共查询到10条相似文献,搜索用时 93 毫秒
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The electronic valence band structures of polymerized thin films of C60 and La0.1C60 have been studied by using ultra-violet photoelectron spectroscopy. Additionally, the films have been characterized by using Raman spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The valence band of the C60 film shows major peaks at binding energies of 2.6, 7.2, 10.3, and 12.6 eV. In the case of the doped film, we observe (i) an additional peak with a binding energy of 13.7 eV, (ii) evidence for redistribution of the density of electronic states due to hybridization between the 5d orbitals of La and the C60 cage, and (iii) significantly higher density of the electronic states near the Fermi energy. The valence band spectra of the doped film are in good agreement with recent results of the density functional theory that support strong hybridization between the d-valence orbitals of La and the C60 cage. 相似文献
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采用离子注入技术对近距离升华制备的CdTe薄膜进行Er3+掺杂研究.讨论了不同掺Er3+浓度对CdTe薄膜的结构和光电性能的影响.利用X射线衍射仪、扫描电子显微镜、紫外-可见分光光度计、霍耳效应测试系统和复阻抗分析仪对样品进行测试.结果表明,适当的掺杂量可以改善CdTe薄膜的结晶性能,降低晶界势垒高度,提高其导电性能.在一定掺杂范围内掺Er3+对CdTe薄膜的光能隙影响不大.
关键词:
CdTe薄膜
离子注入
晶界势垒
光能隙 相似文献
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Shuangxi Wang 《中国物理 B》2022,31(4):47105-047105
First-principles calculations based on the density functional theory were performed to systematically study the electronic properties of the thin film of antimony in (111) orientation. By considering the spin-orbit interaction, for stoichiometric surface, the topological states keep robust for six-bilayer case, and can be recovered in the three-bilayer film, which are guaranteed by time-reversal symmetry and inverse symmetry. For reduced surface doped by non-magnetic Bi or magnetic Mn atom, localized three-fold symmetric features can be identified. Moreover, band structures show that the non-trivial topological states stand for non-magnetic substitutional Bi atom, while can be eliminated by adsorbed or substitutional magnetic Mn atom. 相似文献
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M. Alaoui Lamrani Z. Sofiani B. Sahraoui A. El Hichou J.C. Bernède 《Optics Communications》2007,277(1):196-201
We have deposited zinc oxide (ZnO) and erbium doped zinc oxide (ZnO:Er) thin films on heated glass substrates using spray pyrolysis technique. The effect of erbium dopant on structural, morphological, luminescent and nonlinear optical properties was studied. The deposited films have been analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), ex situ compositional analysis (ESCA), profilometry, cathodoluminescence (CL) and third harmonic generation (THG) measurements. All films were polycrystalline, having a preferential growth orientation along the ZnO (0 0 2) plane, with a corresponding average crystallite size of less than 41 nm. Addition of erbium can effectively control the film surface morphology and its cathodoluminescent properties. The films containing low erbium concentration show a uniform surface covered with hexagonal shaped grains and a strong UV light emission intensity as well as TH response. In contrast, when the erbium doping ratio exceeds 3%, a porous surface with columnar textural growth becomes more pronounced, and a substantial reduction of the cathodoluminescent and TH response. A strong TH signal was obtained for the film with good crystalline quality at the concentration of 2%. Third order nonlinear optical susceptibility (χ〈3〉) values of the studied materials were in the remarkable range of 10−12 esu. 相似文献
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G. Schlaghecken J. Gottmann E.W. Kreutz R. Poprawe 《Applied Physics A: Materials Science & Processing》2004,79(4-6):1255-1257
Laser radiation is used for the deposition of dielectric erbium doped BaTiO3 thin films for photonic applications. Pulsed laser deposition with KrF excimer laser radiation (wavelength 248 nm, pulse duration 20 ns) is used to grow dense, transparent, amorphous, poly-crystalline and single crystalline erbium doped BaTiO3 thin films. Visible emission due to up-conversion luminescence (wavelength 528 nm and 548 nm) under excitation with diode laser radiation at a wavelength of 970–985 nm is investigated as a function of the erbium concentration of 1–20 mol% and structural film properties. PACS 81.15.Fg; 42.55.Wd; 68.55; 78.55.Hx 相似文献
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This paper reports on the formation of unique micrometer-scale clusters in erbium-doped silicon-rich silicon oxide (ErSRSO) thin films produced by thermal evaporation. Through scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), we identify these micro-clusters as structures where the film curves away from the substrate to encase erbium-rich aggregates. Even though erbium aggregation has been reported to cause quenching, we demonstrate that the micro-clusters as a whole can exhibit significantly enhanced erbium photoluminescence (PL), with emissions over 24 times brighter than the surrounding non-cluster region. Mapping micro-photoluminescence measurements onto SEM images reveals that the erbium aggregates alone do not generate the enhanced PL, but rather the thin film encasing the aggregates is the origin of the emissions. Analysis of the PL Stark splitting shows a correlation between the micro-clusters’ fine structure and the strength of their PL. Taken together, the above evidence indicates that the micro-clusters’ strong PL is produced by changes in the local environment of the Er3+ inside the thin film surrounding the erbium-rich aggregates. 相似文献
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The γ phase of the erbium-hydrogen system is a hexagonal trihydride that is not predicted to be stable at room temperature without an overpressure of hydrogen gas. Herein, we report the creation of both, a thin film and powder of erbium trihydride that is metastable at ambient conditions. The presence of the hexagonal γ phase was determined by X-ray diffraction (XRD). The ratio of the total moles of hydrogen isotopes (hydrogen and deuterium) to moles of erbium, (H + D):Er, have been confirmed by elastic recoil detection (ERD)/Rutherford backscattering spectroscopy (RBS). Auger electron spectroscopy (AES) depth profiles and X-ray photoelectron spectroscopy (XPS) revealed the presence of an oxide layer that may account for the metastable behavior of the thin film. 相似文献
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The magnetic and transport behaviors of manganites are critically related to the spatial distribution and correlation of doped holes. Using in situ scanning tunneling microscopy, we have imaged both occupied and unoccupied states simultaneously in a hole-doped (La(5/8-0.3)Pr0.3)Ca(3/8)MnO3 epitaxial thin film grown by laser molecular beam epitaxy. Doped holes localized on Mn4+ ion sites were directly observed with atomic resolution in the paramagnetic state at room temperature. In contrast to a random distribution, these doped holes show strong short-range correlation and clear preference of forming nanoscale CE-type charge-order-like clusters. The results provide direct visualization of the nature of intriguing electronic inhomogeneity in transition metal oxides. 相似文献