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81.
《Current Applied Physics》2015,15(5):622-631
Lithium (Li) (0–5 wt%) doped V2O5 thin films were spray deposited at 450 °C onto ITO substrates. Structural analysis using X-ray diffraction and Raman spectroscopy revealed orthorhombic phase of the films. In addition to the V2O5 phase, presence of VO2 peaks due to high deposition temperature is also evident from structural and optical characterization. The non-stoichiometric nature of the films due to loss of the terminal O atom was confirmed from Raman spectroscopy. The direct band gap, indirect bandgap, and phonon energies were also calculated from optical studies. Different charge states of vanadium ions present in the film were identified from X-ray photoelectron spectroscopy study. Results from cyclic voltammetry experiments reflected significant differences between the undoped and Li doped V2O5 samples. Transport properties by Hall-effect measured at room temperature indicated significant increase in conductivity, carrier concentration and mobility of V2O5 thin films on doping with Li. A Dye Sensitized Solar Cell (DSSC) was fabricated using mobility enhanced 5 wt% Li doped V2O5 film as photoanode and its efficiency was found to be 2.7%. A simple electrochromic cell is fabricated using undoped V2O5 thin film to demonstrate the colour change. 相似文献
82.
A facile method is proposed to obtain microwave absorbing materials (MAMs), which possess strong microwave absorption properties in low‐frequency range. By simply mechanical mixing, the obtained Fe3O4–poly (3,4‐ethylenedioxythiophene) (PEDOT) hybrids exhibit more excellent microwave absorbing properties than that of Fe3O4 or PEDOT individually. The analysis on the microwave absorbing properties of the Fe3O4–PEDOT hybrids indicates that the excellent microwave absorbing properties are ascribed to several factors, like the dielectric loss, the interface polarization, eddy current effect, natural ferromagnetic resonance, and the impedance as well as the thickness of the coating. The Fe3O4–PEDOT hybrids with appropriate mass ratios of PEDOT to Fe3O4 (represented by (PEDOT)/(Fe3O4)) show superior microwave absorbing property at low frequency. When the thickness is 4 mm, the reflection loss of the sample reached ?15.8 dB at 3.2 GHz with (PEDOT)/(Fe3O4) of 3 and ?31.4 dB at 4.5 GHz with (PEDOT)/(Fe3O4) of 2, respectively. The obtained Fe3O4–PEDOT MAMs will have a promising application in the practical industry and commerce affairs. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
83.
84.
Probing the Zintl–Klemm Concept: A Combined Experimental and Theoretical Charge Density Study of the Zintl Phase CaSi 下载免费PDF全文
M.Sc. Iryna M. Kurylyshyn Prof. Dr. Thomas F. Fässler M.Sc. Andreas Fischer Dipl.‐Phys. Christoph Hauf Dr. Georg Eickerling Dipl.‐Phys. Manuel Presnitz Prof. Dr. Wolfgang Scherer 《Angewandte Chemie (International ed. in English)》2014,53(11):3029-3032
The nature of the chemical bonds in CaSi, a textbook example of a Zintl phase, was investigated for the first time by means of a combined experimental and theoretical charge density analysis to test the validity of the Zintl–Klemm concept. The presence of covalent Si? Si interactions, which were shown by QTAIM analysis, supports this fundamental bonding concept. However, the use of an experimental charge density study and theoretical band structure analyses give clear evidence that the cation–anion interaction cannot be described as purely ionic, but also has partially covalent character. Integrated QTAIM atomic charges of the atoms contradict the original Zintl–Klemm concept and deliver a possible explanation for the unexpected metallic behavior of CaSi. 相似文献
85.
Band‐Gap Manipulations of Monolayer Graphene by Phenyl Radical Adsorptions: A Density Functional Theory Study 下载免费PDF全文
Phenyl radical (Ph.) adsorption on monolayer graphene sheets is used to investigate the band‐gap manipulation of graphene through density functional theory. Adsorption of a single Ph. on graphene breaks the aromatic π‐bond and generates an unpaired electron, which is delocalized to the ortho or para position. Adsorption of a second radical at the ortho or para position saturates the radical by electron pairing and results in semiconducting graphene. Adsorption of a second radical at the ortho position (ortho–ortho pairing) is found to be more favorable than adsorption at the para position (ortho–para pairing), and the ortho–ortho pairing has stronger effects on band‐gap opening compared with ortho–para pairing. Adsorption of even numbers of Ph. on graphene by ortho–ortho and ortho–para pairings, in general, increases the band gap. Our study shows promise of band‐gap manipulation in monolayer graphene by Ph. adsorption, leading to potential wider applications of graphene. 相似文献
86.
Single atom chemically doped graphene has been theoretically studied by density functional theory. The largest band gap, 0.62 eV, appears in arsenic atom doped graphene, then 0.60 eV comes by the tin atom, whose deformations can neither be ignored. It is also found that oxygen and iron single atom embedded graphene can open band gap by 0.52 and 0.54 eV, respectively. Moreover, doping O atom shows little distortion and high stability by charge redistribution. The band gap of Fe doped graphene is opened by orbital hybridization. The other heteroatom doped results are a little inferior to them. 相似文献
87.
Masahiro Terashima Takuya Miyayama Tetsuro Shirao Hin Wai Mo Yasuhiro Hatae Hiroshi Fujimoto Katsumi Watanabe 《Surface and interface analysis : SIA》2020,52(12):948-952
Low-energy inverse photoelectron spectroscopy (LEIPS) and ultraviolet photoelectron spectroscopy (UPS) incorporated into the multitechnique XPS system were used to probe the ionization potential and the electron affinity of organic materials, respectively. By utilizing gas cluster ion beam (GCIB), in situ analyses and depth profiling of LEIPS and UPS were also demonstrated. The band structures of the 10-nm-thick buckminsterfullerene (C60) thin film on Au (100 nm)/indium tin oxide (100 nm)/glass substrate were successfully evaluated in depth direction. 相似文献
88.
研究了加法半群为半格的半环类S+l中的乘法带半环和矩形带半环类BR中的乘法带半环;给出了ID半环中乘法带半环的结构定理,即ID∩.■°D=.■z∨.■z∨D. 相似文献
89.
建立了一种适用于分析冰毒杂质的方法,并分析其形成原因。将冰毒样品溶于1 mL 0.1 mol/L pH7.0的磷酸盐缓冲液(4份缓冲液1份10%Na2CO3),杂质用0.5 mL乙酸乙酯萃取。结果共有8种物质被检出。N-甲酰甲基安非他明、N-乙酰甲基安非他明在样品中出现,说明此批冰毒由苯丙酮(phenyl-2-propanone,P-2-P)经Leuckart法合成。N-乙基甲基安非他明的检出,则说明用于合成此批冰毒的P-2-P由苯甲醛和硝基乙烷合成。从实验结果看,该法可以满足冰毒杂质分析的需要,为分析冰毒杂质成分的成因、判断冰毒样品的合成路径提供重要信息。 相似文献
90.
通过分子动力学模拟,观察到[001]取向的四方氧化锆纳米柱在拉伸载荷下具有两个线弹性变形的应力-应变关系.这一现象是四方结构向单斜结构相变的结果 .为了进一步阐明应力-应变曲线,进行了包括晶体结构分析和原子应变计算在内的详细研究.晶格取向强烈影响塑性变形机制,即[001]和[111]取向的纳米柱在拉伸载荷下经历相变,而沿[110]取向的纳米柱导致脆性断裂.观察到显著的温度效应,随着温度从300K升高到1500K,弹性模量从573.45GPa线性降低到482.65GPa.此外,还用轻推弹性带(NEB)理论估算了相变能垒,观察到相变能垒随温度的升高而降低.这一工作将有助于加深对氧化锆的四方相到单斜相转变和纳米尺度力学行为的理解. 相似文献