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Dependency of photoluminescence from SiO2 thin films containing Si1-xGex quantum dots on Ge/Si doping ratio

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Chinese Optics Letters 2009年第9期7卷 826-829页

作者：仲坤肖志松程国安程向前郑瑞廷 key laboratory of beam technology and material modification of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal University department of physics School of ScienceBeihang University

SiO2 thin films containing Si1-xGex quantum dots （QDs） are prepared by ion implantation and annealing treatment. The photoluminescence （PL） and microstructural properties of thin films are investigated. The samples exhibit strong PL in the wavelength range of 400-470 nm and relatively weak PL peaks at 730 and 780 nm at room temperature. Blue shift is found for the 400-nm PL peak, and the intensity increases initially and then decreases with the increase of Ge-doping dose. We propose that the 400-470 nm PL band originates from multiple luminescence centers, and the 730- and 780-nm PL peaks are ascribed to the Si=O and GeO luminescence centers.

关键词： Germanium Ion bombardment Ion implantation Light emission Photoluminescence Semiconductor quantum dots Silicon Thin films

First-Principles Band Calculations on Electronic Structures of Ag-Doped Rutile and Anatase TiO2

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Chinese physics Letters 2009年第7期26卷 270-273页

作者：侯兴刚刘安东黄美东廖斌吴晓玲 department of physics Tianjin Normal University Tianjin 300387 key laboratory of beam technology and material modification of Ministry of Education Beijing Normal University Beijing 100875

The electronic structures of Ag-doped rutile and anatase Ti02 are studied by first-principles band calculations based on density functional theory with the full-potential linearized-augmented-plane-wave method. New occupied bands are found between the band gaps of both Ag-doped rutile and anatase TiO2. The formation of these new bands can be explained mainly by their orbitals of Ag 4d states mixed with Ti 3d states and are supposed to contribute to their visible light absorption.

关键词： VISIBLE-LIGHT IRRADIATION NEGATIVE-ION IMPLANTATION TITANIUM-DIOXIDE PHOTOCATALYSTS FILM

Structural and Raman Analysis of Antimony-Implanted ZnMnO Films

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Plasma Science and technology 2010年第1期12卷 92-94页

作者：柯贤文单福凯王广甫刘传胜付德君 Accelerator laboratory Department of Physics and Department of Printing and PackagingWuhan University Growing Base for State key laboratory Qingdao University key laboratory of beam technology and material modification of Ministry of Education Beijing Normal University

Antimony ions were implanted into ZnMnO films grown on silicon （Si） by radio- frequency magnetron sputtering. The implanted samples were treated by rapid thermal annealing and investigated by X-ray photoelectron spectroscopy, X-ray diffraction and Raman scattering. In the wurtzite of ZnMnO, both manganese （Mn） and stibium （Sb） substituted the lattice position of zinc （Zn）. The ZnMnO films were characterized by Raman scattering at 522 cm-1, attributed to a local vibration of Mn. After implantation with Sb ions, two new peaks 681 cm^-1 and 823 cm^-1 were observed in the ZnMnO films, as a result of ion-induced damage to the lattice.

关键词： Sb ion implantation ZnMnO structure Raman scattering

Quantum Dissipative Threshold and Its Effect on Decay of Metastable State

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Communications in Theoretical physics 2005年第4X期44卷 697-700页

作者： BAO Jing-Dong The key laboratory of beam technology and material modification of Ministry of Education Beijing Normal UniversityBeijing 100875 ChinaThe Key Laboratory of Beam Technology and Material Modification of Ministry of Education Beijing Normal UniversityBeijing 100875 China department of physics Beijing Normal University Beijing 100875 China

The coupling between system and reservoir is considered to be linear in the coordinates of the bath but nonlinear in the system's coordinate. A dissipative threshold is observed at finite temperatures due to nonlinear dissipation. The quantum decay rate of a metastable state including higher-order expanded terms of the coupling form function is proposed, which can be strongly decreased at finite temperatures when the quantum dissipative threshold is added to the saddle point of the potential.

关键词： threshold decay rate nonlinear dissipation quantum correction factor

Incommensurate Antiferromagnetism in the Extended t-J Model

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Communications in Theoretical physics 2002年第5期38卷 617-620页

作者： LIANG Ying MA Tian-Xing FENG Shi-Ping CHEN Wei-Yeu department of physics and key laboratory of beam technology and material modification Beijing Normal University Beijing 100875 China National laboratory of Superconductivity Academia Sinica Beijing 100080 China Department of Physics and Key Laboratory of Beam Technology and Material Modification Beijing Normal University Beijing 100875 China National laboratory of Superconductivity Academia Sinica Beijing 100080 China Department of Physics and Key Laboratory of Beam Technology and Material Modification Beijing Normal University Beijing 100875 China National laboratory of Superconductivity Academia Sinica Beijing 100080 China Department of Physics Tamkang University Tamsui 25137 Taiwan

The effect of the extra second neighbor hopping t' on the incommensurate spin correlation in the t-J modelin the underdoped regime is studied within the fermion-spin theory. It is shown that although the extra second neighborhopping t' is systematically accompanied with the increasing of the weight of the incommensurate peaks in the dynamicalspin structure factor, for the physical reasonable small value of t' the qualitative behavior of the incommensurate spincorrelation in the t-t'-J model is the same as in the case of t-J model.

关键词： incommensurate antiferromagnetism, t-J model, fermion-spin theory

Microstructure and mechanical properties of TiN/AlN multilayers deposited by filtered vacuum arc deposition

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 234-237页

作者： ZHANG Xu ZHANG Hui-xing ZHANG Tong-he WU Xian-ying key laboratory of beam technology and material modification of Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal UniversityBeijing Radiation Center Beijing 100875 China Key Laboratory of Beam Technology and Material Modification of Ministry of EducationInstitute of Low Energy Nuclear Physics Beijing Normal UniversityBeijing Radiation Center Beijing 100875 China Key Laboratory of Beam Technology and Material Modification of Ministry of EducationInstitute of Low Energy Nuclear Physics Beijing Normal UniversityBeijing Radiation Center Beijing 100875 China Key Laboratory of Beam Technology and Material Modification of Ministry of EducationInstitute of Low Energy Nuclear Physics Beijing Normal UniversityBeijing Radiation Center Beijing 100875 China

Nanometer TiN/AlN multilayers were prepared on silicon substrate by filtered vacuum arc *** structures of the nanometer TiN/AlN multilayer were studied by using X-ray diffraction. The 12 nm TiN/AlN multiplayer is composed of cubic TiN structure and hexagonal wurzite AlN structure, but the 2 nm period multilayer is composed of face centered cubic structure TiN and AlN with strong (200) texture. The surface roughness, hardness and elastic modulus of multilayer are dependent on the period of multilayer. The hardness of the TiN/AlN multilayers is higher than that suggested by a simple rule of mixture. The peaking hardness of nanometer TiN/AlN multilayers at period of 2 nm is about 42 GPa, much higher than that of 12 nm. The wear resistance of the nanometer TiN/AlN multilayers was also studied.

关键词： multilayer filtered arc nanometer wear

Simulations and Measurement of Electron Energy and Effective Electron Temperature of Nanosecond Pulsed Argon Plasma

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Plasma Science and technology 2012年第1期14卷 40-47页

作者： WEN Xueqing XIN Yu FENG Chunlei DING Hongbin School of physics and Optical Electronic technology Key Laboratory of Material Modification by LaserIon and Electron BeamChinese Ministry of EducationDalian University of Technology116023 DalianChina

The behavior of argon plasma driven by nanosecond pulsed plasma in a low-pressure plasma reactor is investigated using a global model, and the results are compared with the experimental measurements. The time evolution of plasma density and the electron energy probability function are calculated by solving the energy balance and Boltzmann equations. During and shortly after the discharge pulse, the electron energy probability function can be represented by a bi-Maxwellian distribution, indicating two energy groups of electrons. According to the effective electron temperature calculation, we find that there are more high-energy electrons that play an important role in the excitation and ionization processes than low-energy electrons. The effective electron temperature is also measured via optical emission spectroscopy to evaluate the simulation model. In the comparison, the simulation results are found to be in agreement with the measure- ments. Furthermore, variations of the effective electron temperature are presented versus other discharge parameters, such as pulse width time, pulse rise time and gas pressure.

关键词： effective electron temperature model optical emission spectrum nanosecond pulsed glow discharge global

Simulation of x-ray transmission through an ellipsoidal capillary

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Chinese physics B 2010年第7期19卷 40-44页

作者：林晓燕李玉德孙天希潘秋丽 The key laboratory of beam technology and material modification of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal University Beijing Radiation Center

This paper develops a simulation program for x-ray transmission in an ellipsoidal capillary based on a ray-tracing method. The influence of the parameters of ellipsoidal capillary and x-ray energy on transmission efficiency, full width at half maximum and power density gain of x-ray beams through an ellipsoidal capillary was analysed by this program. It shows that the particular rules of the ellipsoidai capillary x-ray lens are different from the polycapillary lens. Furthermore, this analysis method can be applied to the optimized design of ellipsoidal capillary.

关键词： ellipsoidal capillary transmission efficiency power density gain simulation

Measurement of inner surface roughness of capillary by an x-ray reflectivity method

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Chinese physics B 2011年第4期20卷 217-221页

作者：李玉德林晓燕谭植元孙天希刘志国 The key laboratory of beam technology and material modification of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing Radiation Center

The inner surface roughness of a capillary is investigated by the reflectivity of x-rays penetrating through the capillary. The results are consistent with the data from atomic force microscope （AFM）. The roughness ... 详细信息

关键词： inner surface roughness reflectivity method capillary