Search Results (2,947)

Accurate and efficient modeling of AlGaN/GaN HEMTs is essential for the design of next-generation power electronics. This study introduces a hybrid Auxiliary Classifier Generative Adversarial Network (ACGAN)–mixup data augmentation framework to enhance deep neural network application in AlGaN/GaN high-electron-mobility transistor modeling with limited data. Based on only 20 distinctive devices, ACGAN uses technology computer-aided design (TCAD)-calibrated data to generate high-quality synthetic drain current ($I_{ds}$) under various electronic bias conditions. The quality of the generated data is validated via Jensen–Shannon divergence with an average of 0.0341. A one-dimensional convolutional neural network (1D-CNN) predictive model is trained on augmented data and achieves stable convergence, with a mean absolute error of 0.002 A/mm for the off-state $I_{ds}$ and 0.052 A/mm for the linear region. It also shows improved robustness over the model trained on original non-augmented data. The proposed approach offers a low-cost alternative to resource-intensive TCAD simulations, enabling accurate device modeling with limited data. Full article

Reliability assessment of semiconductor devices increasingly requires the consideration of multiple degradation mechanisms acting simultaneously over long stress durations. Conventional lifetime qualification and prediction approaches rely on simplified assumptions that can obscure the interpretation of measured degradation data and lead to large uncertainty when extrapolated over many orders of magnitude in time. A consistent analytical framework is therefore required to relate measured degradation behavior to meaningful reliability metrics. This work presents a general framework for semiconductor device reliability that is consistent with established reliability theory and explicitly accommodates multiple competing degradation mechanisms, consistent with modern JEDEC reliability standards. The framework presented here separates physical degradation processes from analytical representations used to interpret experimental data, allowing the effect of independent mechanisms to be combined without imposing an implied physical model. Degradation behaviors exhibiting sublinear time dependence, which are commonly observed across device technologies, are discussed within this context. We show that common data interpretation practices can introduce systematic errors when ssublinearkinetics are present, particularly regarding lifetime extrapolation. A reformulated analytical representation is introduced that improves clarity and robustness in lifetime extraction while remaining fully compatible with standard reliability theory. This framework supports more consistent reliability assessment and more credible lifetime prediction across materials, devices, and operating conditions. Full article

Deposition of amorphous boron (a-B) onto Si substrates via chemical decomposition of B₂H₆ molecules produces a-B/Si, heterojunctions which are the core parts of photodetectors used in vacuum ultraviolet (VUV) and potentially in extreme ultraviolet (EUV) lithography. However, fundamental questions regarding the limit on the thickness of the deposited a-B thin films and the intrinsic electronic nature of the B atoms adjacent to the Si substrate remain unanswered. Here we investigated the local structural and electronic properties of atomic-thin a-B layers at the Si{001} substrates using ab initio molecular dynamics (AIMD) techniques. The investigation revealed a rich variety of local chemical bonding and consequently interfacial electronic properties. For thin a-B layer(s)/Si systems, most of the a-B atoms at the interface formed (-B-Si-B-Si-) chains on the Si{001} surface. These B atoms were found to occupy the positions of the missing Si atoms and were bonded to the surficial Si atoms. The surficial Si atoms predominantly have two B neighbors. Localized defect states at the Fermi level for the interfacial Si and B atoms were found in the pseudo-gap. These states have a major influence on the electrical properties of the device. The predicted minimum thickness of the a-B films is about 1 to 2 nm, a useful metric for the manufacturing of a-B/Si devices. The information obtained here further helps us to understand the working mechanisms of a-B/Si interfaces for photon detection and constructing new core devices for potential applications in the field of metal/semiconductor heterojunctions for photon detection, photovoltaics, Schottky diodes and semiconductor devices. Full article

Organic semiconductors have the potential to contribute to sustainable electronics manufacture due to their ability to be processed from low-energy solution-processing methods. However, improvements must be made in the lifetime of such devices. PEDOT:PSS, a popular hole transport material, is acidic, which causes degradation in devices over time. Therefore, a replacement is needed to allow for longer lasting organic semiconductor devices. We have previously reported BEDOTPy, a non-acidic, molecular material that could be used to improve the device lifetime of OLEDs. In this work we explore how molecular engineering of BEDOTPy, by modifying the molecule’s side chain, affects the physical properties that are important to device performance and lifetime. Full article

As a new full Heusler compound, the Cr₂ZrP alloy has attracted significant attention due to its potential applications in spintronics. In this paper, the electronic, magnetic, and mechanical properties of the Cr₂ZrP alloy were systematically studied using first-principles calculations. The results show that the alloy is a half-metallic ferromagnet with high stability: it exhibits majority-spin-channel semiconductor behavior and minority-spin-channel metallic behavior at the Fermi level, with 100% spin polarization. The total magnetic moment is 3.00 μB, which is consistent with the Slater-Pauling behavior of half-metallic ferromagnets. When the lattice parameter changes by ±5%, the total magnetic moment and 100% spin polarization remain robust, demonstrating excellent mechanical magnetic coupling stability. The mechanical property analysis further revealed that Cr₂ZrP meets the mechanical stability criterion of the cubic system and has a high bulk modulus (~172.8 GPa) and a high Debye temperature (~377 K). At the same time, its Pugh ratio (B/G ≈ 2.96) and Poisson ratio (ν ≈ 0.35) showed that the material had good ductility. The three-dimensional surface plot of Young’s modulus confirmed the obvious anisotropy of mechanical properties. This study theoretically confirmed that the Cr₂ZrP alloy exhibits ideal half-metallic properties, robust magnetic order, good mechanical stability, and ductility, making it a promising candidate for future spintronic devices. Full article

Phase-change materials of the Ge–Sb–Te (GST) system are promising for non-volatile memory and programmable photonics owing to their reversible amorphous–crystalline transitions. Among these materials, GeSb₄Te₇ stands out for its optimal balance of thermal stability, switching speed, and energy efficiency. The properties of GST materials are critically dependent on structural defects, particularly germanium vacancies that occur during synthesis and operation. Using density functional theory, we demonstrate that Ge vacancies and Ge–Sb intermixing significantly influence the electronic and optical properties of GeSb₄Te₇. Positive binding energies reveal vacancy clustering tendencies, which systematically reduce p-type degeneracy and widen the band gap (from 0.47 to 0.67 eV at a 2.7% vacancy concentration). Consequently, the metallic optical response in the visible range diminishes, as reflected in the less negative real dielectric function. Furthermore, we extend our investigation to the fundamental building block of this material system, the GeSb₂Te₄ monolayer. By studying controlled interlayer displacements of Ge and Te atoms in an otherwise stoichiometric slab, we elucidate the switching mechanism in the two-dimensional limit. The pristine monolayer exhibits semiconducting behavior with an indirect band gap of 0.74 eV, while layer sliding induces a semiconductor-to-metal transition accompanied by pronounced changes in the optical absorption spectrum. The asymmetric energy barrier (1.69 eV forward, 0.60 eV reverse) suggests favorable reversible switching via structural distortions alone, without requiring chemical modifications. The obtained results, spanning from defective bulk crystals to structurally distorted monolayers, are important for the targeted optimization of GST material properties in memory devices, optical elements, and emerging nanoscale phase-change applications. Full article

This paper presents an in-depth analysis of a non-isolated buck–boost DC–DC converter which uses coupled inductors. The converter is designed to achieve a high static conversion ratio while using a moderate number of semiconductor devices. The proposed topology, originally introduced in a former paper of the authors, under ideal operating conditions, is now evaluated taking into account non-ideal components, modeling the conduction losses of the semiconductor devices and the equivalent series resistance of the output capacitor. In order to get a regulated output voltage, closed-loop behavior is also investigated. By using the state-space modeling approach, the calculation of the converter static conversion ratio and control-to-output transfer functions is performed. Because the topology is of fourth order, a procedure for controller design is provided. A type III error amplifier is chosen, and the pole-zero placement technique is used for its design, demonstrating that the classical control strategy still works even with this fourth-order converter. Thus, a good phase margin of 62.3 degrees is achieved. The theoretical results are validated both on open-loop and closed-loop operation, in the presence of conduction losses. Furthermore, a laboratory prototype is implemented, and it validates the theoretical and simulation results. The study demonstrates that the proposed coupled inductors buck–boost converter is a good choice for step-up applications that need a large difference between input and output voltages. Full article

A polarization-insensitive compact optical modulator based on a graphene-hybrid surface plasmon polariton waveguide is proposed. The inverted U-shaped structure enables the synchronous control of TE/TM modes via Fermi level tuning, achieving a maximum attenuation of 0.247 dB/μm (E_f = 0.3 eV) and a minimum attenuation of 0.026–0.028 dB/μm (E_f = 1.0 eV) at 3 THz, with a polarization-dependent modulation error of only 0.002 dB/μm. The 100 μm × 30 μm device operates effectively at 2.5 THz (120 μm), demonstrating its potential for integrated photonic circuits. Additionally, the proposed modulator is compatible with Complementary Metal-Oxide-Semiconductor (CMOS) technology. The excellent ultra-broadband modulation performance of the graphene-hybrid plasmonic waveguide (GHPW) thereby paves the way for high-speed communication, non-destructive testing, biomedical sensing and optical computing. Full article

The next evolution in power electronics is being driven by wide-bandgap materials—particularly silicon carbide and gallium nitride power semiconductor devices—which increase efficiency and power density, thus ensuring their integration into high-performance systems. One system poised to receive benefits from this progression is microgrids. This paper reviews common microgrid architectures, components, voltage and power levels, and power electronics to establish where wide-bandgap materials, specifically silicon carbide and gallium nitride, may benefit current and future microgrids. Full article

Two-dimensional magnetic materials with weak spin-orbit coupling would endow them with great potential for applications in low-power spintronic logic devices. In this work, the stability and magnetism of nonmetal (N, O, F, P) doped 1T-ZrS₂ monolayers is systematically studied by using first principles calculations based on density functional theory. Pristine ZrS₂ monolayer is a nonmagnetic semiconductor with an indirect band gap of 1.15 eV. Among the configurations of nonmetal-atom adsorption, substitutional doping, and vacancy defects, fluorine adsorption on the ZrS₂ monolayer is regarded as an optimal doping strategy. At the concentration of 11.11% in F-adsorbed ZrS₂, the spontaneous magnetization of F-adsorbed ZrS₂ monolayer occurs at the ground state with the stable magnetic states; the magnetic moments are about 0.674 μ_B, which mainly originates from the hybridization between the p-orbitals of S atoms and F atoms (0.315 μ_B) and d-orbitals of Zr atoms (0.323 μ_B). Moreover, the F-adsorbed ZrS₂ monolayer under 0–4% strain delivers consistently low spin polarization energy with stable p-d hybridization, offering their promising potential for their practical applications in low-power spintronic devices. Full article

Tunnel Field-Effect Transistors (TFETs) are being explored for ultra-low-power very-large-scale integrated circuits (VLSI) because their band-to-band tunnelling (BTBT) transport permits subthreshold swings (SS) below the 60 mV/dec thermionic limit at room temperature, along with significantly lower leakage than MOSFETs. This paper presents a systematic TCAD study of DG-TFETs that maps how four primary knobs–gate dielectric materials, silicon channel thickness, temperature variation, and different channel material shape key figures of merit: the ON current (I_ON), OFF current (I_OFF), threshold voltage (V_TH), SS, and the I_ON/I_OFF switching ratio. High-k gate enhances gate-to-channel coupling and boost tunnelling efficiency; rigorous body scaling enhances electrostatic control; and targeted source-proximal doping profiles elevate I_ON while minimizing leakage. We also measure the trade-offs between I_ON, SS, and I_OFF that occur when scaling is performed at the same time. This shows that careful coordination is needed instead of just tuning one parameter. This is a simulated work, and the physical models are calibrated to experimental TFET data and all parameters are checked against previously reported results. The device reaches SS = 31.4 mV/dec, V_TH = 0.46 V, I_ON = 5.91 × 10⁻⁵ A and an I_ON/I_OFF of about 4.5 × 10¹¹. This shows that it can switch quickly with little leakage. The design insights that come from this work provide useful advice regarding how to choose gate dielectric material, structures, and doping strategies to add DG-TFETs to the next generation of low-power semiconductor technologies. Full article

Lithographic patterning continues to evolve under the dual pressure of ever-finer features and manufacturable, cost-effective integration. Beyond headline resolution, industrial adoption is increasingly determined by a small set of coupled metrics: throughput, overlay (registration), defectivity, and cost, as well as by how these trade-offs shift with materials, substrate form factors, and integration flows. Here, we review lithographic techniques across three eras: traditional methods (pre-1990s), non-conventional innovations (1990s), and contemporary advancements (post-2000s), with an explicit goal that goes beyond compilation. Specifically, we provide a decision framework for interpreting each method using the same manufacturing-relevant criteria. For each class of technique, we summarize the operating principle and representative process routes, then map the dominant bottlenecks to the metric that ultimately limits scale-up. This cross-cutting lens clarifies why many emerging methods are compelling at the physics level yet remain constrained at the system level, where process windows, in-line control, and compatibility with existing fabrication ecosystems govern viability. By connecting mechanism-level innovation to manufacturing-level constraints, this review offers practical guidance for researchers and engineers seeking to position nanolithography options for applications ranging from high-volume semiconductor production to agile prototyping and materials- or substrate-limited devices. Full article

This paper presents an overview of fault-tolerance strategies in multilevel converters, with emphasis on fault diagnosis as a fundamental stage. Classical multilevel converter topologies and their main application areas, such as motor drives, renewable energy systems, and smart grids, are first introduced, along with the most common faults affecting power semiconductor devices. Fault diagnosis techniques reported in the literature are then reviewed and classified into model-based, signal-based, hardware-based, and hybrid approaches. The operating principles, measured variables, and implementation requirements of each category are analyzed, with particular attention to the fault detection times. A comparative analysis is provided, highlighting the fastest diagnostic strategies and their application to different multilevel converter topologies. This review consolidates recent advances and identifies current trends and challenges, providing a useful reference for the development of faster and more reliable fault-tolerant solutions in multilevel power converters. Full article

This review provides a comprehensive overview of molecular doping in organic semiconductors (OSCs), with particular emphasis on the mechanistic understanding of doping processes, rational material design strategies, and processing approaches for achieving high doping efficiency and stability. We discuss fundamental doping mechanisms, including integer charge transfer and orbital hybridization models, and highlight how molecular structure, polymer design, and dopant–host interactions influence electrical performance. Recent advances in processing strategies—such as sequential, vapor-phase, and hybrid doping methods—are also summarized in relation to microstructural control and charge transport optimization. In addition, the implications of molecular doping for emerging organic thermoelectric applications are addressed, emphasizing the interplay between dopant distribution, morphology, and device performance. By integrating mechanistic insights, material design principles, and application perspectives, this review aims to provide a unified framework for researchers in organic electronics, materials science, and thermoelectric device engineering seeking to develop highly efficient and stable molecularly doped organic conductors. Full article

In this work, we investigate the effect of ligand chemistry on the optical and electrical properties of copper indium disulphide (CuInS₂) quantum dots (QDs) and evaluate their suitability for photodetection with simple device structures. CuInS₂ QDs capped with dodecanethiol (DDT) ligands were synthesized, followed by processes to exchange the DDT with thioglycolic acid (TGA), mercaptopropionic acid (MPA), or thioacetamide (TAA) ligands. Photoluminescence (PL) and UV-Visible absorption studies revealed that while TGA- and MPA-capped QDs retained strong emission, TAA-capped QDs exhibited significant quenching, indicating surface defect formation due to poor ligand binding. Metal–semiconductor–metal (MSM) test structures were fabricated using the QD films as the active layer to study their electrical properties under dark and UV-illuminated conditions. Devices based on MPA- and TGA-capped QD films demonstrated currents that were 7–9 times higher than those of devices with native DDT ligands, with significantly enhanced photocurrent-to-dark current ratios of 2.6 and 1.7, respectively, highlighting the effective charge transport pathways enabled by the shorter ligands. The device with TGA-capped QD film also responded well to 20 kHz pulsed UV excitation, underscoring the strong potential of this simple MSM structure for photodetection and optical switching applications. Full article