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1.
Determination of the Geometric Structure of Core Excited Silane Based on Photoabsorption Spectra Near the Si 2p Edges
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The photoabsorption spectra near the Si 2p edges of SiH4 have been studied based on the multiple-scattering selfconsistent-field method.Our theoretical calculations provide clear assignments of the inner-shell photoabsorption spectra.In comparison with high-resolution experimental spectra,the geometric structure of the Si 2p excited SiH4^** is recommended as C2v symmetry. 相似文献
2.
The structure of Au/Si/SiO2/p-Si has been fabricated using the magnetron sputtering technique. It has a very good rectifying behaviour. Visible electroluminescence (EL) has been observed from the Au/Si/SiO2/p-Si structure at a forward bias of 5V or larger. A broad band with one peak around 650-660 nm appears in all the EL spectra of the structure. The effects of the thickness of the Si layer in the Si/SiO2 films and of the input electrical power on EL spectra are studied systematically. 相似文献
3.
利用LB技术,以二十碳酸作辅助成膜材料,在疏水处理的p-Si上分别制备了2,4,6,10和20层聚乙烯咔唑超分子膜。对这种体系的表面光电压谱研究结果表明,表面光电压随PVK膜层数的增加而增强,在紫外区增强较为明显。随着膜层数的增加,表面光电压有趋于饱和的趋势。膜对基底的敏化主要是由于PVK的光导电性引起的。 相似文献
4.
The deposition of a single Si adatom on the p(2×2) reconstructed Si(100) surface has been simulated by an empirical tight-binding method. Using the perfect and defective Si surfaces as the deposition substrates, the deposition energies are mapped out around the research areas. From the calculated energy plots, the binding sites and several possible diffusion paths are achieved. The introduced defects will make the deposition behaviour different from that on the perfect surface. 相似文献
5.
Electroluminescence(EL)is observed from the Au/Si-rich SiO2 film/p-Si diodes,in which the Si-rich SiO2 films are scroed deliberately by a diamond tip.The EL intensity of the scroed diode annelaed at 800℃ is about 6 times of that of the unscored counterpart,The EL sectrum of the usscored diode could be decomposed into two Gaussian luminescence bands with peaks at about 1.83 and 2.23eV,while for the EL spectrum of the scored diode,an additional Gaussian band at about 3.0eV appears,and the 1.83-eV peak increases significantly in intensity,The photoluminescence(PL) spectrum of an unscored Si-rich SiO2 film has only one band peaking at about 1.48eV,whereas the Pl spectrum of the scored one has two bands at about 1.48 and 1.97eV.We consider that the high-density defect regions produced by the scoring provide new luminescence centres and become some types of nonradiative centres in the Si oxide layer,which thus result in changes of the EL and PL spectra. 相似文献
6.
利用LB技术,以二十碳酸作辅助成膜材料,在疏水处理的P-Si上分别制备了2、4、6、10和20层聚乙烯咔唑(PVK)超分子膜。对这种体系的表面光电压谱(SPS)研究结果表明,表面光电压随PVK膜层数的增加而增强,在紫外区增强较为明显。随着膜层数的增加,表面光电压有趋于饱和的趋势。膜对基底的敏化主要是由于PVK的光导电性引起的。 相似文献
7.
Molecular Dynamics Simulation of Ion Implantation into HfO2 and HfO2/Si Multi-Layer Structure
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We simulate the B, As and P implantations into HfO2 from 3keY to 40keY by a simulator LEACS developed based on molecular dynamics method and by the traditional Monte Carlo simulator TSUPREM4 respectively. The LEACS results accurately fit with the SIMS (secondary ion mass spectroscopy) data, while the TSUPREM4 results deviate from the SIMS data obviously except B implantation. Based on the verification of the simulator, influence of the oxide thickness on the retained range profiles in the Si layer has been quantitatively investigated in the case of HfO2/Si and SiO2/Si structures. The range profiles in the Si layer through HfO2 shift to the surface obviously for about 0.68 times of the oxide layer thickness on the average in comparison to those through SiO2. It can be predicted that this effect will have a significant impact on MOSFET (metallic oxide semiconductor field effect transistor) device performance in the integrated circuit process of the next decade if HfO2 is used to replace SiO2 as the gate dielectric. 相似文献
8.
S.-K. Wang W.-C. Tsai L.-C. Chou J. Chen Y.-H. Wu T.-M. He K.-S. Feng C.-R. Wen 《Surface science》2012,606(13-14):1062-1070
Continuous-time photoelectron spectroscopy (PES) and continuous-time core-level photon-stimulated desorption (PSD) spectroscopy were used to study the monochromatic soft X-ray-induced reactions of CCl2F2 molecules adsorbed on Si(111)-7 × 7 at 30 K (CCl2F2 dose = 2.0 × 1014 molecules/cm2, ~ 0.75 monolayer) near the Si(2p) core level. Evolution of adsorbed CCl2F2 molecules was monitored by using continuous-time photoelectron spectroscopy at two photon energies of 98 and 120 eV to deduce the photolysis cross section as a function of energy. It was found that the photolysis cross sections for 98 and 120 eV photons are ~1.4 × 10? 18 and ~ 8.0 × 10? 18 cm2, respectively. Sequential F+ PSD spectra obtained by using continuous-time core-level photon-stimulated desorption spectroscopy in the photon energy range of 98–110 eV show the variation of their shapes with photon exposure and depict the formation of surface SiF species. The dissociation of CCl2F2 molecules adsorbed on Si(111)-7 × 7, irradiated by monochromatic soft X-ray in the photon energy range of 98–110 eV, is mainly due to dissociative electron attachment and indirect dipolar dissociation induced by photoelectrons emitted from the silicon surface. 相似文献
9.
The excitation functions of the29Si(d, p)30Si reaction in the deuteron energy range of 1·1–2·1 MeV have been measured in steps of 9.3 keV at angles 40°, 60°, 90°, 100°, 110°, 130° and 150° for the following groups of protons: po (g.s. of the30Si nucleus), p1 (2·23 MeV), p2 (3·51 MeV), p3,4 (3·77 and 3·79 MeV), p5,6 (4·81 and 4·83 MeV), p10 (5·48 MeV) and pn (5.61 MeV). Within the framework of Ericson's theory of statistical fluctuations the autocorrelations, cross-angle correlations and cross-group correlations have been calculated and the mean coherence width of the31P compound nucleus has been deduced to be 27 keV.The authors would like to express their thanks to K. Putz for the efficient performance of the electronical equipment and to the staff of the Van de Graaff laboratory for operating the accelerator. 相似文献
10.
A New Model Potential Acting on the Excited Electron Within Molecules: Application to Calculate the Recurrence Spectra of Excited H2 Molecules in Strong External Fields
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WANGDe-Hua DINGShi-Liang 《中国物理快报》2004,21(7):1191-1194
By using the molecular orbit theory, we give a new model potential acting on the excited electron within a molecule. The potential is the total interaction energy of this electron with all the nuclei and other electrons.We find that the introduction of a new model potential results in an extreme increase of the number of closed orbits as compared to the hydrogen atom. Making use of the molecular closed-orbit theory (MCOT) and the new model potential, we calculate the recurrence spectra of H2 molecules in parallel electric and magnetic fields for different quantum defects. The modulations in the spectra can be analysed in terms of the scattering of the excited electron on the molecular core. Our results are in good agreement with the quantum results. 相似文献
11.
The bond length of ^4HeH^+ resulting from collision-induced destruction is measured at 1.4420 MeV using the Coulomb Explosion Technique. The measured bond length of ^4HeH^+ is 0.094±0.003nm. The bond length of ^4HeH^+ obtained with our radio frequency (RF) ion source is larger than that obtained with a duoplasmatron ion source at Argonne National Laboratory (ANL), but the bond lengths of H^+2 and H^+3obtained separately by ANL and by us with the two different ion sources are consistent with each other, which implies that there exists an ion source effect on the bond length of ^4HeH^+. The main reason why the 4^4HeH^+ bond lengths obtained by the two different ion sources are different is also discussed. 相似文献
12.
C. Karras C. M��hlig W. Paa T. Zeuner W. Triebel H. Stafast 《Applied physics. B, Lasers and optics》2011,104(1):17-20
Femtosecond (fs) laser pulses at variable delay times allowed us to track the fast non-radiative transitions between the manifold of highly excited $\mathrm{M}_{\mathrm{Na}}^{**}$ states to the lower lying fluorescent $\mathrm{M}_{\mathrm{Na}}^{*}$ state in CaF2. Two distinct $\mathrm{M}_{\mathrm{Na}}^{**}$ states of the manifold at 3.16?eV ( $\mathrm{M}_{\mathrm{Na}2}^{**}$ ) and 4.73?eV ( $\mathrm{M}_{\mathrm{Na}3}^{**}$ ) were populated using the second (SH) and third harmonics (TH) of fs laser light at 785?nm. The population kinetics of the fluorescent $\mathrm{M}_{\mathrm{Na}}^{*}$ state in the 2?eV excitation energy range was revealed by depleting its fluorescence centered at 740?nm using fundamental near infrared (NIR) fs laser pulses. The related time constants for $\mathrm{M}_{\mathrm{Na}2,3}^{**}{\sim}{>} \mathrm{M}_{\mathrm{Na}}^{*}$ relaxation amounted to 1.0±0.14?ps and 3.0±0.3?ps upon SH and TH excitation, respectively. 相似文献
13.
New class of layered oxides, phyllosiloxides, was expanded to three new compositions: KMg 2 Fe 3+ Si 4 O 12 , \rm{KFe}^{2+}_{2}\rm{AlSi}_{4}\rm{O}_{12} , and \rm{KFe}^{2+}\rm{Fe}^{3+}_{3}\rm{Si}_{3}\rm{O}_{12} . The sol-gel route was adopted to prepare a precursor and the polycrystalline samples were obtained by solvothermal treatments at 750 °C/160 MPa using 2-methoxy ethanol as solvent. The three powder X-ray diffraction patterns were successfully indexed by 1 M polytype of mica. Platelet morphologies of these samples were observed through the images of scanning electron microscopy. 相似文献
14.
Heloisa Maria Boechat-Roberty Elmar O. Uhl Flavio N. Rodrigues Maria Cristina A. Lopes Maria Luiza M. Rocco Carlos A. Lucas Alexandre B. Rocha Carlos E. Bielschowsky Gerardo Gerson B. de Souza 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2013,67(2):1-6
Electron energy-loss spectra for the butadiene molecule were measured in the scattering angular range of 2.0° to 8.0°, in an energy-loss range from 2 to 50 eV, using 1000 eV incident electrons. The absolute generalized oscillator strength (GOS) and inelastic cross section have been determined for the \hbox{$\tilde{\rm X}^{1}$}?X1A g → 11B u transition. The absolute elastic differential cross section was also determined spanning an angular range from 2.0° to 40.0°. From a small angle electron energy-loss spectrum, the optical oscillator distribution (photoabsorption spectrum) for the butadiene molecule was obtained in the 2 to 100 eV photon energy range. Accurate ab initio calculations have been performed, within the First Born Approximation, for generalized oscillator strength (GOS) and excitation energies for the \hbox{$\tilde{\rm X}^{1}$}?X1A g → 11B u and \hbox{$\tilde{\rm X}^{1}$}?X1A g → 21A g transitions. Our results emphasize the importance of using highly correlated wavefunctions and accurate methodologies in the calculation of the GOS for electron impact-induced electronic transitions in molecules. 相似文献
15.
The spin Hamiltonian parameters (SHPs) (g factors and hyperfine structure constants) for the mononuclear square pyramidal [CuO5] groups in two paddle wheel copper complexes {Cu2(μ2–O2CCH3)4}(OCNH2CH3) and \({}_{\infty }^{3} [{\text{Cu}}_{ 2}^{\text{I}} {\text{Cu}}_{ 2}^{\text{II}} ( {\text{H}}_{ 2} {\text{O)}}_{ 2} {\text{L}}_{ 2} {\text{Cl}}_{ 2} ]\) are theoretically investigated from the perturbation calculations of these parameters for a rhombically elongated octahedral 3d 9 group. The slightly larger anisotropy Δg (≈ g // ? g⊥) of complex 1 than complex 2 is attributed to the slightly bigger deviations of the polar angles related to the ideal value 90° and relative differences between the axial and basal Cu–O distances in the former. The axiality of the EPR signals for both systems can be illustrated as the fact that the perpendicular anisotropic contributions to X and Y components of the SHPs arising from the four basal ligands with slightly distinct bond lengths and bond angles may roughly cancel one another. The signs of hyperfine structure constants are also theoretically determined for both complexes. 相似文献
16.
Li Lu Takashi Nishida Masahiro Echizen Yasuaki Ishikawa Kiyoshi Uchiyama Yukiharu Uraoka 《Applied Physics A: Materials Science & Processing》2013,112(2):425-430
Sol–gel-derived SrTa2O6 thin films were fabricated at a low temperature of 500 °C. To improve their leakage current properties, additional UV/O3-assisted annealing was performed from room temperature to 290 °C. UV/O3 treatment at 290 °C gave a very low leakage current that was six orders of magnitude lower than that of an untreated thin film. During UV/O3-assisted annealing, Si and Ti ions diffused from the substrates into the SrTa2O6 thin films and occupied the Ta5+ sites, subsequently generating Si? and Ti?. At a heating temperature of 290 °C, large amounts of Ti ions diffused throughout the SrTa2O6 thin film. These Ti ions contributed to the generation of inactive combinations of $(\mathrm{Si}^{-}\mbox{--}\mathrm{V}_{\mathrm{o}}^{+})^{+}\mbox{--}\mathrm{Ti}^{-}$ and $(\mathrm{Ti}^{-}\mbox{--}\mathrm{V}_{\mathrm{o}}^{+})^{+}\mbox{--}\mathrm{Ti}^{-}$ , which greatly reduced oxygen vacancies (Vo). Thus, the leakage current was significantly reduced. 相似文献
17.
《Surface science》1987,179(1):L71-L76
Well ordered Rh overlayers have been grown on Si tip surfaces in ultrahigh vacuum. The field ion images of the overlayers grown on the Si{012} plane reveal two distinctive atomic structures. One has a diamond structure with an angle of 76° ± 2° and one has a rhombic structure with an angle of 66° + 2°. The former fits well to the atomic structure of the Rh layer of the RhSi(110) plane and the latter fits well to the structure of the Si(012) plane. 相似文献
18.
This paper studies the isotopic effect of Cl2+ rovibronic spectra in the A2Πu(Ω=1/2) X 2Πg(Ω= 1/2) system.Based on the experimental results of the molecular constants of 35 Cl2+,it calculates the vibrational isotope shifts of the(2,7) and(3,7) band between the isotopic species 35 Cl+2,35 Cl 37 Cl+and 37 Cl2+,and estimates the rotational constants of both A 2 Π u and X 2 Π g states for the minor isotopic species 35 Cl 37 Cl+and 37 Cl2+.The experimental results of the spectrum of 35 Cl 37 Cl+(3,7) band proves the above mentioned theoretical calculation.The molecular constants and thus resultant rovibronic spectrum for 37 Cl2+ were predicted,which will be helpful for further experimental investigation. 相似文献
19.
G. S. Joyce 《Journal of statistical physics》1990,58(3-4):443-465
The properties of the high-field polynomialsL n (u) for the one-dimensional spin 1/2 Ising model are investigated. [The polynomialsL n (u) are essentially lattice gas analogues of the Mayer cluster integralsb n (T) for a continuum gas.] It is shown thatu ?1 L n (u) can be expressed in terms of a shifted Jacobi polynomial of degreen?1. From this result it follows thatu ?1 L n (u); n=1, 2,... is a set of orthogonal polynomials in the interval (0, 1) with a weight functionω(u)=u, andu ?1 L n (u) hasn?1 simple zerosu n (v); v=1, 2,...,n?1 which all lie in the interval 0<u<1. Next the detailed behavior ofL n (u) asn→∞ is studied. In particular, various asymptotic expansions forL n (u) are derived which areuniformly valid in the intervalsu<0, 0<u<1, andu>1. These expansions are then used to analyze the asymptotic properties of the zeros {u n (v); v=1, 2,...,n?1}. It is found that $$\begin{array}{*{20}c} {u_n (v) \sim \tfrac{1}{4}({{j_{1,v} } \mathord{\left/ {\vphantom {{j_{1,v} } n}} \right. \kern-\nulldelimiterspace} n})^2 [1 - ({{j_{1,v}^2 } \mathord{\left/ {\vphantom {{j_{1,v}^2 } {12}}} \right. \kern-\nulldelimiterspace} {12}})n^{ - 1} + ({{j_{1,v}^2 } \mathord{\left/ {\vphantom {{j_{1,v}^2 } {700)( - 3 + 2j_{1,v}^2 )n^{ - 4} }}} \right. \kern-\nulldelimiterspace} {700)( - 3 + 2j_{1,v}^2 )n^{ - 4} }}} \\ { + ({{j_{1,v}^2 } \mathord{\left/ {\vphantom {{j_{1,v}^2 } {20160)(40 + 4j_{1,v}^2 - j_{1,v}^4 }}} \right. \kern-\nulldelimiterspace} {20160)(40 + 4j_{1,v}^2 - j_{1,v}^4 }})n^{ - 6} + \cdot \cdot \cdot ]} \\ {u_n (n - v) \sim 1 - ({{j_{0,v}^2 } \mathord{\left/ {\vphantom {{j_{0,v}^2 } 4}} \right. \kern-\nulldelimiterspace} 4})n^{ - 2} + ({{j_{0,v}^2 } \mathord{\left/ {\vphantom {{j_{0,v}^2 } {48)( - 2 + j_{0,v}^2 )n^{ - 4} }}} \right. \kern-\nulldelimiterspace} {48)( - 2 + j_{0,v}^2 )n^{ - 4} }}} \\ { + ({{j_{0,v}^2 } \mathord{\left/ {\vphantom {{j_{0,v}^2 } {2880)(2 + 9j_{0,v}^2 - 2j_{0,v}^4 )n^{ - 6} + \cdot \cdot \cdot }}} \right. \kern-\nulldelimiterspace} {2880)(2 + 9j_{0,v}^2 - 2j_{0,v}^4 )n^{ - 6} + \cdot \cdot \cdot }}} \\ \end{array} $$ asn→∞v fixed, wherej k,v denotes thevth zero of the Bessel functionJ k(z) 相似文献
20.
Based on the beyond-mean-field Skyrme–Hartree–Fock model, impurity effects of the Λhyperon in the hypernuclear systems ${}_{\,{\rm{\Lambda }}}^{25}$ Mg and ${}_{\,{\rm{\Lambda }}}^{29}$ Si are investigated, respectively. Four cases, in which the Λhyperon occupies the single-particle orbitals ${\rm{\Lambda }}$[000]${\tfrac{1}{2}}^{+}$, ${\rm{\Lambda }}$[110]${\tfrac{1}{2}}^{-}$, ${\rm{\Lambda }}$[101]${\tfrac{3}{2}}^{-}$ and ${\rm{\Lambda }}$[101]${\tfrac{1}{2}}^{-}$, are focused. In each case, the potential energy surface and the energy curves projected on certain angular momenta are employed to show the influence of the Λhyperon on the nuclear core. Beside the shrinkage effect that is induced by the Λhyperon occupying the sΛ orbital, it is found that the Λhyperon on the pΛ orbital, ${\rm{\Lambda }}$[110]${\tfrac{1}{2}}^{-}$, drives the nuclear core toward a prolate shape, while the ones on the other two pΛ orbitals, ${\rm{\Lambda }}$[101]${\tfrac{3}{2}}^{-}$ and ${\rm{\Lambda }}$[101]${\tfrac{1}{2}}^{-}$, drive the nuclear core toward an oblate shape. The energy spectra and the corresponding intra-band E2 transition rates for the rotational bands are given as a prediction for future experiments. 相似文献