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Gap States of ZnO Thin Films by New Methods:Optical Spectroscopy,Optical Conductivity and Optical Dispersion Energy
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作者 Vali Dalouji Shahram Solaymani +3 位作者 Laya Dejam Seyed Mohammad Elahi TSahar Rezaee Dariush Mehrparvar 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第2期107-110,共4页
The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 an... The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 and 600°C.The values of the cross point between the curves of the real and imaginary parts of the optical conductivity ɑ_1 and ɑ_1 with energy axis of films exhibit values that correspond to optical gaps and are about 3.25-3.3 eV. The maxima of peaks in plots dR/dλ and dT/dλ versus wavelength of films exhibit optical gaps at about 3.12-3.25 eV.The values of the fundamental indirect band gap obtained from the Tauc model are at about 3.14-3.2 eV. It can be seen that films annealed at 600°C have the minimum indirect optical band gap at about 3.15 eV. The films annealed at 600°C have Urbach's energy minimum of 1.38 eV and hence have minimum disorder. The dispersion energy d of films annealed at 500°C has the minimum value of 43 eV. 展开更多
关键词 ZN Gap States of ZnO Thin Films by New Methods:Optical Spectroscopy Optical Conductivity and Optical Dispersion energy OC
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Uncover the Aesthetic Simplicity Associated with Mass Transfer in Energy Materials
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作者 Jiang-Wei Li Jia Li Ke-Chun Wen 《Journal of Electronic Science and Technology》 CAS CSCD 2016年第1期21-24,共4页
Aesthetics,referred frequently to as a philosophical term,has played a starring role in forming and evolving a number of aspects of human society,including arts,politics,economics,ethics,etc.Indeed,exploring and inves... Aesthetics,referred frequently to as a philosophical term,has played a starring role in forming and evolving a number of aspects of human society,including arts,politics,economics,ethics,etc.Indeed,exploring and investigating the aesthetic phenomena in the scientific field have aroused insightful research findings,which in turn has stimulated research interests in such a science-aesthetics field.In particular,better-evaluated aesthetic aspects of the materials field are expected to be uncovered upon the exceedingly-exposed fundamental breakthroughs in researching the basic structure and functionality of materials.In this report,we glimpse into the aesthetic simplicity of energy materials and comprehend specifically the mass transfer functionalities of key categories of energy materials through an intuitive and bottom-up approach.Our effort aspires to shed new lights on the functionality understanding and manipulation of functional materials in general. 展开更多
关键词 Aesthetics applicability electrical conduction energy materials gas diffusion simplicity
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New Activated Carbon with High Thermal Conductivity and Its Microwave Regeneration Performance 被引量:4
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作者 谷雪贤 SU Zhanjun 奚红霞 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2016年第2期328-333,共6页
Using a walnut shellas a carbon source and ZnCl_2 as an activating agent,we resolved the temperature gradient problems of activated carbon in the microwave desorption process.An appropriate amount of silicon carbide w... Using a walnut shellas a carbon source and ZnCl_2 as an activating agent,we resolved the temperature gradient problems of activated carbon in the microwave desorption process.An appropriate amount of silicon carbide was added to prepare the composite activated carbon with high thermalconductivity while developing VOC adsorption-microwave regeneration technology.The experimentalresults show that the coefficient of thermalconductivity of SiC-AC is three times as much as those of AC and SY-6.When microwave power was 480 W in its microwave desorption,the temperature of the bed thermaldesorption was 10 ℃ to 30 ℃ below that of normalactivated carbon prepared in our laboratory.The toluene desorption activation energy was 16.05 k J·mol^(-1),which was 15% less than the desorption activation energy of commercialactivated carbon.This study testified that the process could maintain its high adsorption and regeneration desorption performances. 展开更多
关键词 activated carbon with high thermal conductivity activation energy for desorption VOCs microwave radiation
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Effect of Chemical Doping and Ion Implantation on Cond uctivity of Poly(p-phenylene vinylene) Derivatives 被引量:1
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作者 LI Bao-ming WU Hong-cai LIU Xiao-zeng LI Xiao-qi GAO Chao 《Semiconductor Photonics and Technology》 CAS 2005年第3期188-191,共4页
The surface conductivity of poly [ 2-methoxy-5-(3'-methyl) butoxy]-p-phenylene vinylene (PMOMBOPV) films doped with FeCl3 and H2SO4 by chemical method and implanted by N^+ ions was studied and the comparison of ... The surface conductivity of poly [ 2-methoxy-5-(3'-methyl) butoxy]-p-phenylene vinylene (PMOMBOPV) films doped with FeCl3 and H2SO4 by chemical method and implanted by N^+ ions was studied and the comparison of environmental stability of conductive behavior was also investigated. The energy and dose of N^+ ions were in the rang 15~35 keV and 3. 8×10^15~9. 6×10^16 ions/cm^2, respectively. The conductivity of PMOMBOPV film was enhanced remarkably with the increases of the energy and dose of N^+ ions. For example, the conductivity of PMOMBOPV film was 3. 2×10^-2S/cm when ion implantation was performed with an energy of 35 keV at a dose of 9. 6 × 10^14 ions/cm^2 , which was almost seven orders of magnitude higher than that of film unimplanted. The environmental stability of conductive behavior for ionimplanted film was much better than that of chemical doped films. Moreover, the conductive activation energy of ion-implanted films was measured to be about 0.17 eV. 展开更多
关键词 Ion implantation Chemical doping Poly[2-methoxy-5-(3'-methyl)butoxy]-p-phenylene vinylene Surface conductivity Conductive activation energy
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Impedance Characteristics of MgO-ZrO_2 Ceramics Doped with CeO_2
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作者 Zhao Wenguang An Shengli Song Xiwen 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第2期201-201,共1页
The ultrafine CexMg0.06Zr1-xO1.94 ( x = 0 16% ) powders were synthesized by a chemical co-precipitated method. The pressed compacts were sintered in air at 1300, 1400, 1500, 1600℃ for 3 h, respectively. The phase o... The ultrafine CexMg0.06Zr1-xO1.94 ( x = 0 16% ) powders were synthesized by a chemical co-precipitated method. The pressed compacts were sintered in air at 1300, 1400, 1500, 1600℃ for 3 h, respectively. The phase of the ceramics was characterized by the X-ray diffraction (XRD) method. The conductivity of the ceramics was measured by the AC complex impedance technique at 700- 1200 ℃. The ratio of the cubic phase in the ceramics improves with increasing CeO2 content, leading to a enlargement of the oxygen ionic migration channel. The contact resistance between conductive phase particles decreases with increasing CeO2 content, leading to a lower migration hindrance of the oxygen ionic. Consequently, the ionic conductivity of the ceramics improves with increas- ing CeO2 content. Additionally, an analysis for this phenomenon was also presented. 展开更多
关键词 inorganic nonmetallic materials CexMg0.06Zr1-xO1.94 ceramics AC complex impedance ionic conductivity activation energy for conduction rare earths
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Investigation of electrophysical, photo- and gas-sensitive properties of ZnO–SnO_(2) sol–gel fflms 被引量:1
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作者 Irina A.Gulyaeva Alexandra P.Ivanisheva +4 位作者 Maria G.Volkova Victoria Yu.Storozhenko Soslan A.Khubezhov Ekaterina M.Bayan Victor V.Petrov 《Journal of Advanced Dielectrics》 2024年第1期42-50,共9页
Thin nanocomposite fflms based on tin dioxide with a low content of zinc oxide(0.5–5 mol.%)were obtained by the sol–gel method.The synthesized fflms are 300–600 nm thick and contains pore sizes of 19–29 nm.The res... Thin nanocomposite fflms based on tin dioxide with a low content of zinc oxide(0.5–5 mol.%)were obtained by the sol–gel method.The synthesized fflms are 300–600 nm thick and contains pore sizes of 19–29 nm.The resulting ZnO–SnO_(2) fflms were comprehensively studied by atomic force and Kelvin probe force microscopy,X-ray diffraction,scanning electron microscopy,and high-resolution X-ray photoelectron spectroscopy spectra.The photoconductivity parameters on exposure to light with a wavelength of 470 nm were also studied.The study of the photosensitivity kinetics of ZnO–SnO_(2) fflms showed that the fflm with the Zn:Sn ratio equal to 0.5:99.5 has the minimum value of the charge carrier generation time constant.Measurements of the activation energy of the conductivity,potential barrier,and surface potential of ZnO–SnO_(2) fflms showed that these parameters have maxima at ZnO concentrations of 0.5 mol.%and 1 mol.%.Films with 1 mol.%ZnO exhibit high response values when exposed to 5–50 ppm of nitrogen dioxide at operating temperatures of 200℃ and 250℃. 展开更多
关键词 Sol–gel method ZnO–SnO_(2) films gas-sensitive properties surface potential potential barrier conduction activation energy
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Carbonate-salt-based composite materials for medium- and high-temperature thermal energy storage 被引量:20
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作者 Zhiwei Ge Feng Ye +3 位作者 Hui Cao Guanghui Leng Yue Qin Yulong Ding 《Particuology》 SCIE EI CAS CSCD 2014年第4期77-81,共5页
This paper discusses composite materials based on inorganic salts for medium- and high-temperature thermal energy storage application. The composites consist of a phase change material (PCM), a ceramic material, and... This paper discusses composite materials based on inorganic salts for medium- and high-temperature thermal energy storage application. The composites consist of a phase change material (PCM), a ceramic material, and a high thermal conductivity material. The ceramic material forms a microstructural skeleton for encapsulation of the PCM and structural stability of the composites; the high thermal conductivity material enhances the overall thermal conductivity of the composites. Using a eutectic salt of lithium and sodium carbonates as the PCM, magnesium oxide as the ceramic skeleton, and either graphite flakes or carbon nanotubes as the thermal conductivity enhancer, we produced composites with good physical and chemical stability and high thermal conductivity. We found that the wettability of the molten salt on the ceramic and carbon materials significantly affects the microstructure of the composites. 展开更多
关键词 Thermal energy storage Composite materials Microstructure Thermal conductivity Phase change material
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ELECTRONIC ENERGY BAND STRUCTURE OF MOLECULAR CRYSTALS MCI·(TCNQ)_2 AND ITS RELATIONSHIP WITH THE ELECTRICAL CONDUCTION
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作者 张启元 严继民 《Science China Chemistry》 SCIE EI CAS 1990年第10期1163-1171,共9页
The structure of electronic energy bands, electric charge distribution and the amount of charge transfer of molecular crystals 1-MCI·(TCNQ)_2 (Ⅰ) and 2-MCI· (TCNQ)_2 (Ⅱ) have been studied. The results are... The structure of electronic energy bands, electric charge distribution and the amount of charge transfer of molecular crystals 1-MCI·(TCNQ)_2 (Ⅰ) and 2-MCI· (TCNQ)_2 (Ⅱ) have been studied. The results are: (ⅰ) The dominant contributions to the electrical conductivities for crystals Ⅰ and Ⅱ are from TCNQ molecular columns, and the charge carriers are electrons. (ⅱ) The electrical conduction is mainly due to the hopping of charge carriers between the seats of lattice. (ⅲ) The considerable difference of the electrical conductivities between crystals Ⅰ and Ⅱ is due to the differences between (a) the concentrations of charge carriers n_(AⅠ)~C= 0.9988-|e|/cell and n_(AⅡ)~C=0.0340-|e|/cell; (b) the widths of the energy bands △E_(AⅠ)^(LU)=0.88 eV and △E_(AⅡ)~LU=0.040 eV; (c) the first derivative of E with respect to k, (dE/dk)_(K_FAⅠ)^(LU)=0.27 eV· and (dE/dk)_(K_FAⅡ)~LU=0.0048 eV·; and (d) the difference of energy barriers for the hopping of charge carriers ∈_Ⅱ-∈Ⅰ=2.5-8.8 kJ/mol. 展开更多
关键词 structure of electronic energy bands energy bands and the electrical conductivities molecular crystal MIC·(TCNQ)_2
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Fracture of the humerus caused by a slingshot projectile
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作者 Tahir Ahmed Dar Riyaz Ahmed Dar +1 位作者 Mubashir Rashid Shabir Ahmed Dhar 《Chinese Journal of Traumatology》 CAS 2011年第5期319-320,共2页
Unconventional and 'non-lethal' weapons are being used in crowd control regularly nowadays. The use of these arms is not risk-free. The paramilitary forces in 2010 used the old fashioned slingshots for crowd control... Unconventional and 'non-lethal' weapons are being used in crowd control regularly nowadays. The use of these arms is not risk-free. The paramilitary forces in 2010 used the old fashioned slingshots for crowd control in Kashmir. A young male suffered from a fracture of the distal humerus due to a marble from a slingshot. He was managed by debridement and plaster splintage. Use of apparently innocuous weapons for crowd control is not without risk, as the projectiles fired from them can achieve high velocities and cause significant damage. 展开更多
关键词 Humeral fractures conducted energy weapon injuries FIREARMS
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Dynamics of rotator chain with dissipative boundary 被引量:2
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作者 Pu Ke Zhi-Gang Zheng 《Frontiers of physics》 SCIE CSCD 2014年第4期511-518,共8页
We study the deternfinistic dynanfics of rotator chain with purely mechanical driving on the boundary by stability analysis and numerical sinmlation. Globally synchronous rotation, clustered synchronous rotation, and ... We study the deternfinistic dynanfics of rotator chain with purely mechanical driving on the boundary by stability analysis and numerical sinmlation. Globally synchronous rotation, clustered synchronous rotation, and split synchronous rotation states are identified. In particular, we find that the single-peaked wariance distribution of angular momenta is the consequence of the deterministic dynamics. As a result, the operational definition of temperature used in the previous studies on rotator chain should be revisited. 展开更多
关键词 rotator chain energy conduction
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Cu doped AlSb polycrystalline thin films
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作者 武莉莉 金硕 +5 位作者 曾广根 张静全 李卫 冯良桓 黎兵 王文武 《Journal of Semiconductors》 EI CAS CSCD 2013年第1期20-22,共3页
Cu-doped AlSb polycrystalline films were grown on quartz glass by magnetron co-sputtering.The structural,morphological and electrical properties of the films were studied.The incorporation of copper atoms can result i... Cu-doped AlSb polycrystalline films were grown on quartz glass by magnetron co-sputtering.The structural,morphological and electrical properties of the films were studied.The incorporation of copper atoms can result in the increase of lattice constants,and annealing is helpful to eliminate this deformation.Cu-doped AlSb films exhibit weak n-type conductivity.The results show that the doping effect has a close relationship with the annealing process,meaning that the position of Cu atom in AlSb polycrystalline films might influence the doping effect. 展开更多
关键词 DOPE AlSb film conductivity activation energy
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