Under electron beam irradiation,the in-situ formation of 2H-SiC dentritic nanocrystals from amorphous silicon carbide at room temperature was observed.The homogenous transition mainly occurs at the thin edge and on th...Under electron beam irradiation,the in-situ formation of 2H-SiC dentritic nanocrystals from amorphous silicon carbide at room temperature was observed.The homogenous transition mainly occurs at the thin edge and on the surface of specimen where the energy obtained from electron beam irradiation is high enough to cause the amorphous crystallizing into 2H-SiC.展开更多
We present comprehensive first-principles calculations on the initial stages of SiC oxidation by atomic oxygen on the 2H-SiC(001) surface. In order to study the kinetics of oxygen incorporation at the 2H-SiC(001) surf...We present comprehensive first-principles calculations on the initial stages of SiC oxidation by atomic oxygen on the 2H-SiC(001) surface. In order to study the kinetics of oxygen incorporation at the 2H-SiC(001) surface, we investigated adsorption and diffusion of oxygen atoms and SiO2 nucleation. The adsorption sites, corresponding to the local minima of the potential energy surface (PES) for iso-lated adatoms, were identified through a comparative study of the adatom binding energy at different locations. We found that the Bridge (siloxane) site is preferred over other adsorption sites. There is no energy barrier at 0K for oxygen insertion into this site. The diffusion energy barriers that the adatom has to overcome when jumping between two adsorption sites were calculated. The premises of silica nucleation were investigated by calculating the modifications of the oxygen atom binding energy due to the interaction with neighboring adatoms.展开更多
In this paper,we propose a near-infrared p-type β-FeSi2/n-type 4H-SiC heterojunction photodetector with semiconducting silicide（β-FeSi2） as the active region for the first time.The optoelectronic characteristics o...In this paper,we propose a near-infrared p-type β-FeSi2/n-type 4H-SiC heterojunction photodetector with semiconducting silicide（β-FeSi2） as the active region for the first time.The optoelectronic characteristics of the photodetector are simulated using a commercial simulator at room temperature.The results show that the photodetector has a good rectifying character and a good response to near-infrared light.Interface states should be minimized to obtain a lower reverse leakage current.The response spectrum of the β-FeSi2/4H-SiC detector,which consists of a p-type β-FeSi2 absorption layer with a doping concentration of 1×1015cm-3 and a thickness of 2.5 μm,has a peak of 755 mA/W at 1.42 μm.The illumination of the SiC side obtains a higher responsivity than that of the β-FeSi2 side.The results illustrate that the β-FeSi2/4H-SiC heterojunction can be used as a near-infrared photodetector compatible with near-infrared optically-activated SiC-based power switching devices.展开更多
A high-quality Ga2O3 thin film is deposited on an SiC substrate to form a heterojunction structure. The band alignment of the Ga2O3/6H-SiC heterojunction is studied by using synchrotron radiation photoelectron spectro...A high-quality Ga2O3 thin film is deposited on an SiC substrate to form a heterojunction structure. The band alignment of the Ga2O3/6H-SiC heterojunction is studied by using synchrotron radiation photoelectron spectroscopy, The energy band diagram of the Ga2O3/6H-SiC heterojunction is obtained by analysing the binding energies of Ga 3d and Si 2p at the surface and the interface of the heterojunction. The valence band offset is experimentally determined to be 2.8 eV and the conduction band offset is calculated to be 0.89 eV, which indicate a type-II band alignment. This provides useful guidance for the application of Ga2O3/6H-SiC electronic devices.展开更多
We give the first report on the experimental investigation of a p-β-FeSi2/n-4H-SiC heterojunction. A β-/%FeSiE/n-4H-SiC heterojunction near-infrared photodiode was fabricated on 4H-SiC substrate by magnetron sputter...We give the first report on the experimental investigation of a p-β-FeSi2/n-4H-SiC heterojunction. A β-/%FeSiE/n-4H-SiC heterojunction near-infrared photodiode was fabricated on 4H-SiC substrate by magnetron sputtering and rapid thermal annealing （RTA）. Sharp film-substrate interfaces were confirmed by scanning elec-tron microscopy （SEM）. The current density-voltage and photoresponse characteristics were measured. The measurements showed that the device exhibited good rectifying properties. The photocurrent density was about 1.82 mA/cm^2 at a bias voltage of -1 V under illumination by a 5 mW, 1.31 μm laser, and the dark current density was approximately 0.537 mA/cm^2. The detectivity was estimated to be 8.8×10^9 cmHzl/2/W at 1.31 μm. All of the measurements were made at room temperature. The results suggest that the p-β-FeSiE/n-4H-SiC heterojunctions can be used as near-infrared photodiodes that are applicable to optically-activated SiC-based devices.展开更多
基金Project supproted by the National Natural Science Foundation of China(60025409 and 50472068)National"863"High Technology Plan(2001AA311080)Program for New Century Excellent Talents in Shangdong University
文摘Under electron beam irradiation,the in-situ formation of 2H-SiC dentritic nanocrystals from amorphous silicon carbide at room temperature was observed.The homogenous transition mainly occurs at the thin edge and on the surface of specimen where the energy obtained from electron beam irradiation is high enough to cause the amorphous crystallizing into 2H-SiC.
基金Supported by Snecma Propulsion Solide (Contract FPR No. 0539298A)Natural Science Foundation of China (Grant No 50802076)Flying Star Program of Northwestern Polytechnical University of China
文摘We present comprehensive first-principles calculations on the initial stages of SiC oxidation by atomic oxygen on the 2H-SiC(001) surface. In order to study the kinetics of oxygen incorporation at the 2H-SiC(001) surface, we investigated adsorption and diffusion of oxygen atoms and SiO2 nucleation. The adsorption sites, corresponding to the local minima of the potential energy surface (PES) for iso-lated adatoms, were identified through a comparative study of the adatom binding energy at different locations. We found that the Bridge (siloxane) site is preferred over other adsorption sites. There is no energy barrier at 0K for oxygen insertion into this site. The diffusion energy barriers that the adatom has to overcome when jumping between two adsorption sites were calculated. The premises of silica nucleation were investigated by calculating the modifications of the oxygen atom binding energy due to the interaction with neighboring adatoms.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60876050 and 51177134)
文摘In this paper,we propose a near-infrared p-type β-FeSi2/n-type 4H-SiC heterojunction photodetector with semiconducting silicide（β-FeSi2） as the active region for the first time.The optoelectronic characteristics of the photodetector are simulated using a commercial simulator at room temperature.The results show that the photodetector has a good rectifying character and a good response to near-infrared light.Interface states should be minimized to obtain a lower reverse leakage current.The response spectrum of the β-FeSi2/4H-SiC detector,which consists of a p-type β-FeSi2 absorption layer with a doping concentration of 1×1015cm-3 and a thickness of 2.5 μm,has a peak of 755 mA/W at 1.42 μm.The illumination of the SiC side obtains a higher responsivity than that of the β-FeSi2 side.The results illustrate that the β-FeSi2/4H-SiC heterojunction can be used as a near-infrared photodetector compatible with near-infrared optically-activated SiC-based power switching devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.50702071 and 50772122)the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.51002176)
文摘A high-quality Ga2O3 thin film is deposited on an SiC substrate to form a heterojunction structure. The band alignment of the Ga2O3/6H-SiC heterojunction is studied by using synchrotron radiation photoelectron spectroscopy, The energy band diagram of the Ga2O3/6H-SiC heterojunction is obtained by analysing the binding energies of Ga 3d and Si 2p at the surface and the interface of the heterojunction. The valence band offset is experimentally determined to be 2.8 eV and the conduction band offset is calculated to be 0.89 eV, which indicate a type-II band alignment. This provides useful guidance for the application of Ga2O3/6H-SiC electronic devices.
基金Project supported by the National Natural Science Foundation of China(No.51177134)
文摘We give the first report on the experimental investigation of a p-β-FeSi2/n-4H-SiC heterojunction. A β-/%FeSiE/n-4H-SiC heterojunction near-infrared photodiode was fabricated on 4H-SiC substrate by magnetron sputtering and rapid thermal annealing （RTA）. Sharp film-substrate interfaces were confirmed by scanning elec-tron microscopy （SEM）. The current density-voltage and photoresponse characteristics were measured. The measurements showed that the device exhibited good rectifying properties. The photocurrent density was about 1.82 mA/cm^2 at a bias voltage of -1 V under illumination by a 5 mW, 1.31 μm laser, and the dark current density was approximately 0.537 mA/cm^2. The detectivity was estimated to be 8.8×10^9 cmHzl/2/W at 1.31 μm. All of the measurements were made at room temperature. The results suggest that the p-β-FeSiE/n-4H-SiC heterojunctions can be used as near-infrared photodiodes that are applicable to optically-activated SiC-based devices.
