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
CaN-based heterostructures with an InAlCaN/AlCaN composite barrier on sapphire （0001） substrates are grown by a low-pressure metal organic chemical vapor deposition system. Compositions of the InAiGaN layer are dete...CaN-based heterostructures with an InAlCaN/AlCaN composite barrier on sapphire （0001） substrates are grown by a low-pressure metal organic chemical vapor deposition system. Compositions of the InAiGaN layer are determined by x-ray photoelectron spectroscopy, structure and crystal quality of the heterostruetures are identified by high resolution x-ray diffraction, surface morphology of the samples are examined by an atomic force microscope, and Hall effect and capacitance-voltage measurements are performed at room temperature to evaluate the electrical properties of heterostructures. The Al/In ratio of the InAlGaN layer is 4.43, which indicates that the InAlCaN quaternary layer is nearly lattice-matched to the CaN channel. Capacitance-voltage results show that there is no parasitic channel formed between the InAIGaN layer and the AlCaN layer. Compared with the InAl- CaN/CaN heterostructure, the electrical properties of the InAlCaN/AlGaN/GaN heterostructure are improved obviously. Influences of the thickness of the AlGaN layer on the electrical properties of the heterostructures are studied. With the optimal thickness of the AlGaN layer to be 5 nm, the 2DEG mobility, sheet density and the sheet resistance of the sample is 1889.61 cm2/V.s, 1.44 × 10^13 cm-2 and as low as 201.1 Ω/sq, respectively.展开更多
Nearly lattice-matched InAIGaN/GaN heterostructure is grown on sapphire substrates by pulsed metal organic chemical vapor deposition and excellent high electron mobility transistors are fabricated on this heterostruct...Nearly lattice-matched InAIGaN/GaN heterostructure is grown on sapphire substrates by pulsed metal organic chemical vapor deposition and excellent high electron mobility transistors are fabricated on this heterostructure. The electron mobility is 1668.08cm2/V.s together with a high two-dimensional-electron-gas density of 1.43 × 10^13 cm-2 for the InAlCaN/CaN heterostructure of 2Onto InAlCaN quaternary barrier. High electron mobility transistors with gate dimensions of 1 × 50 μm2 and 4μm source-drain distance exhibit the maximum drain current of 763.91 mA/mm, the maximum extrinsic transconductance of 163.13 mS/mm, and current gain and maximum oscillation cutoff frequencies of 11 GHz and 21 GHz, respectively.展开更多
Epitaxial growth of InA1GaN/GaN structures are performed on the c-plane sapphire by pulsed metal organic chemical vapor deposition with different triethylgallium （TEGa） flows in the growth process of InA1GaN qua- te...Epitaxial growth of InA1GaN/GaN structures are performed on the c-plane sapphire by pulsed metal organic chemical vapor deposition with different triethylgallium （TEGa） flows in the growth process of InA1GaN qua- ternary alloys. X-ray photoelectron spectroscopy results show that the A1/In ratio of the samples increases as the TEGa flows increase in the InAIGaN quaternary growth process. High-resolution x-ray diffraction results show that the crystal quality is improved with increasing TEGa flows. Morphology of the InA1GaN/GaN het- erostructures is characterized by an atomic force microscopy, and the growth mode of the InA1GaN quaternary shows a 21） island growth mode. The minimum surface roughness is 0.2Ohm with the TEGa flows equaling to 3.6 μool/rain in rms. Hall effect measurement results show that the highest electron mobilityμ is 1005.49 cm2/Vs and the maximal two-dimensional electron gas is 1.63 × 1013 em-2.展开更多
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 Science and Technology Major Project under Grant No 2013ZX02308-002the National Natural Science Foundation of China under Grant Nos 11435010,61474086 and 61334002
文摘CaN-based heterostructures with an InAlCaN/AlCaN composite barrier on sapphire （0001） substrates are grown by a low-pressure metal organic chemical vapor deposition system. Compositions of the InAiGaN layer are determined by x-ray photoelectron spectroscopy, structure and crystal quality of the heterostruetures are identified by high resolution x-ray diffraction, surface morphology of the samples are examined by an atomic force microscope, and Hall effect and capacitance-voltage measurements are performed at room temperature to evaluate the electrical properties of heterostructures. The Al/In ratio of the InAlGaN layer is 4.43, which indicates that the InAlCaN quaternary layer is nearly lattice-matched to the CaN channel. Capacitance-voltage results show that there is no parasitic channel formed between the InAIGaN layer and the AlCaN layer. Compared with the InAl- CaN/CaN heterostructure, the electrical properties of the InAlCaN/AlGaN/GaN heterostructure are improved obviously. Influences of the thickness of the AlGaN layer on the electrical properties of the heterostructures are studied. With the optimal thickness of the AlGaN layer to be 5 nm, the 2DEG mobility, sheet density and the sheet resistance of the sample is 1889.61 cm2/V.s, 1.44 × 10^13 cm-2 and as low as 201.1 Ω/sq, respectively.
基金Supported by the National Science and Technology Major Project of China under Grant No 2013ZX02308-002the National Natural Sciences Foundation of China under Grant Nos 61574108,61334002,61474086 and 61306017
文摘Nearly lattice-matched InAIGaN/GaN heterostructure is grown on sapphire substrates by pulsed metal organic chemical vapor deposition and excellent high electron mobility transistors are fabricated on this heterostructure. The electron mobility is 1668.08cm2/V.s together with a high two-dimensional-electron-gas density of 1.43 × 10^13 cm-2 for the InAlCaN/CaN heterostructure of 2Onto InAlCaN quaternary barrier. High electron mobility transistors with gate dimensions of 1 × 50 μm2 and 4μm source-drain distance exhibit the maximum drain current of 763.91 mA/mm, the maximum extrinsic transconductance of 163.13 mS/mm, and current gain and maximum oscillation cutoff frequencies of 11 GHz and 21 GHz, respectively.
基金Supported by the National Science and Technology Major Project of China under Grant No 2013ZX02308-002the National Natural Science Foundation of China under Grant Nos 11435010,61474086 and 61334002
文摘Epitaxial growth of InA1GaN/GaN structures are performed on the c-plane sapphire by pulsed metal organic chemical vapor deposition with different triethylgallium （TEGa） flows in the growth process of InA1GaN qua- ternary alloys. X-ray photoelectron spectroscopy results show that the A1/In ratio of the samples increases as the TEGa flows increase in the InAIGaN quaternary growth process. High-resolution x-ray diffraction results show that the crystal quality is improved with increasing TEGa flows. Morphology of the InA1GaN/GaN het- erostructures is characterized by an atomic force microscopy, and the growth mode of the InA1GaN quaternary shows a 21） island growth mode. The minimum surface roughness is 0.2Ohm with the TEGa flows equaling to 3.6 μool/rain in rms. Hall effect measurement results show that the highest electron mobilityμ is 1005.49 cm2/Vs and the maximal two-dimensional electron gas is 1.63 × 1013 em-2.
