Search Results (603)

In this work, a novel understanding of the main failure mechanism of a Schottky p-GaN gate AlGaN/GaN HEMT subject to forward gate stress is reported. First an experimental characterization of the gate leakage current (I_GSS) at different temperatures is reported. Then, Technology Computer Aided Design (TCAD) simulations are used to reproduce the experimental I_GSS thanks to the impact ionization model, also at different temperatures. Simulation results underline how the stressed regions for the Device Under Test (DUT) at high gate biases are the Schottky/p-GaN interface, the p-GaN/AlGaN barrier interface, and p-GaN sidewalls. Moreover, Time Dependent Gate Breakdown (TDGB) measurements were done, and the TEM analysis on the failed device showed the lattice crystal damage located at the p-GaN/AlGaN interface, in accordance with TCAD simulations’ current density distribution at high voltage gate stress. Full article

With the advent of 6G mobile communication, the demand for ultra-high bandwidth wireless communication has increased rapidly, drawing significant attention to visible light communication (VLC) as a promising emerging technology. GaN-based laser diodes (LDs) are regarded as high-speed light sources for VLC owing to their high modulation bandwidth and high optical power density. Apart from the active region design, the LD’s structure also plays a crucial role in determining their dynamic properties, which have yet to be thoroughly studied in III-nitride LDs. In this work, we systematically investigate InGaN/GaN laser diodes with three ridge waveguide configurations: a conventional single-ridge structure, a dual-ridge large-mesa structure, and a dual-ridge small-mesa structure. The threshold current, small-signal modulation bandwidth of devices with different structures are comparatively analyzed. Experimental results reveal that the double-ridge small mesa laser diode achieves a modulation bandwidth of −3 dB at 6.02 GHz. These results provide valuable insights into the structural optimization of GaN-based high-speed laser diodes and offer practical guidance for the development of high-performance, energy-efficient VLC transmitters. Full article

Wide-bandgap (WBG) semiconductors are propelling a paradigm shift in advanced power electronics, offering functionality that includes higher-switching-frequency operation with improved efficiency and power density possibilities. Gallium nitride (GaN) exhibits unique material properties that correspond to device parameters beneficial for achieving an improved performance compared to its counterparts. The inception of GaN power semiconductor devices has enabled advanced power electronics to realize efficient and compact power converters. However, the current rating of the devices is constrained, and paralleling of the devices is vital to realize high-currentrated power modules. Furthermore, paralleling of the devices can provide improved cooling results in high-power-density systems. This paper presents a comprehensive review study of the paralleling of GaN devices to discuss the different challenges associated with paralleling. One of the fundamental challenges is associated with the design of a structure for paralleling GaN devices. The parallel device structure consequently impacts the parasitics of the device, which limit the operating switching frequency and thermo-mechanical aspects. Furthermore, power loop inductance, gate loop inductance asymmetry, common-source inductance, gate inductance trace length mismatch, and different challenges lead to design trade-offs and efforts to optimize the design by realizing an appropriate trade-off, considering low-inductance packaging along with thermal strategies, and considering a parallel circuit layout and structure. Considering the recent research trends and studies related to the design of parallel GaN devices, this paper presents future perspectives anticipating the realization of an improved parallel GaN device structure. Full article

The accelerating adoption of electric vehicles (EVs) is driving the demand for next-generation wide-bandgap (WBG) power devices that can deliver high efficiency, high power density, and robust operation under stringent electrical and thermal stress. Gallium nitride (GaN) high-electron-mobility transistors (HEMTs) have emerged as a leading WBG technology due to their high breakdown voltage, ultrafast switching capability, and low conduction and switching losses relative to silicon devices, enabling high-performance EV power converters such as on-board chargers, DC-DC converters, and traction inverters. This review provides a comprehensive device-level assessment of GaN HEMTs, emphasizing advanced device architectures, state-of-the-art discrete transistors, and their implications for high-frequency, high-efficiency power conversion. Critical performance and reliability challenges, including current collapse, self-heating, and gate degradation, are analyzed in the context of their physical mechanisms and operational behavior under realistic conditions such as elevated junction temperatures, high switching frequencies, and dynamic load profiles. Furthermore, emerging opportunities in ultra-wide-bandgap semiconductor technologies beyond GaN are discussed, providing insights to guide the design, optimization, and robust integration of WBG devices into next-generation EV power electronic systems. Full article

Power density and power efficiency are crucial for the design of high-performance computing servers. Buck converters exist due to their simplicity, but achieving a solution that combines high efficiency and high power density remains an ongoing research area in buck converter design. High-frequency switching, which reduces inductor size in buck converters, is a common method for achieving high power density; however, high-frequency switching introduces higher switching losses, hence the frequent use of GaN HEMTs, which have low switching losses. To achieve both high efficiency and high power density, this study proposes a compact buck converter design that pairs a D-type GaN HEMT with a low-voltage PMOS, termed a P-cascode GaN HEMT. We analyze different current switching modes and find that boundary conduction mode (BCM) can minimize inductor size while maintaining high power efficiency. This paper explores the theoretical basis of BCM and the P-cascode GaN HEMT, derives the operating conditions of BCM, estimates power efficiency, and proposes a high-power density buck converter solution. Simulation and experimental results show that the proposed design achieves 95% power efficiency in applications from 12 V to 3.3 V, while reducing the inductor size by a factor of 10 compared to continuous conduction mode (CCM) designs. Full article

This study proposes a 300 W class Gallium Nitride (GaN) Solid-State Power Amplifier (SSPA)-based microwave plasma generator system for implementing next-generation light sources with high brightness and color rendering at 2.45 GHz. To overcome the lifetime limitations and control constraints of conventional magnetron systems, the proposed system introduces custom packaging technology utilizing GaN-on-SiC Bare-dies fabricated via the Win-semiconductor’s NP25 process. This approach minimizes parasitic components and significantly reduces thermal resistance compared to standard packages, ensuring reliability during high-power operation. A stable RF output of 300 W was achieved through two-stage power combining. For the plasma source, an Ar-InBr-Hg gas mixture was employed to optimize optical characteristics. This gas mixture is commonly used in electrodeless plasma lamps due to its high luminous efficacy and stable discharge characteristics. To analyze the rapid impedance discontinuity during gas ignition, numerical analysis based on the Drude model was performed, theoretically identifying the complex permittivity transition of the medium and the resulting resonant frequency up-shift mechanism. To mitigate system instability during this transition, an adaptive frequency tracking and feedback control loop based on real-time VSWR monitoring was implemented. Experimental results demonstrate precise tracking within a 100 MHz frequency variable range, achieving a system efficiency of over 53% and maintaining a VSWR below 1.15:1. These results validate the practical feasibility of GaN SSPA technology in electrodeless lighting and industrial plasma applications utilizing high-power RF energy. Full article

Wide bandgap (WBG) semiconductors such as gallium nitride (GaN) and silicon carbide (SiC) have revolutionized modern power electronics by enabling devices that operate at higher voltages, temperatures, and switching frequencies than their silicon counterparts. This paper reviews the material properties, device architectures, fabrication techniques, and thermal management strategies that underpin the performance of GaN and SiC technologies. We highlight key trade-offs between GaN and SiC in terms of voltage blocking capability, switching efficiency, and thermal robustness and discussed their application in electric vehicles, renewable energy systems, and power converters. Market adoption trends and manufacturing challenges are also analyzed, with attention to cost-performance dynamics and packaging innovations. Finally, we address the critical role of thermal boundary resistance and emerging reliability solutions, providing a perspective on the future trajectory of WBG device research and commercialization. Full article

Hybrid nanomaterials that integrate surface functionality, colloidal stability, and efficient electron-transfer pathways are highly attractive for improving electrochemical sensing performance. Herein, we report the fabrication and evaluation of polyethyleneimine-functionalized gallium nitride nanoparticles (GaN) decorated with gold nanoparticles (GaN-PEI-Au) as a tunable electrode modifier for enhanced differential pulse voltammetry (DPV) detection of erythromycin. Branched polyethyleneimine was employed as a multifunctional interfacial layer to stabilize GaN dispersions, introduce amine-rich surface chemistry, and enable in situ gold nanoparticle formation at the GaN-PEI. The optimized GaN-PEI-Au material exhibited high colloidal stability, a characteristic Au localized surface plasmon resonance in the ~520–525 nm range, and well-defined Au nanoparticles attached to the GaN surface. When applied as an electrode coating, GaN-PEI-Au significantly enhanced the erythromycin oxidation response compared to bare Au and GaN-PEI interfaces, consistent with synergistic increases in electroactive surface area and interfacial charge-transfer efficiency. Under optimized DPV conditions, GaN-PEI-Au-modified electrodes enabled quantitative erythromycin determination with a linear range of 5 nM–2 µM (R² = 0.990), sensitivity of 1.32 × 10⁻³ µA nM⁻¹, and a limit of detection of 52.5 nM, while maintaining stable baseline behavior during repeated scans. The reported GaN-PEI-Au nanocomposites represent a robust platform for sensitive electrochemical detection of pharmaceutical compounds. Full article

As a critical pretreatment process for chemical and mechanical polishing (CMP), the lapping roughness of gallium nitride (GaN) crystals directly influences the outcome of subsequent polishing and the reliability of final devices. This study systematically investigates the key factors affecting the lapping performance of GaN single crystals, focusing on abrasive type, particle size, and spindle speed, and elucidates their mechanisms in regulating material removal rate (MRR) and surface roughness. Using a micro-thickness gauge and controlled variable method, the material removal depth of the (0001) plane of GaN was accurately measured. The results show that the MRR increases with the increase in abrasive particle size within a certain range, albeit at the cost of increased surface roughness. Meanwhile, the spindle speed and MRR exhibit a positive correlation under specific conditions. Considering these lapping parameters, a balance between high MRR and controlled roughness can be achieved, providing a technical foundation for efficient and precise lapping of GaN crystals and facilitating the fabrication of GaN-based devices. Full article

The transition from conventional synchronous generators to inverter-based power systems has introduced significant challenges in stability, reliability, and protection coordination. Grid-forming inverters (GFMs) have emerged as a promising solution by emulating inertia and voltage regulation functions while enabling grid-supportive operation in weak or islanded networks. This study presents a structured qualitative review of the recent literature on GFM technologies. The selection process focused on control strategies, advanced semiconductor materials, protection frameworks, and cyber–physical security considerations. A thematic synthesis and comparative analysis were conducted to identify emerging trends and technical gaps. Among established approaches, virtual synchronous machine (VSM) and droop control remain widely adopted. More advanced strategies, including virtual oscillator control (VOC) and model predictive control (MPC), demonstrate improved dynamic performance in weak-grid conditions. Advances in semiconductor technologies, particularly Silicon Carbide (SiC) and Gallium Nitride (GaN), enable faster switching, higher efficiency, and enhanced thermal performance. The findings indicate a growing shift toward decentralized control architectures, fault-resilient converter topologies, and integrated protection–control co-design. Emerging solutions include grid-forming synchronization techniques that replace conventional phase-locked loop (PLL) structures, intrusion-tolerant inverter firmware with embedded anomaly detection, and predictive fault-clearing schemes tailored for low-inertia networks. Despite these advancements, several research gaps remain. These include limited large-scale validation of VOC and MPC strategies under high renewable penetration, insufficient interoperability metrics for legacy system integration, and a lack of standardized cybersecurity benchmarks across platforms. Future research should prioritize real-time experimental validation, robust protection co-design methodologies, and the development of regulatory and dynamic performance standards tailored to inverter-dominated grids. Strengthening protection coordination and interoperability frameworks will be essential to ensure the secure and stable deployment of GFMs in modern power systems. Full article

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

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

This review analyzes the transition from silicon to wide-bandgap (WBG) and ultrawide-bandgap (UWBG) semiconductor materials for power electronics, focusing on Silicon Carbide (SiC) and Gallium Nitride (GaN) technologies. Following a PRISMA-based systematic review methodology, we analyzed 94 peer-reviewed publications spanning device technology, converter architectures, and system applications. We employ a bottom-up approach, progressing from fundamental material properties through device architectures and converter topologies to system-level implications. We examine how intrinsic material properties enable operation at elevated temperatures, voltages, and frequencies while minimizing losses. Through analysis of Figures of Merit and system-level Key Performance Indicators, we quantify WBG benefits across automotive, industrial, renewable energy, and consumer electronics sectors, demonstrating 3–5× power density improvements and 20–40% cost reductions. The review presents emerging device technologies, including vertical GaN for medium-voltage applications and monolithic bidirectional switches (BDSs), enabling single-stage power conversion. We provide the first comprehensive topology-level comparison of emerging vertical GaN and monolithic bidirectional switches against established SiC solutions, identifying specific applications where each technology offers advantages. A comprehensive topology-by-topology comparison between SiC and GaN is provided, offering design guidelines for device selection. The review addresses practical constraints, including dynamic on-resistance degradation, threshold voltage instability, and electromagnetic interference challenges for both SiC and GaN. Finally, we examine emerging UWBG materials ($\beta$-Ga₂O₃, AlN, c-BN, Diamond) and their development status, manufacturing challenges, supply chain considerations, and commercialization prospects for ultra-high-voltage applications. Full article

Self-heating effects severely limit the performance of gallium nitride high-electron-mobility transistors (GaN HEMTs) in high-power radio frequency (RF) applications. Diamond capping technology leveraging diamond’s exceptional thermal conductivity (>2000 W/m·K) has emerged as a highly promising near-junction cooling solution. However, its integration with GaN HEMTs faces challenges including lattice/thermal mismatch, high thermal boundary resistance (TBR), and process compatibility. This review summarizes recent progress in high-thermal-conductivity diamond film growth, TBR optimization, thermal simulations, and the integrated process with GaN devices. These technological breakthroughs enable diamond-capped GaN HEMTs with an excellent comprehensive performance. Continued advances in these fields will be critical for fully releasing the capabilities of diamond capping technology for GaN HEMTs in high-frequency and high-power applications. Full article

The rapid increase in electric vehicle (EV) adoption necessitates advanced charging infrastructures that are compact, efficient, and capable of bidirectional power flow for both vehicle-to-grid (V2G) and grid-to-vehicle (G2V) operation. Unlike traditional silicon and SiC-based chargers, this work introduces a Ga₂O₃-based bidirectional smart charging system integrated with a hybrid energy storage system to deliver superior performance. A coordinated control strategy is developed to regulate power sharing between a supercapacitor and a lithium-ion battery pack, thereby extending battery life, reducing current stress, and providing effective transient support. This hybrid system employs PI-based control and advanced modulation techniques to minimize current ripple, maintain the unity power factor, and ensure stable DC-link voltage regulation. MATLAB/Simulink simulation results demonstrate robust DC-link stability, smooth bidirectional power transfer, and very low total harmonic distortion. Comparative loss analysis shows that Ga₂O₃ MOSFETs offer significantly lower conduction and switching losses, enabling efficiencies up to 98% across the rated operating range. These results confirm that the proposed charger is highly suitable for next-generation EV infrastructures requiring high power density, reliable grid interfacing, and enhanced operational longevity. A hardware prototype was also developed and tested, with experimental results validating reliable grid-side performance and efficient energy sharing under typical operating conditions. Full article