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Enhanced Power Conversion Efficiency in Bulk Heterojunction Polymer Solar Cells Through Dual-interface morphology Modification

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Wuhan University Journal of Natural Sciences 2013年第3期18卷 195-200页

作者： FAN Xi FANG Guojia School of Physics and Technology/Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education Wuhan University

Efficient bulk heterojunction（BHJ） polymer solar cells with a poly（3,4-ethylenedioxythiophene）：poly（styrenesulfonate） hole transfer layer（HTL） were fabricated via controlling the spin coating speed of the HTL solution on a particular fluorinated tin oxide substrates of a high *** shows that the functions of the photovoltaic devices increase with the increase of the HTL surface ***,an imprinting technique was employed to transfer a suitable pattern of nanostructure arrays to the surface of active *** the optimized spin coating speed,the photovoltaic devices exhibited a 28.4% increase in efficiency after this imprinting treatment compared with that of nonimprinted photovoltaic *** is mainly attributed to the achievement of high interface areas between active layers and electrodes,which not only increases optical absorption by scattering but also facilitates charge carrier collection.

关键词： interface morphology imprinting bulk heterojunction polymer solar cell

Effect of travelling magnetic field on interface morphology in directionally solidified Sn-Cd alloy

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Transactions of Nonferrous Metals Society of China 2013年第8期23卷 2454-2459页

作者：王雷沈军王灵水冯周荣傅恒志西北工业大学凝固技术国家重点实验室西安710072

The diversity of interface morphologies is observed for directionally solidified Sn-0.65%Cd alloy under a travelling magnetic field （TMF） in the 4 mm-diameter sample. Under an upward TMF, planar and cellular interface morphologies transform alternately with increasing magnetic flux density （B≤10.3 mT）. The interface morphology transforms from shallow cellular to deep cellular morphology under a weak downward TMF （B=3.2 mT）. When the magnetic flux density increases further, both sides of the interface morphology appear to be slightly inconsistent, but they roughly tend to be planar under a strong downward TMF （BS10.3 mT）. The interface instability may be attributed to the flow driven by the TMF. Moreover, the shape of interface appears to be almost flat under an upward TMF, but deflective under a downward TMF.

关键词： directional solidification travelling magnetic field interface morphology Sn-Cd alloy

Effect of far-field flow on a columnar crystal in the convective undercooled melt

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Chinese Physics B 2015年第1期24卷 423-428页

作者：姬小建陈明文徐小花王自东 School of Mathematics and Physics University of Science and Technology Beijing School of Materials Science and Engineering University of Science and Technology Beijing

The growth behavior of a columnar crystal in the convective undercooled melt affected by the far-field uniform flow is studied and the asymptotic solution for the interface evolution of the columnar crystal is derived by means of the asymptotic expansion method. The results obtained reveal that the far-field flow induces a significant change of the temperature around the columnar crystal and the convective flow caused by the far-field flow accelerates the growth velocity of the interface of the growing columnar crystal in the upstream direction and inhibits its growth velocity in the downstream direction. Our results are similar to the experimental data and numerical simulations.

关键词： columnar crystal far-field uniform flow interface morphology crystal growth

The role of physical properties in explosive welding of copper to stainless steel

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Defence Technology（防务技术） 2023年第4期22卷 88-98页

作者： G.H.S.F.L.Carvalho I.Galvao R.Mendes R.M.Leal A.B.Moreira A.Loureiro Univ Coimbra CEMMPREDepartamento de Engenharia Mec^anicaRua Luís Reis Santos3030-788CoimbraPortugal Department of Industrial Engineering University of FirenzeVia di Santa Marta 350139FirenzeItaly ISEL Departamento de Engenharia Mec^anicaInstituto Politecnico de LisboaRua Conselheiro Emídio Navarro 11959-007LisboaPortugal Univ Coimbra ADAILEDAPDepartamento de Engenharia Mec^anicaRua Luís Reis Santos3030-788CoimbraPortugal LIDA-ESAD.CR Instituto Politecnico de LeiriaRua Isidoro Inacio Alves de Carvalho2500-321Caldas da RainhaPortugal Univ.Porto LAETA/INEGIDept.Eng.Metalúrgica e de MateriaisR.Dr.Roberto Frias4200-465PortoPortugal

This paper investigates the effects of the physical properties on the microstructure and weldability of explosive welding by joining two metals with a significant contrast in thermophysical properties:stainless steel and *** welds between stainless steel and copper were obtained,and the interfacial morphology was wavy,regardless of the position of the *** weldability of dissimilar pairs was found to be more dependent on the relationship between the physical properties of the base materials than on the absolute value of the material *** there is a significant difference in thermal conductivity between the flyer and the base plate,together with a material with a low melting temperature,the weldability of the pair is often *** relative position of the plates affects the interfacial microstructure even when similar morphologies are *** the metallic pairs studied,the wave size was bigger for the configuration in which the ratio between the density of the flyer and the density of the base plate is *** same phenomenon was observed for the impedance:bigger waves were found for a smaller ratio between the impedance of the flyer and the impedance of the base plate.

关键词： Explosive welding Solid-state Copper-stainless steel Dissimilar interface morphology Weldability

Effect of the annealing temperature on the long-term thermal stability of Pt/Si/Ta/Ti/4H–SiC contacts

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Chinese Physics B 2015年第10期24卷 426-431页

作者：程越赵高杰刘益宏孙玉俊王涛陈之战 Department of Physics Shanghai Normal University

The Pt/Si/Ta/Ti multilayer metal contacts on 4H-Si C are annealed in Ar atmosphere at 600°C-1100°C by a rapid thermal processor（RTP）. The long-term thermal stability is evaluated by aging the annealed contact at 600°C in air. The contact＇s properties are determined by current-voltage measurement, and the specific contact resistance is calculated based on the transmission line model（TLM）. Transmission electron microscope（TEM） and energy-dispersive x-ray spectrometry（EDX） are used to characterize the interface morphology, thickness, and composition. The results reveal that a higher annealing temperature is favorable for the formation of an Ohmic contact with a lower specific contact resistance, and causes the rapid degradation of the Ohmic contact in the aging process.

关键词： Ohmic contact annealing temperature thermal stability interface morphology

Effect of buoyancy-driven convection on steady state dendritic growth in a binary alloy

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Chinese Physics B 2013年第11期22卷 467-476页

作者：陈明文王宝王自东 School of Mathematics and Physics University of Science and Technology Beijing School of Materials Science and Engineering University of Science and Technology Beijing

The effect of buoyancy-driven convection on the steady state dendritic growth in an undercooled binary alloy is studied. For the case of the moderate modified Grashof number, the uniformly valid asymptotic solution in the entire region of space is obtained by means of the matched asymptotic expansion method. The analytical results show that the buoyancy- driven convection has a significant effect on the needle-like interface of dendritic growth. Due to the buoyancy-driven convection, the needle-like interface shape of the crystal is changed. When the Peclet number that is not affected by the buoyant flow is less than a certain critical value, the interface shape of the dendrite becomes thinner as the Grashof number increases; when it is larger than the critical value, the interface shape becomes fatter as the Grashof number increases. In the undercooled binary alloy the morphology number plays an active role in the interface shape and leads to the buoyancy effect that is different from the situation for the pure melt. The smaller the morphology number is, the more significant change the interface shape has. As the Peclet number further increases, the effect of buoyancy on the interface diminishes eventually.

关键词： dendrite growth convection interface morphology microgravity conditions

interface MORPHOLOGIES AND MICROSTRUCTURES DURING DENDRITE-TO-CELL TRANSITION AT HIGH GROWTH RATE

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Acta Metallurgica Sinica(English Letters) 1991年第1期4卷 71-74页

作者： LI Jianguo MAO Xiemin FU Hengzhi National Laboratory of solidification Technology,Northwestern Polytechnical University,Xi’an,China Lecturer.Faculty No.403,Northwestern Polytechnical University,Xi’an 710072,China

The interface morphologies and microstruetures of the directionally solidified Ni-5wt-% Cu alloy during dendrite-to-cell transition at high growth rates have been investigated with a newly developed apparatus for unidirectional solidification with the temperature gradient at the solid/liquid interface higher than 1000 K/*** results show that in the vicinity of dendrite-to-cell transition point,the well developed sidebranches become shrivelled with the increase of growth rate and disappear at the dendrite-to-cell transition,and the primary spacing decreases ***,the length of mushy zone decreases greatly dur- ing the dendrite-to-cell *** obtained at high growth rates have very similar morphologies to those at low growth rates,but with much smaller cell spacings and unsmoothed cell walls which may be attributed to the different stability conditions of the cell walls at low and high growth rates respectively.

关键词： cellular growth interface morphology primary spacing rapid solidification dendrite-to-cell transition

interface MORPHOLOGIES AND SOLUTE SEGREGATION OF Al-Li ALLOY 8090 DURING UNIDIRECTIONAL SOLIDIFICATION

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Acta Metallurgica Sinica(English Letters) 1993年第2期6卷 73-77页

作者： LIU Yulin ZHANG Yun ZHAO Hong’en HU Zhuangqi SHI Changxu Institute of Metal Research,Academia Sinica,Shenyang,China Associate Professor,Institute of Metal Research,Academia Sinica,Shenyang 110015,China

The solid-liquid interface morphology and solute segregation behaviour of AI-Li alloy 8090 during unidirectional solidification were studied by the liquid metal quenehing method under varied processing *** solidification rate,RO.75 mm/min (temper- ature gradient,G_L=130℃/cm),the structure revealed of planar or dendritic interface *** the increase of R,the interface morphology becomes cellular from planar gradually,within a narrow *** the greater the R,the,finer the *** of element Cu and impurity elements Fe and Si are quite severe,the interface morphology markedly influences on solute *** solidification at coarse dendrite interface, their segregation ratios are rather great and solidified structure is coarse.

关键词： Al-Li alloy unidirectional solidification interface morphology solute segregation alloy 8090

Interfacial morphology evolution in directionally solidified Al-1.5%Cu alloy

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Transactions of Nonferrous Metals Society of China 2015年第2期25卷 405-411页

作者：屈敏刘林崔岩刘峰斌北方工业大学机械与材料工程学院北京100144 西北工业大学凝固技术国家重点实验室西安710072

The solid-liquid interracial morphology evolution was investigated in directional solidification （DS） of Al-1.5%Cu alloy （mass fraction）. The results show that the solidified microstructural evolution is gradual other than sharp, and the microstructure patterns are interesting and diversiform at the pulling rate ranging from 30 μm/s to 1500 μm/s. Indeed, dendrite to cell transition follows this sequence： dendrites→→banded cellular dendrites→elongated cells and part of dendrites→main elongated cells and little dendrites. Moreover, the present microstructure is not normal microstructure as we saw before. Further, according to the experimental phenomenon, the dendrite to cell transition was studied theoretically. Dendrite tip shape is an important parameter to characterize the dendrite to cell transition. As the dendrite to cell transition is far from equilibrium solidification, non-equilibrium solidification is taken into consideration in calculation. Finally, it is speculated that the dendrite to cell transition would occur at the minimum tip radius.

关键词： Al-Cu alloy dendrite to cell transition directional solidification pulling rate interface morphology