The samples of Au/（Si/SiO2 ）/p-Si structure were fabricated by using the R. F magnetron sputtering technique. Its carrier transport and electroluminescence mechanism were studied from the Ⅰ-Ⅴ curves and EL spectra...The samples of Au/（Si/SiO2 ）/p-Si structure were fabricated by using the R. F magnetron sputtering technique. Its carrier transport and electroluminescence mechanism were studied from the Ⅰ-Ⅴ curves and EL spectra by using the Configuration Coordinate as a theoretical model. The result indicates that there are two defect centers in SiO2 films. The electron in Au and the hole in p-Si went into SiO2 film by the Fowler-Nordheim tunneling model at a high bias voltage and recombined through these defect centers in SiO2 film.展开更多
Adsorption of single gold （Au） atom at three kinds of sites （hollow, bridge and top） on the hydroxylated β-cristobalite SiO2 （1 1 1） surface was studied using the first-principles calculations with general grad...Adsorption of single gold （Au） atom at three kinds of sites （hollow, bridge and top） on the hydroxylated β-cristobalite SiO2 （1 1 1） surface was studied using the first-principles calculations with general gradient approximation （GGA）. The results of adsorption energies and density of electronic states （DOS） suggest that the hollow and bridge sites have the basically equal capability of binding Au, while the ability of the Top site is weaker. Two new energy levels emerge after the adsorption at all sites; in DOS of the Hollow configuration, one locates at -0.15 eV, composed of Au 5d and O 2p electronic states, another just crosses through the Fermi level, consisting of Au 6s, H 1s and O 2p. In addition, Mulliken population analyses indicate that electron transfer takes place between the Au atom and the surface H and O atoms in the Hollow and Bridge configurations, which can be used to interpret the adsorption of Au onto the positions. However, neither H nor O chemically bonds with Au atom.展开更多
An effective surface enhanced Raman scattering（SERS） substrate is designed and fabricated by synthesis of Si O2 nanorods array via glancing angle deposition, followed by coating Au nanoparticles onto Si O2 surface i...An effective surface enhanced Raman scattering（SERS） substrate is designed and fabricated by synthesis of Si O2 nanorods array via glancing angle deposition, followed by coating Au nanoparticles onto Si O2 surface in order to create numerous ＂hot spots＂. The detecting sensitivity of such substrate could be optimized by simply adjusting the deposition time of Au. Thus, it can be used for detection of Rhodamine 6G at concentration as low as 10^-9M. Furthermore, our SERS substrate is applied to detect 5 μg/g polychlorinated biphenyls in soil sample, which proves its potential for trace environmental pollutants detection.展开更多
文摘The samples of Au/（Si/SiO2 ）/p-Si structure were fabricated by using the R. F magnetron sputtering technique. Its carrier transport and electroluminescence mechanism were studied from the Ⅰ-Ⅴ curves and EL spectra by using the Configuration Coordinate as a theoretical model. The result indicates that there are two defect centers in SiO2 films. The electron in Au and the hole in p-Si went into SiO2 film by the Fowler-Nordheim tunneling model at a high bias voltage and recombined through these defect centers in SiO2 film.
基金Funded by the Fundamental Research Funds for the Central Universities (No. CUGL100240)
文摘Adsorption of single gold （Au） atom at three kinds of sites （hollow, bridge and top） on the hydroxylated β-cristobalite SiO2 （1 1 1） surface was studied using the first-principles calculations with general gradient approximation （GGA）. The results of adsorption energies and density of electronic states （DOS） suggest that the hollow and bridge sites have the basically equal capability of binding Au, while the ability of the Top site is weaker. Two new energy levels emerge after the adsorption at all sites; in DOS of the Hollow configuration, one locates at -0.15 eV, composed of Au 5d and O 2p electronic states, another just crosses through the Fermi level, consisting of Au 6s, H 1s and O 2p. In addition, Mulliken population analyses indicate that electron transfer takes place between the Au atom and the surface H and O atoms in the Hollow and Bridge configurations, which can be used to interpret the adsorption of Au onto the positions. However, neither H nor O chemically bonds with Au atom.
基金supported by the National Basic Research Program of China(Grant No.2013CB934301)the National Natural Science Foundation of China(Grant No.50931002)+1 种基金the Research Project of Chinese Ministry of Education(Grant No.113007A)the Initiative Scientific Research Program of Tsinghua University,China
文摘An effective surface enhanced Raman scattering（SERS） substrate is designed and fabricated by synthesis of Si O2 nanorods array via glancing angle deposition, followed by coating Au nanoparticles onto Si O2 surface in order to create numerous ＂hot spots＂. The detecting sensitivity of such substrate could be optimized by simply adjusting the deposition time of Au. Thus, it can be used for detection of Rhodamine 6G at concentration as low as 10^-9M. Furthermore, our SERS substrate is applied to detect 5 μg/g polychlorinated biphenyls in soil sample, which proves its potential for trace environmental pollutants detection.
