共查询到17条相似文献,搜索用时 93 毫秒
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(8, 0)碳纳米管/碳化硅纳米管异质结输运特性的研究 总被引:1,自引:1,他引:0
A two-probe system of the heterojunction formed by an (8, 0) carbon nanotube (CNT) and an (8, 0) silicon carbide nanotube (SiCNT) was established based on its optimized structure. By using a method combining nonequilibrium Green's function (NEGF) with density functional theory (DFF), the transport properties of the het-erojunction were investigated. Our study reveals that the highest occupied molecular orbital (HOMO) has a higher electron density on the CNT section and the lowest unoccupied molecular orbital (LUMO) mainly concentrates on the interface and the SiCNT section. The positive and negative threshold voltages are +1.8 and -2.2 V, respectively. 相似文献
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Using the method combined non-equilibrium Green’s function with density functional theory, the electronic transport properties of an (8, 0) carbon/boron nitride nanotube heterojunction coupled to Au electrodes were investigated. In the current voltage characteristic of the heterojunction, negative differential resistance was found under positive and negative bias, which is the variation of the localization for corresponding molecular orbital caused by the applied bias voltage. These results are meaningful to modeling and simulating of related electronic devices. 相似文献
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采用基于LMTO-ASA的平均键能计算方法和原子集团展开方法,研究了三组典型的晶格匹配三元合金异质结(GaAs)x(Ge2)1-x/GaAs,(AlAs)x(Ge2)1-x/GaAs和AlxGa1-xAs/GaAs的价带带阶△Ev(x)值。研究表明:AlxGa1-xAs/GaAs异质结的Mv(x)值随合金组分x的变化接近于线性;(GaAs)x(Ge2)1-x/GaAs和(AlAs)x(Ge2)1-x/GaAs的△Ev(x)值随合金组分x的变化是非线性的。△Ev(x)的理论计算值与实验结果相当符合。 相似文献
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对AlxGa1-xAs/GaAs半导体单异质结系统,引入有限高势垒与考虑导带弯曲的真实势,同时计入电子对异质结势垒的隧穿,利用变分法和记忆函数方法讨论在界面光学声子和体纵光学声子的散射下,异质结界面附近电子迁移率随温度的变化关系及其压力效应.结果显示:电子迁移率随温度、压力的增加而减小;且两种声子的散射作用均随压力增强,界面光学声子的变化幅度更大.因此,在讨论压力的情形下,界面光学声子的作用不容忽略. 相似文献
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对AlxGa1-xAs/GaAs半导体单异质结系统,引入有限高势垒与考虑导带弯曲的真实势,同时计入电子对异质结势垒的隧穿,利用变分法和记忆函数方法讨论在界面光学声子和体纵光学声子的散射下,异质结界面附近电子迁移率随温度的变化关系及其压力效应.结果显示:电子迁移率随温度、压力的增加而减小;且两种声子的散射作用均随压力增强,界面光学声子的变化幅度更大.因此,在讨论压力的情形下,界面光学声子的作用不容忽略. 相似文献
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本文对场效应管所用材料的隔离层,δ调制掺杂层,势垒耗尽层等材料结构尺寸,异质结界面的二维电子气浓度,场效应管的夹断电压,沟道电流等以及它们之间的关系进行了计算分析,可作为材料和器件结构设计的依据. 相似文献
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为了研究单壁碳纳米管的电子能带特性及其态密度,本文采用紧束缚法和态密度函数,对无限长碳纳米管进行了理论计算和模拟。结果表明:碳纳米管的电子能带结构与其几何结构密切相关,一般认为扶手型管呈现出金属性;而锯齿管则不同,当n=3k(k为整数)时,其能级存在一个较小的禁带宽度,具有半金属性质;而其它锯齿型管均存在较大的禁带宽度,且禁带宽度随管径的增大而减小,具有半导体性质,这为碳纳米管的电子结构的研究提供了必要且有价值的理论依据。 相似文献
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The electronic structure of the heterojunction is the foundation of the study on its working mechanism. Models of the heterojunctions formed by an (8, 0) boron nitride nanotube and an (8, 0) carbon nanotube with C-B or C-N interface have been established. The structures of the above heterojunctions were optimized with first-principle calculations based on density functional theory. The rearrangements of the heterojunctions concentrate mainly on their interfaces. The highest occupied molecular orbital and the lowest unoccupied molecular orbital of the heterojunctions distribute in the carbon nanotube section. As the band offsets of the above heterojunctions are achieved with the average bond energy method, the band structure is plotted. 相似文献
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Using the method combined non-equilibrium Green’s function with density functional theory,the electronic transport properties of an(8,0) carbon/boron nitride nanotube heterojunction coupled to Au electrodes were investigated.In the current voltage characteristic of the heterojunction,negative differential resistance was found under positive and negative bias,which is the variation of the localization for corresponding molecular orbital caused by the applied bias voltage.These results are meaningful to modeling and simulating on related electronic devices. 相似文献
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A two-probe system of the heterojunction formed by an (8,0) carbon nanotube(CNT) and an (8,0)silicon carbide nanotube (SiCNT) was established based on its optimized structure. By using a method combining nonequilibrium Green's function (NEGF) with density functional theory (DFT), the transport properties of the heterojunction were investigated. Our study reveals that the highest occupied molecular orbital (HOMO) has a higher electron density on the CNT section and the lowest unoccupied molecular orbital (LUMO) mainly concentrates on the interface and the SiCNT section. The positive and negative threshold voltages are1.8 and-2.2 V, respectively. 相似文献
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Catalysts: Stabilization of Single Metal Atoms on Graphitic Carbon Nitride (Adv. Funct. Mater. 8/2017) 下载免费PDF全文
Zupeng Chen Sharon Mitchell Evgeniya Vorobyeva Rowan K. Leary Roland Hauert Tom Furnival Quentin M. Ramasse John M. Thomas Paul A. Midgley Dariya Dontsova Markus Antonietti Sergey Pogodin Núria López Javier Pérez‐Ramírez 《Advanced functional materials》2017,27(8)
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Seiya Suzuki Takuya Iwasaki K. Kanishka H. De Silva Shigeru Suehara Kenji Watanabe Takashi Taniguchi Satoshi Moriyama Masamichi Yoshimura Takashi Aizawa Tomonobu Nakayama 《Advanced functional materials》2021,31(5):2007038
Germanene, a 2D honeycomb germanium crystal, is grown at graphene/Ag(111) and hexagonal boron nitride (h-BN)/Ag(111) interfaces by segregating germanium atoms. A simple annealing process in N2 or H2/Ar at ambient pressure leads to the formation of germanene, indicating that an ultrahigh-vacuum condition is not necessary. The grown germanene is stable in air and uniform over the entire area covered with a van der Waals (vdW) material. As an important finding, it is necessary to use a vdW material as a cap layer for the present germanene growth method since the use of an Al2O3 cap layer results in no germanene formation. The present study also proves that Raman spectroscopy in air is a powerful tool for characterizing germanene at the interfaces, which is concluded by multiple analyses including first-principles density functional theory calculations. The direct growth of h-BN-capped germanene on Ag(111), which is demonstrated in the present study, is considered to be a promising technique for the fabrication of future germanene-based electronic devices. 相似文献
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A detailed density functional study is performed to analyze the TTF/Au (1 1 1) interface, including the effect of the molecular charging energy on the transport gap. Theoretical STM calculations are carried out, and compared with recent STM experimental evidence, for a dilute TTF/Au (1 1 1) structure in order to validate the interface geometry used in our calculations. We show that the alignment between the metal and the organic levels is mainly controlled by the charge transfer between the two materials, as determined by the difference between the molecule Charge Neutrality Level (CNL), and the initial Fermi level. The calculated transport gap is 4.1 eV, and the CNL is found close to the LUMO level, located about 0.7 eV from vacuum. 相似文献