Zincblende CrSb （zb-CrSb） layers with room-temperature ferromagnetism have been grown on relaxed and strained （In,Ga）As buffer layers epitaxially prepared on （001） GaAs substrates by molecular-beam epitaxy. The ...Zincblende CrSb （zb-CrSb） layers with room-temperature ferromagnetism have been grown on relaxed and strained （In,Ga）As buffer layers epitaxially prepared on （001） GaAs substrates by molecular-beam epitaxy. The structural characterizations of CrSb layers fabricated under the two cases are studied by using synchrotron grazing incidence x-ray diffraction （GID）. The results of GID experiments indicate that no sign of second phase exists in all the zb-CrSb layers. Superconducting quantum interference device measurements demonstrate that the thickness of zb-CrSb layers grown on both relaxed and strained （In,Ga）As buffer layers can be increased to ～12 monolayers （～3.6nm）, compared to ,～3 monolayers （～1 nm） on GaAs directly.展开更多
Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored ...Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored in the photodetecting area. Considering the fact that the electrical properties such as carrier mobility, work function, and energy band structure of Bi2O2Se are thickness-dependent, the in-plane Bi2O2Se homojunctions consisting of layers with different thicknesses are successfully synthesized by the chemical vapor deposition(CVD) method across the terraces on the mica substrates,where terraces are created in the mica surface layer peeling off process. In this way, effective internal electrical fields are built up along the Bi2O2Se homojunctions, exhibiting diode-like rectification behavior with an on/off ratio of 102, what is more, thus obtained photodetectors possess highly sensitive and ultrafast features, with a maximum photoresponsivity of 2.5 A/W and a lifetime of 4.8 μs. Comparing with the Bi2O2Se uniform thin films, the photo-electric conversion efficiency is greatly improved for the in-plane homojunctions.展开更多
The oxidation of formic acid on edge-truncated cubic platinum nanoparticles/C catalysts is investigated. X-ray photoelectron spectroscopy analysis indicates that the surface of edge-truncated cubic platinum nanopartic...The oxidation of formic acid on edge-truncated cubic platinum nanoparticles/C catalysts is investigated. X-ray photoelectron spectroscopy analysis indicates that the surface of edge-truncated cubic platinum nanoparticles is composed of two types of coordination sites. ＇/＇he oxidation behavior of formic acid on edge-truncated cubic platinum nanoparticles/C is investigated using cyclic voltammetry. The apparent activation energies are found to be 54.2, 55.0, 61.8, 69.5, 71.9, 69.26, 65.28k J/tool at 0.15, 0.3, 0.4, 0.5, 0.6, 0.65, 0.7V, respectively. A specific surface area activity of 1.76 mA·cm^-2 at 0.4 V indicates that the edge-truncated cubic Platinum nanoparticles are a promising anode catalyst for direct formic acid fuel cells.展开更多
This paper has systematically investigated the substrate temperature and thickness dependence of surface morphology and magnetic property of CrAs compound films grown on GaAs by molecular-beam epitaxy. It finds that t...This paper has systematically investigated the substrate temperature and thickness dependence of surface morphology and magnetic property of CrAs compound films grown on GaAs by molecular-beam epitaxy. It finds that the substrate temperature affects the surface morphology and magnetic property of CrAs thin film more potently than the thickness.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10334030, and the Special Funds for Major State Basic Research Project of China under Grant No G2001CB3095, The authors thank Professor Yang Fu-Hua and Wang Yu-Tian for their help in experiments.
文摘Zincblende CrSb （zb-CrSb） layers with room-temperature ferromagnetism have been grown on relaxed and strained （In,Ga）As buffer layers epitaxially prepared on （001） GaAs substrates by molecular-beam epitaxy. The structural characterizations of CrSb layers fabricated under the two cases are studied by using synchrotron grazing incidence x-ray diffraction （GID）. The results of GID experiments indicate that no sign of second phase exists in all the zb-CrSb layers. Superconducting quantum interference device measurements demonstrate that the thickness of zb-CrSb layers grown on both relaxed and strained （In,Ga）As buffer layers can be increased to ～12 monolayers （～3.6nm）, compared to ,～3 monolayers （～1 nm） on GaAs directly.
基金Project supported by the National Natural Science Foundation of China(Grant No.61705066)the Open Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications),China(Grant No.IPOC2018B004)the National Key Research and Development Program,China(Grant No.2016YFA0202401)
文摘Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored in the photodetecting area. Considering the fact that the electrical properties such as carrier mobility, work function, and energy band structure of Bi2O2Se are thickness-dependent, the in-plane Bi2O2Se homojunctions consisting of layers with different thicknesses are successfully synthesized by the chemical vapor deposition(CVD) method across the terraces on the mica substrates,where terraces are created in the mica surface layer peeling off process. In this way, effective internal electrical fields are built up along the Bi2O2Se homojunctions, exhibiting diode-like rectification behavior with an on/off ratio of 102, what is more, thus obtained photodetectors possess highly sensitive and ultrafast features, with a maximum photoresponsivity of 2.5 A/W and a lifetime of 4.8 μs. Comparing with the Bi2O2Se uniform thin films, the photo-electric conversion efficiency is greatly improved for the in-plane homojunctions.
文摘The oxidation of formic acid on edge-truncated cubic platinum nanoparticles/C catalysts is investigated. X-ray photoelectron spectroscopy analysis indicates that the surface of edge-truncated cubic platinum nanoparticles is composed of two types of coordination sites. ＇/＇he oxidation behavior of formic acid on edge-truncated cubic platinum nanoparticles/C is investigated using cyclic voltammetry. The apparent activation energies are found to be 54.2, 55.0, 61.8, 69.5, 71.9, 69.26, 65.28k J/tool at 0.15, 0.3, 0.4, 0.5, 0.6, 0.65, 0.7V, respectively. A specific surface area activity of 1.76 mA·cm^-2 at 0.4 V indicates that the edge-truncated cubic Platinum nanoparticles are a promising anode catalyst for direct formic acid fuel cells.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10334030, 10425419 and 60521001）. Acknowledgments The authors acknowledge Professor Z.C. Niu, Professor F.H. Yang and Professor H.Z. Zheng for useful discussion.
文摘This paper has systematically investigated the substrate temperature and thickness dependence of surface morphology and magnetic property of CrAs compound films grown on GaAs by molecular-beam epitaxy. It finds that the substrate temperature affects the surface morphology and magnetic property of CrAs thin film more potently than the thickness.
