- 标题
- 摘要
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- 实验方案
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Ultrahigh Breakdown Strength and Energy Density in PLZST@ PBSAZM Antiferroelectric Ceramics Based on Core-shell Structure
摘要： A novel core-shell structured Pb0.91La0.06(Zr0.552Sn0.368Ti0.08)O3@PbO–B2O3-SiO2-Al2O3-ZnO-MnO2 (PLZST@PBSAZM) antiferroelectric particles were successfully fabricated via sol-gel method. As expected, the sintering temperature was notably reduced from 1250 oC to 1100 oC with the increasing glass contents. More importantly, the breakdown strengths of PLZST@PBSAZM ceramics were significantly increased from 252 kV/cm to 402 kV/cm. As a result, the energy density was up to 7.4 J/cm3 with 1 wt.% of coating glass content, a 55.3% enhancement over the pure PLZST (4.7 J/cm3). Furthermore, the simulations of electric field distribution provided a powerful evidence that the enhancement of the breakdown strength was induced by the core-shell structure, since the glass coating layer could not only undertake the most of electric field, but also impede the grain growth to achieve the smaller grains, which led to the reduction of electric field intensity on the grain cores.
关键词： Core-shell structured,Antiferroelectric,Breakdown strength,Energy density
更新于2025-09-23 15:19:57
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Thickness-tunable growth of ultra-large, continuous and high-dielectric h-BN thin films
摘要： The outstanding thermal properties, mechanical properties and large optical bandgap of hexagonal boron nitride (h-BN) make it very attractive for various applications in ultrathin 2D microelectronics. However, the synthesis of large lateral size and uniform h-BN thin films with a high breakdown strength still remains a great challenge. Here, we comprehensively investigated the effect of growth conditions on the thickness of h-BN films via low pressure chemical vapor deposition (LPCVD). By optimizing the LPCVD growth parameters with electropolished Cu foils as the deposition substrates and developing customized "enclosure" quartz-boat reactors, we achieved thickness-tunable (1.50–10.30 nm) growth of h-BN thin films with a smooth surface (RMS roughness is 0.26 nm) and an ultra-large area (1.0 cm × 1.0 cm), meanwhile, the as-grown h-BN films exhibited an ultra-high breakdown strength of ~10.0 MV cm?1, which is highly promising for the development of electrically reliable 2D microelectronic devices with an ultrathin feature.
关键词： dielectric breakdown strength,h-BN,thin films,LPCVD,2D microelectronics,hexagonal boron nitride
更新于2025-09-19 17:15:36
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Passive Quenching Electronics for Geiger Mode 4H-SiC Avalanche Photodiodes
摘要： We design and fabricate 4H-SiC UV avalanche photodiodes (APDs) with positive beveled mesa, which exhibit low leakage current and high avalanche gain when working in the Geiger mode. The single photon counting performance of the SiC APDs is studied by using a passive-quenching circuit. A new method to determine the exact breakdown voltage of the APD is proposed based on the initial emergence of photon count pulses. The photon count rate and dark count rate of the APD are also evaluated as a function of quenching resistance.
关键词： 4H-SiC,single photon counting,passive quenching,Geiger mode,avalanche photodiodes,breakdown voltage
更新于2025-09-19 17:15:36
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Source-field-plated Ga <sub/>2</sub> O <sub/>3</sub> MOSFET with a breakdown voltage of 550 V
摘要： Ga2O3 metal–oxide–semiconductor field-effect transistors (MOSFETs) with high-breakdown characteristics were fabricated on a homoepitaxial n-typed β-Ga2O3 film, which was grown by metal organic chemical vapor deposition (MOCVD) on an Fe-doped semi-insulating (010) Ga2O3 substrate. The structure consisted of a 400 nm unintentionally doped (UID) Ga2O3 buffer layer and an 80 nm Si-doped channel layer. A high k HfO2 gate dielectric film formed by atomic layer deposition was employed to reduce the gate leakage. Moreover, a source-connected field plate was introduced to enhance the breakdown characteristics. The drain saturation current density of the fabricated device reached 101 mA/mm at Vgs of 3 V. The off-state current was as low as 7.1 × 10?11 A/mm, and the drain current ION/IOFF ratio reached 109. The transistors exhibited three-terminal off-state breakdown voltages of 450 and 550 V, corresponding to gate-to-drain spacing of 4 and 8 μm, respectively.
关键词： MOSFET,Ga2O3,filed plate,breakdown voltage
更新于2025-09-19 17:15:36
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Silicon photomultipliers with area up to 9 mm2 in a 0.35 μm CMOS process
摘要： Silicon photomultipliers produced using standard complementary metal oxide semiconductor (CMOS) processes are at the basis of modern applications of sensors for weak photon fluxes. They allow in fact to integrate transistor-based electronic components within sensors and provide intelligent read-out strategies. In this paper we investigate the scalability of a 0.35 μm CMOS process to large area devices. We report the design and characterization of SiPMs with a total area of 1 mm2, 4 mm2 and 9 mm2. Cross talk, photon detection efficiency at 420 nm, gain at 2.5 V overvoltage and breakdown voltage temperature coefficient do not depend on the total area of the sensor and are 10%, 35%, 2.5 × 106 and 35 mV/K respectively. The dark count rate scales with the total area of the device as 180 kHz/mm2. The total output capacitance, the decay time of the single photon signal and the single photon time resolution depend on the area of the device. We obtain a capacitance of 66.9 pF, 270.2 pF and 554.0 pF, a decay time of (27.1 ± 0.1) ns, (50.8 ± 0.1) ns and (78.2 ± 0.1) ns and a single photon time resolution of (77.97 ± 0.51) ps, (201.67 ± 0.98) ps and (282.28 ± 0.86) ps for the 1 mm2, 4 mm2 and 9 mm2 SiPMs respectively.
关键词： CMOS,Silicon photomultiplier (SiPM),avalanche breakdown structures,Sensors for Brain Positron Emission Tomography
更新于2025-09-19 17:15:36
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Fully-vertical GaN-on-Si power MOSFETs
摘要： We report the first demonstration of fully-vertical power MOSFETs on 6.6-μm-thick GaN grown on a 6-inch Si substrate by metal-organic chemical vapor deposition (MOCVD). A robust fabrication method was developed based on a selective and local removal of the Si substrate as well as the resistive GaN buffer layers, followed by a conformal deposition of a 35-μm-thick copper layer on the backside by electroplating, which provides excellent mechanical stability and electrical contact to the drain terminal. The fabrication process of the gate trench was optimized, improving considerably the effective mobility at the p-GaN channel and the output current of the devices. High performance fully-vertical GaN-on-Si MOSFETs are presented, with low specific on-resistance (Ron,sp) of 5 m?cm2 and high off-state breakdown voltage (BV) of 520 V. Our results reveal a major step towards the realization of high performance GaN vertical power devices on cost-effective Si substrates.
关键词： power devices,GaN,low Ron,sp,GaN-on-Si,fully-vertical,MOSFETs,vertical,high breakdown
更新于2025-09-19 17:15:36
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Forensic soil analysis using laser-induced breakdown spectroscopy (LIBS) and Fourier transform infrared total attenuated reflectance spectroscopy (FTIR-ATR): Principles and case studies
摘要： Soils are crucial trace evidence that can establish or exclude the relationship between a suspect, victim, or an object at a particular scene, which could contribute to building a case. Laser-induced breakdown spectroscopy (LIBS) and Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy have been demonstrated to be effective techniques for soil characterization owing to its being rapid, non-destructive, and convenient analysis with little sample preparation requirements. Therefore, the principles of LIBS and FTIR-ATR techniques for soil forensic analysis in typical soil samples were investigated and their practical feasibility was tested by applying the techniques to forensic soil samples in two criminal cases. Principal component analysis (PCA) of a typical soil sample indicated that five typical soil types were clearly distinguished by LIBS and FTIR-ATR spectra. Variations in the soil elements (i.e., Si, Mg, Al, Ca, K, O, and N) and functional groups (i.e., O?H/N?H, C=C/C=O, Si?O, CO3 2?, Al?OH, and NH2) are crucial indicators for soil identification. The casework results demonstrated that both LIBS and FTIR-ATR show great potential for forensic soil analysis in future cases.
关键词： forensics,laser-induced breakdown spectroscopy,criminalistics,Soil identification,mid-infrared attenuated reflectance spectroscopy
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Computed tomography dataset analysis for stereotaxic neurosurgery navigation
摘要： First-ever 28 nm embedded split-gate MONOS (SG-MONOS) ?ash macros have been developed to increase memory capacity embedded in micro controller units and to improve performance over wide junction temperature range from C to 170 C as demanded strongly in automotive uses. Much attention has been paid to the degradation of the reliability characteristics along with the process shrinkage. Temperature-adjusted word-line overdrive scheme improves random read access frequency by 15% and realizes both of 6.4 GB/s read throughput by 200 MHz no-wait random access of code ?ash macros and more than ten times longer TDDB lifetime of WL drivers. Temperature-adaptive step pulse erase control (TASPEC) improves the TDDB lifetime of dielectric ?lms between metal interconnect layers by three times. TASPEC is particularly useful for a data ?ash macro with one million rewrite cycles. Source-side injection (SSI) program with negative back-bias voltage achieves 63% reduction of program pulse time and, consequently, realizes 2.0 MB/s write throughput of code ?ash macros. A spread spectrum clock generation and a clock phase shift technique are introduced for charge pump clock generation in order to suppress EMI noise due to high write throughput of code ?ash macros, and peak power of EMI noise is reduced by 19 dB.
关键词： high-temperature operation,time dependent dielectric breakdown,Automotive application,high reliability,spread spectrum clock generation,word-line over-drive,split-gate MONOS(SG-MONOS),embedded ?ash memory,Fast random read operation
更新于2025-09-19 17:13:59
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Gap-surface Plasmon Metasurfaces for Structured Beams Generation
摘要： The curvature effect of the 3-D layout may result in a severe deterioration of the breakdown voltage in a power lateral double-diffused MOS (LDMOS). In this paper, a novel 3-D analytical model is proposed to provide the physical insight of curvature effect in small radius region by solving the 3-D Poisson in cylindrical coordinates. The proposed model indicates that the curvature effect equivalently changes the drift region doping concentration, thus altering the surface electric field profile. The proposed 3-D model can accurately describe the surface field profile in the fingertip regions of the multifinger layout, and provides an effective way to reveal the influence of curvature effect on the performance of silicon-on-insulator LDMOS. Furthermore, based on the proposed model, a corresponding structure optimization criterion is derived to provide a simple but effective method for the device structure parameters optimization.
关键词： multifinger layout,breakdown voltage (BV),small radius region,curvature effect,3-D model
更新于2025-09-19 17:13:59
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Improved breakdown strength of Poly(vinylidene Fluoride)-based composites by using all ball-milled hexagonal boron nitride sheets without centrifugation
摘要： Hexagonal boron nitride (h-BN) is an ideal candidate to endow ferroelectric polymers with high energy density ((cid:1)(cid:2)) due to its intrinsic high breakdown strength ((cid:3)(cid:4)) of 800 kV/mm. Generally, it is believed that only boron nitride nanosheets (BNNSs) could remarkably improve (cid:3)(cid:4) of composite. Nevertheless, low-yield and time-consuming preparation procedures of BNNSs greatly limits the application of h-BN. To overcome this challenge, in this study, all ball-milled h-BN (B-BN) sheets were entirely used to enhance (cid:3)(cid:4) of poly(vinylidene fluoride) (PVDF) without any further centrifugation. (cid:3)(cid:4) of composites increased as ball-milling time increases at filler content of 8 wt%. Remarkably, PVDF with h-BN ball-milled for 16 h (B16-BN) possesses an impressive (cid:3)(cid:4) value of 506.8 kV/mm, which is 2.86 times that of neat PVDF (272.4 kV/mm) and even 1.33 times higher than that of PVDF/h-BN composites (380.6 kV/mm). (cid:3)(cid:4) of PVDF/B16-BN composites is close to that of PVDF/OH-BNNSs composites at same filler content, suggesting that the centrifugation is not a necessary procedure. Besides, improved dielectric loss, calculated (cid:1)(cid:2), mechanical properties and in-plane thermal conductivity can also be achieved for PVDF/B16-BN composites. These improved properties of PVDF/B16-BN composites indicate that the employment of B16-BN can avoid the weakness of low-yield and time-consuming preparation procedure of BNNSs and broaden its applications in the field of energy storage. Finally, the improved dispersion of OH-BN as well as synergy effect (f) on (cid:3)(cid:4) between OH-BN and OH-BNNSs were discussed to better understand these improved properties of PVDF/B16-BN composites.
关键词： Breakdown strength,No centrifugation,Synergy effect,Hexagonal boron nitride
更新于2025-09-19 17:13:59