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Oxygen-incorporated single-photon sources observed at the surface of silicon carbide crystals
摘要： The formation of high-brightness single-photon sources (SPSs) that emit single photons at room temperature was recently con?rmed in oxygen-annealed SiC semiconductors (surface SPSs.) However, the defect structure of surface SPSs remains unclear, which makes device fabrication and property control dif?cult. To verify the incorporation of oxygen in surface SPSs, we fabricated SPSs using stable 18O isotopes as oxidants. By comparing this to the case of natural oxygen annealing, we found that the SP emission spectra for the 18O sample tended to have shorter peak wavelengths, slightly narrower peak widths, and higher intensities. Thus, it appeared that, in the case of the 18O sample, the phonon sideband was located closer to the zero-phonon line and that oxygen was incorporated into the defects attributed to the surface SPS.
关键词： single-photon sources,single defect,silicon carbide,oxygen isotope,semiconductors,photoluminescence
更新于2025-09-09 09:28:46
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Recent Developments Accelerating SiC Adoption
摘要： The benefits of SiC devices for use in power electronics has been long understood, and over 25 years of sustained development in materials and devices has brought adoption to a tipping point [1,15]. It takes the confluence of many separate developments to build the necessary momentum for accelerated adoption, and we will examine these factors.
关键词： SiC MOSFET,SiC reliability,SiC Schottky Diode,SiC gate oxide,SiC Cascode,Supercascode,Silicon Carbide,SiC,SiC packaging,SiC applications,SiC epitaxy,SiC substrates
更新于2025-09-09 09:28:46
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Thermodynamic Analysis of the Growth of Silicon Carbide Ingots in a Reducing Atmosphere
摘要： We have analyzed phase equilibria in the Si–C–H–Ar system during silicon carbide ingot growth by the modified Lely method. The results indicate that the addition of even small amounts of hydrogen to an inert carrier gas leads to a sharp increase in the rate of carbon transport through the gas phase, mediated by volatile hydrocarbons, primarily acetylene, and prevents carbon enrichment in the solid source and corrosion of the graphite equipment in the single-crystal seed region.
关键词： silicon carbide,modified Lely method,hydrogen,thermodynamic analysis
更新于2025-09-09 09:28:46
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Spark Plasma Sintering of Silicon Carbide with Al <sub/>2</sub> O <sub/>3</sub> and CaO: Densification Behavior, Phase Evolution and Mechanical Properties
摘要： Liquid phase sintering (LPS) often yield an amorphous grain boundary region which deteriorates the high temperature properties of the sintered ceramics and thus ceramists prefer to obtain a crystalline grain boundary after LPS. This paper deals with LPS of silicon carbide ceramics to near theoretical density, understanding the densification behavior, evolution of gehlenite phase and subsequent evaluation of their mechanical properties. High density SiC ceramics were fabricated from sub-micrometre α-SiC powders with the aid of refractory phase forming metal oxide additives by spark plasma sintering. Sintering temperature and holding time at peak temperature were varied to study their effect on densification and mechanical properties. Density of the sintered ceramics reached ~97% at 1800oC. Microstructural features and crack propagation mode were studied using scanning electron microscopy. XRD analysis confirmed the presence of crystalline gehlenite phase in the sintered samples. Hardness, fracture toughness and flexural strength of the sintered ceramics were determined by standard test procedures.
关键词： Liquid phase sintering,Fracture toughness,Spark plasma sintering,Silicon carbide,Mechanical properties
更新于2025-09-09 09:28:46
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Electronic structures and optical properties of IV A elements-doped 3C-SiC from density functional calculations
摘要： Electronic structures and optical properties of IV A elements (Ge, Sn and Pb)-doped 3C-SiC are investigated by means of the first-principles calculation. The results reveal that the structure of Ge-doped system is more stable with a lower formation energy of 1.249 eV compared with those of Sn- and Pb-doped 3C-SiC systems of 3.360 eV and 5.476 eV, respectively. Doping of the IV A elements can increase the band gap, and there is an obvious transition from an indirect band gap to a direct band gap. Furthermore, charge difference density analysis proves that the covalent order of bonding between the doping atoms and the C atoms is Ge–C > Sn–C > Pb–C, which is fully verified by population values. Due to the lower static dielectric constant, the service life of 3C-SiC dramatically improved in production practice. Moreover, the lower reflectivity and absorption peak in the visible region, implying its wide application foreground in photoelectric devices.
关键词： electronic structures,Silicon carbide,first-principles simulations,optical properties
更新于2025-09-09 09:28:46
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Ultrafast optical control of multiple coherent phonons in silicon carbide using a pulse-shaping technique
摘要： We demonstrated ultrafast optical control of multiple coherent phonons in silicon carbide (SiC) using a pulse-shaping technique combined with sub-10-fs optical pulses and a two-dimensional spatial light modulator. Because our technique produces a pulse train with the desired number of pulses and time intervals, precise manipulation of the amplitudes of the zone-folded optical and acoustic phonon modes could be achieved simultaneously and was well reproduced by a model calculation assuming the two modes are excited independently by each pulse. These results show that our scheme can provide high controllability of multiple phonon modes in SiC.
关键词： pulse-shaping technique,coherent phonons,ultrafast optical control,silicon carbide
更新于2025-09-09 09:28:46
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High-Q-factor nanobeam photonic crystal cavities in bulk silicon carbide
摘要： Silicon carbide (SiC) is a promising optical material for stable and broadband nanophotonics. To date, thin crystalline SiC layers for nanophotonic platforms have been created by ion implantation or growth on other materials, which may cause optical absorption in the SiC layer. We fabricated SiC nanobeam photonic crystal cavities directly from a crystalline (4H) SiC bulk wafer using oblique plasma etching to avoid material-based optical absorptions. The measured quality (Q) factor of the nanobeam photonic crystal cavity reaches 4 (cid:2) 104, which is the highest recorded Q factor in crystalline SiC cavities. Furthermore, we investigated theoretical Q factors by taking into account structural imperfections unique to this fabrication process and compared them with the experimental results.
关键词： oblique plasma etching,nanobeam photonic crystal cavities,structural imperfections,Silicon carbide,quality factor
更新于2025-09-09 09:28:46
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Analysis of Forward Surge Performance of SiC Schottky Diodes
摘要： Silicon Carbide JBS diodes are capable, in forward bias, of carrying surge current of magnitude significantly higher than their rated current, for short periods. In this work, we examine the mechanisms of device failure due to excess surge current by analyzing variation of failure current with device current and voltage ratings, as well as duration of current surge. Physical failure analysis is carried out to correlate to electrical failure signature. We also quantify the impact, on surge current capability, of the resistance of the anode ohmic contact to the p-shielding region.
关键词： MPS,JBS,SiC,Diode,Surge,SBD,Silicon Carbide,Schottky,Reliability
更新于2025-09-09 09:28:46
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Stored energy release in neutron irradiated silicon carbide
摘要： The purpose of this investigation is to experimentally quantify the stored energy release upon thermal annealing of previously irradiated high-purity silicon carbide (SiC.) Samples of highly-faulted poly-crystalline CVD b-SiC and single crystal 6HeSiC were irradiated in a mixed spectrum ?ssion reactor near 60 (cid:1)C in a ?uence range from 5 (cid:3) 1023 to 2 (cid:3) 1026 n/m2 (E > 0.1 MeV), or about 0.05e20 dpa, in order to quantify the stored energy release and correlate the release to the observed microscopic swelling, lattice dilation, and microstructure as observed through TEM. Within the ?uence of this study the crystalline material was observed to swell to a remarkable extent, achieving 8.13% dilation, and then cross a threshold dose for amorphization at approximately 1 (cid:3) 1025 n/m2 (E > 0.1 MeV) Once amorphized the material attains an as-amorphized swelling of 11.7% at this irradiation condition. Coincident with the extraordinary swelling obtained for the crystalline SiC, an equally impressive stored energy release of greater than 2500 J/g at the critical threshold for amorphization is inferred. As expected, following amorphization the stored energy in the structure diminishes, measured to be approximately 590 J/g. Generally, the ?ndings of stored energy are consistent with existing theory, though the amount of stored energy given the large observed crystalline strain is remarkable. The overall conclusion of this work ?nds comparable stored energy in SiC to that of nuclear graphite, and similar to graphite, a stored energy release in excess of its speci?c heat in some irradiation conditions.
关键词： Neutron irradiation,Amorphization,Silicon carbide,Swelling,Stored energy
更新于2025-09-04 15:30:14
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Structural and optical studies of gamma irradiated N-doped 4H-SiC
摘要： In this paper, the gamma irradiation effects on the structural and optical properties of N-doped 4H-SiC (n-4H-SiC) is presented up to a cumulative gamma radiation dose of 1500 kGy. The studies showed marginal and inconsistent variation in the - and -axis lattice constants of 4H-SiC due to the accumulation of gamma-induced defect states. The modifications in the longitudinal optical plasmon-phonon coupled (LOPC) modes, Biedermann absorption bands, Urbach energy ( ) and defect related photoluminescence (DPL) bands are discussed at different (500, 1000 and 1500 kGy) irradiation doses. Despite these effects, the overall gamma-induced disorder ( ) and variation in the free carrier concentrations ( ) are found to be negligible and demonstrating the radiation resistant property of n-4H-SiC under gamma radiation environment.
关键词： PL,Silicon carbide,XRD,LOPC modes,Gamma irradiation
更新于2025-09-04 15:30:14