sweep, hole transport was observed. These voltage sweep-dependent memory characteristics are explained using density functional theory (DFT) calculations for the dye’s highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy level diagram and other theoretical models. High-temperature studies of the device also supported our explanations. Additionally, the device exhibited impressive data retention time of more than 16 h, a large memory window of the order of 10³, a high success rate in device fabrication (yield), and 2000 write/read cycles (endurance). Overall, this device shows promising features due to its distinct charge transport behaviour depending on the voltage sweep direction, making it a potential candidate for future efficient resistive memory applications.

In this paper, we study the effects of Cu, Ni, and Zn doping in TiO₂ layers on the performance of MAPbI₃-based perovskite solar cells (PSCs) fabricated under ambient air with relative humidity between 60% and 70%. One of the factors limiting the efficiency of MAPbI₃-based PSCs is the TiO₂ electron transport layer properties. The efficiency of PSCs is the maximum power that can be produced by a PSC when illuminated by light with a specific energy. This study aims to enhance MAPbI₃-based PSC efficiency by doping TiO₂ with 2 mol.% Cu, Ni, and Zn. MAPbI₃-based PSCs were then fabricated using spin coating with the structure ITO/TiO₂/MAPbI₃/graphite/ITO. X-ray diffraction and scanning electron microscopy (SEM) analyses revealed that doping reduced TiO₂ crystal sizes from 19.34 nm (pure) to 18.96 nm (Cu-doped), 18.04 nm (Ni-doped), and 17.6 nm (Zn-doped), with corresponding average particle sizes of 225 nm, 107 nm, 79 nm, and 50.4 nm. Ultraviolet–visible (UV–Vis) spectroscopy indicated an increase in the bandgap from 3.0 eV (pure) to 3.1 eV (Cu-doped), 3.2 eV (Ni-doped), and 3.25 eV (Zn-doped). Current–voltage (I–V) electrical testing revealed improvement in efficiency from 5.7% (undoped) to 7.6% (Cu-doped), 6.9% (Ni-doped), and 8.01% (Zn-doped). These findings demonstrate that metal-doped TiO₂ significantly enhances the efficiency of MAPbI₃-based PSCs fabricated in open-air environments without the need for a glove box.

Although perovskite solar cells (PSCs) have captured notable interest as a potential candidate for third-generation solar cells, due to their favorable optoelectronic properties, cost-effectiveness, and high efficiency, some issues related to device stability and toxicity of the perovskite (PSK) layer hinders the commercial viability of PSCs. The inherent instability of organic PSK halides and the toxicity of Pb has compelled researchers to focus on developing Pb-free all-inorganic PSCs by replacing the organic species with inorganic (Cs⁺) cations as a safer alternative. In this study, the SCAPS-1D simulator was employed to investigate the cell performances of all-inorganic Pb-free Cs-based PSCs with three different PSK layers (CsGeI₃, CsSnI₃, and Cs₂TiI₆) individually, where inorganic ZnO and CuSCN were used as the electron transport layer (ETL) and the hole transport layer (HTL), respectively. The Cs₂TiI₆-based PSC was found to have the best performance. Then, the defect tolerance level of the PSK layer and the impact of band offset on cell performances were investigated. The optimum values of the conduction band offset (CBO) and the valence band offset (VBO) were found to be 0 eV and between − 0.1 eV and 0 eV, respectively. Moreover, the effect of interface defects at the ETL/PSK and PSK/HTL interfaces on cell performance was also analyzed as a function of CBO and VBO and, for both cases, the interface defect tolerance limit was recorded as 10¹⁶ cm⁻². This study observed a high rate of recombination for negative values of CBO and VBO at the interfaces. Thus, these findings will guide researchers in developing high-performance PSCs with suitable inorganic Pb-free perovskite and charge transport layers.

Structural batteries offer multiple advantages, providing viable solutions for electric mobility. By playing a dual role as both an energy storage device and structural component, they can achieve a larger transportation range and greater safety. However, they are exposed to external mechanical loads that can exacerbate the mechanical stresses induced by the electrochemical cycling. It should be noted that batteries undergo stress due to the intercalation and deintercalation of Li⁺. In fact, when lithium ions are inserted into the active materials, mechanical tension occurs, which can cause cracks and pulverization of the particles. Consequently, the individual particles lose their electrical connectivity. Another aging process is caused by the expansion of the active materials due to mechanical strain during the insertion of lithium ions, resulting in changes in particle volume. In addition to this electrochemical stress, there is added mechanical stress due to their role as a structural component. This paper explores the superposition of these two phenomena and tries to understand the fatigue and failure mechanisms induced by mechanical strain and electrochemical cycling (Li⁺ intercalation/deintercalation) in structural batteries. To achieve this, we plan to use the fiber bundle model as a theoretical approach to study the damage and fracture of fiber-reinforced composite materials.

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Efficient photoelectrochemical photodetectors based on WSe₂/rGO have been fabricated using an annealing process. The initial performance enhancement of these devices was primarily attributed to the improved bandgap structure of WSe₂ and the high carrier mobility of rGO, which facilitated an efficient transition of valence band electrons to the conduction band. Upon this understanding, a comparison between bulk WSe₂ and WSe₂ nanosheets (WSe₂ NSs) was conducted. It was found that, at a bias voltage of 0.6 V, the photocurrent density of WSe₂ NSs devices was 76% higher than that of similar bulk WSe₂ devices, reaching 0.044 μA/cm². Owing to the significant advantages of rGO, extensive testing of various WSe₂ to rGO ratios was performed, identifying the precise composition that optimized photoelectric performance. Notably, under conditions of 0.5 M Na₂SO₄ electrolyte, 120 mW/cm² irradiance, and 0.6 V bias potential, the devices achieved a photocurrent density of 0.64 μA/cm², which is approximately 25.72 times higher than that of bulk WSe₂ and 14.61 times more than WSe₂ NSs. Moreover, the photoresponse trended upward with increasing irradiation intensity. Specifically, when the irradiation intensity was increased to 160 mW/cm² and the bias voltage was raised from 0 V to 0.6 V, the photoresponsivity increased by 5.8 times, from 1 μA/W to 5.8 μA/W. The photodetectors constructed using the optimal WSe₂/rGO ratio exhibited no significant performance degradation during a 4000-s cyclic on/off test, demonstrating their robustness under operational conditions. This study highlights the substantial potential of WSe₂/rGO hybrids in enhancing the performance of photoelectrochemical photodetectors.

This study investigated the interfacial reactions between Co and In-Sn solders, with various compositions, up to 90 at% Sn, at 350°C, with the aim of evaluating their potential for use in the solid–liquid interdiffusion (SLID) process. The results demonstrated that the reaction phases formed at the interfaces exhibited significant variations depending on the Sn content present in the In-Sn solders. For Sn content below 2 at%, the reaction phase was CoIn₃. Notably, the CoIn₃ in the In-2 at% Sn/Co reaction exhibited a linear growth at a rate of ~ 15 μm/h, which was significantly higher compared to the In/Co reaction. The accelerated growth rate could be attributed to the minor addition of Sn, which facilitated both the nucleation and growth of CoIn₃. With an increase in Sn content to 2.5–3.5 at%, the dominant reaction phase shifted to Co(In,Sn)₂, but its growth was significantly hindered. With a further increase in Sn content within the range of 4–35 at%, the irregular Co(Sn,In) phase became dominant. However, as the Sn content exceeded 36 at% and extended up to 90 at%, the Co(Sn,In)₂ phase remained stable at the interface, and its growth decreased significantly with increasing Sn content. The observed shift in the reaction phases is closely related to the local phase equilibrium. The suggested phase diagram of Co-In-Sn system was proposed to further understand the relationship between interfacial reaction and phase equilibrium. The Sn content of In-Sn solders not only influenced the formed reaction phase but also the growth rates and microstructures. Careful control of Sn content is crucial for the SLID process of In-Sn/Co system.

(K,Na)NbO₃(KNN)-based ceramics are a promising lead-free piezoelectric material that could replace Pb(Zr_1−xTi_x)O₃-based materials due to their higher Curie temperature and superior electrical properties. However, the volatilization of sodium and potassium during conventional high-temperature sintering makes it difficult to obtain KNN ceramics with a dense structure and excellent electrical properties. Herein, a conventional solid-phase method combined with microwave sintering is applied for the preparation of KNN ceramics. The influence of the microwave sintering process on the microstructure and electrical properties of KNN ceramics were studied. The optimal microwave sintering conditions for KNN ceramics were determined to be 1100°C for 50 min. Under these conditions, the ceramic samples exhibited excellent ferroelectric properties, with the maximum polarization (P_max) of 20.4 μC/cm² and a remanent polarization (P_r) of 18.1 μC/cm². Additionally, the samples demonstrated impressive piezoelectric properties, including the maximum electric field-induced strain (S_max) of 0.0251%, a dynamic piezoelectric coefficient (d₃₃*) of 125.5 pm/V, and a piezoelectric coefficient (d₃₃) of 109.8 pC/N. The study has important implications for the use of microwave sintering to achieve the densification of the ceramic with volatile elements such as KNN-based ceramics at lower sintering temperature and short sintering time.

The electrolytic cell is the main equipment for electrolytic aluminum production. The visual electrolytic cell can observe and study the production process and mechanism of aluminum electrolysis. The effects of Y₂O₃ addition and sample thickness on the densification behavior and transmittance of Magnesium-aluminate spinel (MAS) were studied. The relative density, porosity, phase composition, microstructure, Vickers hardness, and transmittance of the sintered samples were characterized using the Archimedes method, x-ray diffraction analysis, scanning electron microscopy, Vickers hardness tester, and UV-visible near-infrared diffuse reflection. The results show that the appropriate amount of Y₂O₃ can enhance the transmittance of MgAl₂O₄ and the optimum Y₂O₃ content is 2 wt.%. At this time, the relative density of Magnesium-aluminate spinel (MAS), the maximum hardness, and the maximum transmittance are 96.19%, 18.18 GPa, and 36.3%, respectively. Under the optimum conditions, when the mass of the sample is 0.2 g, the relative density and maximum hardness of the Magnesium-aluminate spinel (MAS) sample are 97.28% and 18.18 GPa, respectively. Although the transmittance is not the highest, it is only lower than the transmittance of 0.15 g sample. The optimum sintering additive content and sample thickness jointly promote the densification, hardness, and transmittance of Magnesium-aluminate spinel (MAS).