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Dye-sensitized solar cells: Atomic scale investigation of interface structure and dynamics

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chinese physics B 2014年第8期23卷 2-12页

作者：马薇张帆孟胜 Beijing national laboratory for condensed {3. physics and institute of physics Chinese Academy of Sciences Collaborative Innovation Center of Quantum matter

Recent progress in dye-sensitized solar cells （DSC） research is reviewed, focusing on atomic-scale investigations of the interface electronic structures and dynamical processes, including the structure of dye adsorption onto Ti02, ultrafast electron injection, hot-electron injection, multiple-exciton generation, and electron-hole recombination. Advanced exper- imental techniques and theoretical approaches are briefly summarized, and then progressive achievements in photovoltaic device optimization based on insights from atomic scale investigations are introduced. Finally, some challenges and oppor- tunities for further improvement of dye solar cells are presented.

关键词： dye-sensitized solar cells interface structure absorption electron injection multiple-exciton generation charge recombination

Band gap anomaly and topological properties in lead chalcogenides

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chinese physics B 2016年第3期25卷 27-34页

作者：聂思敏许霄琰徐刚方忠 Beijing national laboratory for condensed {3. physics and Institute of Physics Chinese Academy of Sciences Beijing 1O0190 China Collaborative Innovation Center of Quantum matter Beijing 100084 China

Band gap anomaly is a well-known issue in lead chalcogenides PbX （X = S, Se, Te, Po）. Combining ab initio calculations and tight-binding （TB） method, we have studied the band evolution in PbX, and found that the band gap anomaly in PbTe is mainly related to the high on-site energy of Te 5s orbital and the large s-p hopping originated from the irregular extended distribution of Te 5s electrons. Furthermore, our calculations show that PbPo is an indirect band gap （6.5 meV） semiconductor with band inversion at L point, which clearly indicates that PbPo is a topological crystalline insulator （TCI）. The calculated mirror Chern number and surface states double confirm this conclusion.

关键词： band gap anomaly lead chalcogenides indirect band gap semiconductor topological crystallineinsulator

Research progress in the inner surface modification of metal tubes by plasma processing

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Progress in natural Science:Materials International 2006年第11期16卷 1119-1126页

作者： ZHANG Guling~ 1,2 **, WU Xingfang~1, GU Weichao~2, CHEN Guangliang~2, FENG Wenran~2, NIU Erwu~2, LI Li~2, L Guohua~2, CHEN Huan~2, FAN Songhua~2, LIU Chizi~2 and YANG Size~2(1. School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083. china 2. Beijing national laboratory for {3. matter physics, institute of physics, chinese academy of sciences, Beijing 100080, china) School of Material Science and Engineering University of Science and Technology Beijing Beijing 100083 China Beijing national laboratory for condensed {3. physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

The recent progress in inner surface hardening of tubes by plasma processing is summerized. Several techniques of inner surface plasma source ion implantation and deposition are introduced, and their advantages and disadvantages are discussed. The basic principles, technical features and new progress of inner surface plasma source ion implantation methods for metal tubes, which were developed in our laboratory, are described in detail. And perspectives of the future technical development for inner surface ion implantation of tubes are presented.

关键词： PSII metal tubes inner surface surface modification.

Studies of Structure Evolution of nanostructured Hf_(11)Ni_(89) Alloy

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Journal of Materials Science & Technology 1998年第3期14卷 205-210页

作者： Zhenfu DONG and Lianmao PENG(Beijing Lab. of Electron Microscopy, institute of physics and Center for condensed matter {3.,chinese academy of sciences, P.O.Box 2724, Beijing 100080, china)Ke LU and Zhuangqi HU(State Key Lab. for RSA, institute of Meta Beijing Lab. of Electron Microscopy Institute of Physics and Center for Condensed Matter Physics Chinese Academy of Sciences P.O.Box 2724 Beijing 100080 China State Key Lab. for RSA Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

A nanostructured Hf11Ni89 ribbon sample was prepared by melt-spinning. It was found that the as-quenched sample is composed of a major HfNi5 compound nanophase and an interfacial magnetic Ni(Hf) solid solution phase. The structure evolution of the sample was studied by using X-ray difFraction (XRD), transmission electron microscopy (TEM), difFerential scanning calorimetry (DSC), resistivity and magnetothermal analysis. Upon heating, a second precipitation process of the Ni(Hf) phase prior to grain growth wa5 detected by means of both structural analysis and physical property measurements. The measurement results are discussed based on the relationship between microstructure and physical properties.

关键词： Studies of Structure Evolution of nanostructured Hf Alloy Ni

PHASE EXTENSION AND STRUCTURE AnaLYSIS BY THE MAXIMUM ENTROPY METHOD

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Acta Metallurgica Sinica(English Letters) 1998年第4期11卷 241-254页

作者： G.B.Hu and Q.B.Yang (Department of physics, Xiangtan University, Xiangtan 411105, china)(Beijing laboratory of Electron Microscopy, Center for {3. matter physics, The chinese academy of sciences, P. O. Box 2724, Beijing 100080, china) Xiangtan Univ Xiangtan China

Excellent results are obtained in structure analysis with jew phases of structure factors by the maximum-entropy method (MEM) for CaGaN PbCO3.and ReBe22 single crystals. The computation time and memory space are minim... 详细信息

关键词： maximum entropy method structure analysis phase extension,symmetry

Quantum phase transitions of fermionic atoms in an anisotropic triangular optical lattice

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chinese physics B 2013年第11期22卷 216-221页

作者：保安陈耀桦章晓中 laboratory of Advanced Materials School of Materials Science and Engineering Tsinghua University Beijing national laboratory for condensed {3. physics Institute of Physics Chinese Academy of Sciences

The effect of anisotropy caused by a confining potential on the properties of fermionic cold atoms in a triangular optical lattice is systematically investigated by using the dynamical cluster approximation combined with the continuous time quantum Monte-Carlo algorithm. The quantum phase diagrams which reflect the temperature-interaction relation and the competition between the anisotropic parameter and the interaction are presented with full consideration of the anisotropy of the system. Our results show that the system undergoes a transition from Fermi liquid to Mott insulator when the repulsive interaction reaches a critical value. The Kondo effect also can be observed in this system and the pseudogap is suppressed at low temperatures due to the Kondo effect. A feasible experiment protocol to observe these phenomena in an anisotropic triangular optical lattice with cold atoms is proposed, in which the hopping terms are closely related to the lattice confining potential and the atomic interaction can be adjusted via the Feshbach resonance.

关键词： triangular optical lattice cold atoms cluster dynamical approximation

Fabrication and properties of the meander nanowires based on ultra-thin Nb films

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chinese physics B 2014年第8期23卷 521-526页

作者：赵璐金贻荣李洁邓辉郑东宁 Beijing national laboratory for condensed {3. physics Institute of Physics Chinese Academy of Sciences

We report the fabrication and the study of superconducting properties of ultra-thin Nb superconducting meander nanowires, which can be used as superconducting nanowire single-photon detectors （SNSPDs）. The ultra-thin （about 7- nm thick） Nb films are patterned into micro-bridges, and 100-nm wide meander nanowires by using e-beam lithography （EBL）. The average transition temperature （Tc） of the nanowires is about 4.8 K and the critical current density jc is about 2.8 × 10^6 A/cm2. Superconducting characteristics of the specimens at different applied magnetic fields up to 8 T （parallel or perpendicular to the specimen） are systematically investigated. The normalized temperature t （= T/Tc） dependences of the parallel critical field （HcⅡ） for both the micro-bridge and the meander nanowire are almost the same, following the Ginzburg and Landau （GL） formalism for ultra-thin films. However, in perpendicular field and in the vicinity of Tc （〉 0.95Tc）, the critical field Hc⊥ of the nanowire exhibits a down-turn curvature nonlinear temperature dependence while the micro-bridge displays a linear temperature dependence. The nonlinear behavior of Hc⊥ in the nanowire is believed to be due to the fact that in the vicinity of Tc the coherence length becomes larger than the line width. Additionally, the localization of carriers in the nanowire could also contribute to the nonlinear behavior. The resistive transitions could be described by the phase-slip model for quasi-one-dimensional system. Moreover, the hysteresis in I-V curve of the meander nanowires can be illustrated by a simple model of localized normal hotspot maintained by Joule heating.

关键词： Nb meander nanowire critical temperature critical field critical current

Colossal magnetoresistance and spin-glass properties of La(1-x)TexMnO3.x=0.04,0.1)

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chinese Science Bulletin 2003年第13期48卷 1321-1324页

作者： TAN Guotai, DUAN Peng, DAI Shouyu, CHEN Zhenghao, LU Huibin & ZHOU Yueliang laboratory of Optical physics, institute of physics & Center for {3. matter physics, chinese academy of sciences, Beijing 100080, china Correspondence should be addressed to Chen Zhenghao (e-mail: zhchen @***) laboratory of Optical physics Center for Condensed Matter Physics Chinese Academy of Sciences Beijing 100080 China

For the first time, a novel material of La1-x- TexMnO3.(x = 0.04, 0.1), in which the La ions are replaced by the nonmetal element Te in the Chalcogen, has been synthesized. The material has a rhombohedral lattice with the space group of R3., and Te ions have a tetravalence state. The curves of the resistivity vs. temperature indicate that this material has the property of a metal-semiconductor transition and the colossal magnetoresistance (CMR) effect. The maximum magnetoreistance ratio MR=[(0)()]/(0)H? is about 51% at 4 T for x = 0.1. Besides, a spin-glass behavior at low magnetic fields is observed in this compound.

关键词：巨磁电阻 La1-xTexMnO3 镧碲物理性质

High-sensitivity photovoltage based on the interfacial photoelectric effect in the SrTiO_(3.δ)/Si heterojunction

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Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 2080-2083页

作者： WEN Juan 1,GUO HaiZhong 1,XING Jie 2,Lü HuiBin 1,JIN Kui-Juan 1,HE Meng 1 & YANG GuoZhen 1 1 Beijing national laboratory for condensed {3. physics,institute of physics,chinese academy of sciences,Beijing 100190,china 2 School of Materials sciences and Technology,china University of Geosciences,Beijing 100083.china Beijing national laboratory for condensed {3. physics Institute of Physics Chinese Academy of Sciences Beijing China School of Materials sciences and Technology China University of Geosciences Beijing China

A high sensitivity photovoltaic effect has been observed in a heterojunction composed of n-type wide bandgap oxide SrTiO 3.δ and p-type Si fabricated by laser molecular beam *** responsivity of open-circuit photovoltage can reach 10 4 V/W without any amplification under zero bias for the wavelength range from visible to near infrared light in nW-μW *** attribute the high performance of the photovoltage responsivity to the interfacial photoelectric effects in the SrTiO 3.δ /Si *** the experimental results,some ideas can be generalized to improve photovoltaic efficiency and develop high sensitivity photodetectors with wide bandgap oxide materials and Si.

关键词： SrTiO 3.δ/Si heterojunction interfacial photoelectric effect photovoltage