Search Results (157)

This study presents a heterogeneous integration micro-assembly process and circuit board packaging solution for GaN Schottky Barrier Diode (SBD) rectifiers, and innovatively constructs a hierarchical reinforcement learning strategy for optimizing SBD RF parameters. By establishing an optimization framework with the goal of efficiency in the load-input power two-dimensional space, a dual-layer optimization mechanism is employed: the high-level strategy dynamically selects optimization regions and parameter combinations, while the low-level strategy implements specific parameter adjustments. This approach effectively addresses the challenges of device parameter modeling and circuit design. Experimental data shows that the efficiency error for the SBD1 rectifier remains stable within 2%, and the average error for SBD2 is reduced to 1.5%. This method enables efficient and accurate optimization of RF parameters, providing a reliable technical pathway for the engineering application of Wireless Power Transmission systems. Full article

CdSe-coated electrodes, formed by electrodeposition of CdSe barrier layers on metallic Ti or porous TiO₂ substrates, were characterized by electrochemical impedance spectroscopy in a (photo)cell using aqueous redox electrolytes based on the sulfide/polysulfide or ferro/ferricyanide couples. The influence of electrode material properties, electrolyte contact, thermal annealing, and measurement conditions (illumination, frequency, potential-scan speed) on the shape and features of Mott–Schottky plots was investigated. The obtained information was evaluated on the basis of the ideal Schottky diode model and photocurrent voltammetry data. Deviations from linear diode behavior and uncertainties in the determination of energetic parameters were examined and attributed to the presence of donor density gradients and surface states in the semiconductor electrode, further complicated by chemical corrosion. The origin of the observed non-idealities is inquired into, and specific aspects of the measuring procedure related to the non-stationary character of the interface are discussed. Full article

Schottky barrier diodes (SBDs) based on low-dimensional materials are of interest for high-speed electronics due to their intrinsic nonlinear transport characteristics. In this work, aligned carbon nanotube Schottky barrier diodes (ACNT-SBDs) were systematically studied through electrical characterization, small-signal modeling, and large-signal nonlinear measurements. Devices with channel widths ranging from 50 to 500 µm were fabricated to examine size-dependent direct-current and high-frequency behavior. Clear Schottky rectification and pronounced geometry-dependent characteristics were observed, with the widest device achieving an intrinsic cutoff frequency of up to 282 GHz. Based on measured S-parameters, a refined small-signal model incorporating a parallel resistance–constant phase element (CPE) branch was developed, providing substantially improved agreement with measured S- and Y-parameters and phase response compared with the classical model. The extracted CPE parameters exhibit systematic dependence on channel width, indicating distributed junction charge dynamics associated with carbon nanotube interfaces. Furthermore, the large-signal nonlinear behavior was evaluated using an anti-parallel diode configuration, achieving a third-harmonic output power of −22.58 dBm at 30 GHz under zero-bias operation. This work provides a comprehensive experimental and modeling framework for understanding the high-frequency and nonlinear behavior of ACNT-SBDs. Full article

Millimeter-wave (mmWave)/terahertz (THz) devices relying on conventional semiconductor technologies face significant performance bottlenecks, constraining their use in next-generation electronic systems. To address these challenges, this work demonstrates high-performance THz Schottky barrier diodes (SBDs) based on aligned carbon nanotube (ACNT) arrays, and the realization of a D-band second-harmonic frequency multiplier. The ACNT-SBDs exhibit superior electrical and radio-frequency (RF) characteristics, achieving a forward current density of 0.14 mA·μm⁻¹ at −1.3 V and an intrinsic cutoff frequency (f_C) of 506 GHz. The developed small-signal model of diodes shows close agreement with measurements, with S-parameter relative errors below 0.7% from 100 MHz to 67 GHz. The implemented 154 GHz D-band multiplier achieved a maximum output power of −18.97 dBm and a minimum conversion loss of 27.92 dB, outperforming previously reported frequency multipliers based on carbon nanotubes or two-dimensional (2D) materials. This study not only establishes the outstanding high-frequency response, nonlinear efficiency, and integration potential of ACNT-based devices but also provides a promising technical pathway for future THz communication and sensing applications. Full article

This paper analyzes microstructural layout and electrical behavior of silicon nanowire-based Schottky diodes, for use as wide-domain temperature sensors. The employed nanostructured three-dimensional substrates provide larger contact areas and enable higher Schottky barrier heights, ultimately leading to a better operable temperature range. Two metal deposition techniques (Radio Frequency sputtering and Electron-beam evaporation) are used to fabricate experimental Schottky diode samples. Scanning electron microscopy, X-ray diffraction, and diffuse reflectance investigations are carried out in order to determine nanowire distribution and the influence of subsequent metal deposition. The analyses evince the formation of a slightly inhomogeneous contact. The findings are validated by a thorough electrical characterization over a wide temperature domain. Inhomogeneity models are used in order to determine the main device parameters and the bias regions where they can be used as precise temperature sensors. The sputtered sample exhibits the best sensitivity, between 1 and 1.4 mV/K, while excellent linearity (R² > 99.5%) is obtained for Electron-beam evaporated devices. Both types of silicon nanowire-based Schottky diode sensors have 100–500K operable ranges, much larger than planar counterparts. Full article

Microwave wireless power transfer (MWPT) technology has the advantages of long distance and high transmission efficiency; therefore, MWPT has many applications in aerospace, space solar power stations (SSPSs), and so on. The receiving and fixing subsystem is the core component for gathering and converting power and it is the main part of the system. If this step is both efficient and possible, the whole system will also be efficient and its success possible. This paper mainly introduces a systematic review of the key technologies, research status, and development trends of the receiving-end part in MWPT. High-performance rectifying devices are analyzed in detail, with the use of GaN Schottky barrier diodes (GaN SBDs), in addition to rectification circuits that have good rectification and impedance matching. Additionally, it compares the advantages and disadvantages of three power synthesis architectures, including RF synthesis, DC synthesis, and hybrid subarray synthesis, and proposes a strategy for optimizing power distribution through intelligent subarray partitioning. Finally, this paper looks at future development trends in receiving-end technology, including miniaturized monolithic microwave integrated circuits (MMICs) and efficient broadband reconfigurable rectification. The research presented herein offers a systematic technical reference and theoretical foundation for enhancing the performance of the receiving ends in microwave wireless power transfer systems. Full article

A vertical Ni/β-Ga₂O₃ Schottky barrier diode was fabricated on an unintentionally doped bulk (−201)-oriented β-Ga₂O₃ single crystal and investigated with a focus on the underlying photoresponse mechanisms. The device exhibits well-defined rectifying behavior, characterized by a Schottky barrier height of 1.63 eV, an ideality factor of 1.39, and a high rectification ratio of ~9.7 × 10⁶ arb. un. at an applied bias of ±2 V. The structures demonstrate pronounced sensitivity to deep-ultraviolet radiation (λ ≤ 280 nm), with maximum responsivity observed at 255 nm, consistent with the wide bandgap of β-Ga₂O₃. Under 254 nm illumination at a power density of 620 μW/cm², the device operates in a self-powered mode, generating an open-circuit voltage of 50 mV and a short-circuit current of 47 pA, confirming efficient separation of photogenerated carriers by the built-in electric field of the Schottky junction. The responsivity and detectivity of the structures increase from 0.18 to 3.87 A/W and from 9.8 × 10⁸ to 4.3 × 10¹¹ Hz^0.5cmW⁻¹, respectively, as the reverse bias rises from 0 to −45 V. The detectors exhibit high-speed performance, with rise and decay times not exceeding 29 ms and 59 ms, respectively, at an applied voltage of 10 V. The studied structures demonstrate internal gain, with the external quantum efficiency reaching 1.8 × 10³%. Full article

This study demonstrates the fabrication of high-performance p-Cu₂O/n-β-Ga₂O₃ heterojunction barrier Schottky (JBS) diodes using copper as a low-work-function anode metal. By optimizing the Cu₂O spacing to 4 μm, the device achieves a turn-on voltage of 0.78 V, a breakdown voltage of 1700 V, and a specific on-resistance of 5.91 mΩ·cm², yielding a power figure of merit of 0.49 GW/cm². The JBS diode also exhibits stable electrical characteristics across the temperature range of 300–425 K. Under a 200 V reverse stress for 5000 s, the JBS diode shows only a 4.16% degradation in turn-on voltage and a 1.15-fold increase in dynamic specific on-resistance variation, highlighting its excellent resistance to stress-induced degradation. These results indicate that Cu₂O/Ga₂O₃ JBS diodes are promising candidates for next-generation high-efficiency and high-voltage power electronic applications. Full article

A Si/SiC heterojunction double-trench MOSFET with improved conduction characteristics is proposed. By replacing the N+ source and P-ch regions with silicon, the device forms a Si/SiC heterojunction that exhibits Schottky-like characteristics, effectively deactivating the parasitic PiN body diode and improving third-quadrant performance. A high-k gate dielectric is incorporated to induce a strong electron accumulation layer at the heterointerface, thinning the energy barrier and enabling tunneling-dominated current transport, thereby significantly enhancing the first-quadrant performance. TCAD simulation results demonstrate that the proposed device achieves a specific on-resistance (R_on,sp) of 1.78 mΩ·cm², representing a 20.5% reduction compared to the conventional SiC DTMOS, while maintaining a comparable breakdown voltage (BV) of approximately 1380 V. A significant reduction in the third-quadrant turn-on voltage (V_on) is achieved with the proposed structure, from 2.74 V to 1.53 V. Meanwhile, the unipolar conduction mechanism similar to that of Schottky effectively suppresses bipolar degradation. To enhance device reliability, the design incorporates a trenched source and heavily doped P-well, which collectively mitigate high electric field concentrations at the trench corners. The proposed device offers an integration strategy enhancing both forward conduction and reverse conduction in high-voltage power electronics. Full article

Thanks to its excellent material properties, diamond-based power electronic devices have garnered widespread attention. The realization of large-sized (over 2 inches) and high-quality single-crystal diamond wafers has significantly accelerated the industrialization of diamond semiconductor materials and devices. Over years of development, diamond Schottky barrier diodes (SBDs) have evolved into three primary device structures: lateral conduction type, quasi-vertical conduction type, and vertical conduction type. However, the performance of these devices has yet to fully unlock the potential of diamond materials. Efficient edge termination structures need to be designed to synergistically optimize the forward turn-on voltage, on-resistance, and off-state breakdown voltage. This paper reviews the research progress on various existing edge termination structures of diamond SBDs, analyzes the advantages of each structure, and discusses the key challenges faced in the device fabrication processes. Full article

Raman thermometry is a powerful technique for sub-microscale thermal measurements on semiconductor-based devices, provided that the active region remains accessible and is not obscured by metallization. Since pure metals do not exhibit Raman scattering, traditional Raman thermometry becomes ineffective in such cases. To overcome this limitation, we propose the use of atomically thin Two-Dimensional materials as local temperature sensors. These materials generate Raman spectra at the nanoscale, enabling highly precise absolute surface temperature measurements. In this study, we investigate the feasibility and effectiveness of this approach by applying it to power devices, including a calibrated gold resistor and an SiC Junction Barrier Schottky (JBS) diode. We assess the processing challenges and measurement reliability of 2D materials for thermal characterization. To validate our findings, we complement Raman thermometry with thermoreflectance measurements, which are well suited for metallized surfaces. For example, on the serpentine resistor, Raman thermometry applied to the 2D material yielded a thermal resistance of 22.099 °C/W, while thermoreflectance on the metallic surface measured 21.898 °C/W. This close agreement suggests good thermal conductance at the metal/2D material interface. The results demonstrate the potential of integrating 2D materials as effective nanoscale temperature probes, offering new insights into thermal management strategies for advanced electronic components. Additionally, thermal simulations are conducted to further analyze the thermal response of these devices under operational conditions. Furthermore, we investigate two 2D material integration methods, transfer and direct growth, and evaluate them through measured thermal resistances for the SiC JBS diode, highlighting the influence of the deposition technique on thermal performance. Full article

Diamond, renowned for its exceptional electrical, physical, and chemical properties, including ultra-wide bandgap, superior hardness, high thermal conductivity, and unparalleled stability, serves as an ideal candidate for next-generation high-power and high-temperature electronic devices. Among diamond-based devices, Schottky barrier diodes (SBDs) have garnered significant attention due to their simple architecture and superior rectifying characteristics. This review systematically summarizes recent advances in diamond SBDs, focusing on both metal–semiconductor (MS) and metal–interlayer–semiconductor (MIS) configurations. For MS structures, we critically analyze the roles of single-layer metals (including noble metals, transition metals, and other metals) and multilayer metals in modulating Schottky barrier height (SBH) and enhancing thermal stability. However, the presence of interface-related issues such as high densities of surface states and Fermi level pinning often leads to poor control of the SBH, limiting device performance and reliability. To address these challenges and achieve high-quality metal/diamond interfaces, researchers have proposed various interface engineering strategies. In particular, the introduction of interfacial layers in MIS structures has emerged as a promising approach. For MIS architectures, functional interlayers—including high-k materials (Al₂O₃, HfO₂, SnO₂) and low-work-function materials (LaB₆, CeB₆)—are evaluated for their efficacy in interface passivation, barrier modulation, and electric field control. Terminal engineering strategies, such as field-plate designs and surface termination treatments, are also highlighted for their role in improving breakdown voltage. Furthermore, we emphasize the limitations in current parameter extraction from current–voltage (I–V) properties and call for a unified new method to accurately determine SBH. This comprehensive analysis provides critical insights into interface engineering strategies and evaluation protocols for high-performance diamond SBDs, paving the way for their reliable deployment in extreme conditions. Full article

In this study, a novel silicon carbide (SiC) double-trench MOSFET (DT-MOS) combined Schottky barrier diode (SBD) and MOS-channel diode (MCD) is proposed and investigated using TCAD simulations. The integrated MCD helps inactivate the parasitic body diode when the device is utilized as a freewheeling diode, eliminating bipolar degradation. The adjustment of SBD position provides an alternative path for reverse conduction and mitigates the electric field distribution near the bottom source trench region. As a result of the Schottky contact adjustment, the reverse conduction characteristics are less influenced by the source oxide thickness, and the breakdown voltage (BV) is largely improved from 800 V to 1069 V. The gate-to-drain capacitance is much lower due to the removal of the bottom oxide, bringing an improvement to the turn-on switching rise time from 2.58 ns to 0.68 ns. These optimized performances indicate the proposed structure with both SBD and MCD has advantages in switching and breakdown characteristics. Full article

This work employs a deep learning method to develop a high-precision model for predicting the breakdown voltage (V_br) and forward I-V characteristics of silicon carbide Schottky barrier diodes (SiC SBDs). The model significantly reduces the testing costs associated with destructive experiments, such as breakdown voltage testing. Although the model requires a certain amount of time to establish itself, it supports linear variations in related variables once developed. A predicted model for V_br with an accuracy of up to 99% was successfully developed using 600 sets of input data after 200 epochs of training. After training for 1000 epochs, the deep learning-based model could predict not only point values like V_br but also curves, such as forward I-V characteristics, with a mean squared error (MSE) of less than 10⁻³. Our research shows the applicability and high efficiency of introducing deep learning into device characteristic prediction. Full article

Gallium Arsenide (GaAs) Schottky technology stands out for its superior performance in terms of conversion loss for terahertz mixers at room temperatures, which establishes it as a dominant solution in receivers for high-data-rate wireless communications. However, Indium Gallium Arsenide (InGaAs) Schottky mixers offer a notable advantage in terms of reduced power requirements due to their lower barrier height, enabling optical pumping with the incorporation of photodiodes acting as photonic local oscillators (LOs). In this study, we present the first comparative analysis of GaAs and InGaAs diode technologies under both electrical and optical pumping, which are also being compared for the first time, particularly in the context of a wireless communication system, transmitting up to 80 Gbps at 0.3 THz using 16-quadrature amplitude modulation (QAM). The terahertz transmitter and the optical receiver’s LO are based on modified uni-traveling-carrier photodiodes (MUTC-PDs) driven by free-running lasers. The investigation covers a total of two mixers, including narrow-band GaAs and InGaAs. The results reveal that, despite InGaAs mixers exhibiting higher conversion loss, the bit error rate (BER) can be as low as that with GaAs. This is attributed to the purity of optically generated LO signals in the receiver. This work positions InGaAs Schottky technology as a compelling candidate for terahertz reception in the context of optical wireless communication systems. Full article