The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Junwei Liu - One of the best experts on this subject based on the ideXlab platform.
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spin filtered edge states with an electrically tunable gap in a two dimensional topological crystalline insulator
Nature Materials, 2014Co-Authors: Junwei Liu, Timothy H Hsieh, Peng Wei, Wenhui Duan, Jagadeesh S MooderaAbstract:Topological crystalline insulators are characterized by metallic states originating from crystal symmetries. A Transistor Device that takes advantage of the quantum properties of the topological crystalline insulating materials SnTe and Pb1−xSnxSe(Te) is now proposed.
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spin filtered edge states with an electrically tunable gap in a two dimensional topological crystalline insulator
arXiv: Mesoscale and Nanoscale Physics, 2013Co-Authors: Junwei Liu, Timothy H Hsieh, Peng Wei, Wenhui Duan, Jagadeesh S MooderaAbstract:Three-dimensional topological crystalline insulators were recently predicted and observed in the SnTe class of IV-VI semiconductors, which host metallic surface states protected by crystal symmetries. In this work, we study thin films of these materials and expose their potential for Device applications. We demonstrate that thin films of SnTe and Pb(1-x)Sn(x)Se(Te) grown along the (001) direction are topologically nontrivial in a wide range of film thickness and carry conducting spin-filtered edge states that are protected by the (001) mirror symmetry via a topological invariant. Application of an electric field perpendicular to the film will break the mirror symmetry and generate a band gap in these edge states. This functionality motivates us to propose a novel topological Transistor Device, in which charge and spin transport are maximally entangled and simultaneously controlled by an electric field. The high on/off operation speed and coupling of spin and charge in such a Device may lead to electronic and spintronic applications for topological crystalline insulators.
Jagadeesh S Moodera - One of the best experts on this subject based on the ideXlab platform.
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spin filtered edge states with an electrically tunable gap in a two dimensional topological crystalline insulator
Nature Materials, 2014Co-Authors: Junwei Liu, Timothy H Hsieh, Peng Wei, Wenhui Duan, Jagadeesh S MooderaAbstract:Topological crystalline insulators are characterized by metallic states originating from crystal symmetries. A Transistor Device that takes advantage of the quantum properties of the topological crystalline insulating materials SnTe and Pb1−xSnxSe(Te) is now proposed.
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spin filtered edge states with an electrically tunable gap in a two dimensional topological crystalline insulator
arXiv: Mesoscale and Nanoscale Physics, 2013Co-Authors: Junwei Liu, Timothy H Hsieh, Peng Wei, Wenhui Duan, Jagadeesh S MooderaAbstract:Three-dimensional topological crystalline insulators were recently predicted and observed in the SnTe class of IV-VI semiconductors, which host metallic surface states protected by crystal symmetries. In this work, we study thin films of these materials and expose their potential for Device applications. We demonstrate that thin films of SnTe and Pb(1-x)Sn(x)Se(Te) grown along the (001) direction are topologically nontrivial in a wide range of film thickness and carry conducting spin-filtered edge states that are protected by the (001) mirror symmetry via a topological invariant. Application of an electric field perpendicular to the film will break the mirror symmetry and generate a band gap in these edge states. This functionality motivates us to propose a novel topological Transistor Device, in which charge and spin transport are maximally entangled and simultaneously controlled by an electric field. The high on/off operation speed and coupling of spin and charge in such a Device may lead to electronic and spintronic applications for topological crystalline insulators.
B T Dai - One of the best experts on this subject based on the ideXlab platform.
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growth of a single wall carbon nanotube film and its patterning as an n type field effect Transistor Device using an integrated circuit compatible process
Nanotechnology, 2008Co-Authors: S H Shiau, C W Liu, Chie Gau, B T DaiAbstract:This study presents the synthesis of a dense single-wall carbon nanotube (SWNT) network on a silicon substrate using alcohol as the source gas. The nanosize catalysts required are made by the reduction of metal compounds in ethanol. The key point in spreading the nanoparticles on the substrate, so that the SWNT network can be grown over the entire wafer, is making the substrate surface hydrophilic. This SWNT network is so dense that it can be treated like a thin film. Methods of patterning this SWNT film with integrated circuit compatible processes are presented and discussed for the first time in the literature. Finally, fabrication and characteristic measurements of a field effect Transistor (FET) using this SWNT film are also demonstrated. This FET is shown to have better electronic properties than any other kind of thin film Transistor. This thin film with good electronic properties can be readily applied in the processing of many other SWNT electronic Devices.
Siegmar Roth - One of the best experts on this subject based on the ideXlab platform.
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reduced contact resistance between an individual single walled carbon nanotube and a metal electrode by a local point annealing
Nanotechnology, 2007Co-Authors: Yunsung Woo, Georg S Duesberg, Siegmar RothAbstract:The achievement of low-resistance contact is a key requirement for carbon-electrode electronics. In this study, we have obtained contacts with very low resistance between an individual single-walled carbon nanotube (SWNT) and palladium (Pd) electrodes using electric-current-induced Joule heating without destroying the field effect Transistor Device that these form. The SWNT is deposited onto Pd electrodes prepatterned on a SiO2/Si substrate, through which an electrical pulse is applied for a microsecond duration. As a result, the source?drain current through the SWNT is greatly increased owing to the elimination of tunnelling barriers between the SWNT and the electrodes. In the case of semiconducting SWNTs, the Schottky barrier is estimated to increase slightly after pulse annealing in some cases, resulting in a relatively high resistance and asymmetrical current?voltage characteristics.
Keunyoung Shin - One of the best experts on this subject based on the ideXlab platform.
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improved electrical performance and transparency of bottom gate bottom contact single walled carbon nanotube Transistors using graphene source drain electrodes
Journal of Industrial and Engineering Chemistry, 2020Co-Authors: Hyeonwoo Shin, Youngjin Kim, Jeong Gon Son, Changhee Lee, Keunyoung ShinAbstract:Abstract A highly transparent and high-performance random-network single-walled carbon nanotubes (r-SWCNTs) Transistor was successfully fabricated by using chemical vapor deposition-grown graphene source/drain (S/D) electrodes. The bottom-gate, bottom-contact geometry was selected for the graphene S/D contact r-SWCNT (Gr-SWCNT) Transistor because of its enhanced gate modulation and good sustainability. A palladium S/D contact r-SWCNT (Pd-SWCNT) Transistor with the same Device geometry was also fabricated for a comparative study. The transmission line method demonstrated that the resistivity of graphene was small enough (∼0.95 Ω μm) to be used as S/D electrodes in a single Transistor Device, and the contact resistance of Gr-SWCNTs was much lower than that of Pd-SWCNTs. Particularly, the correlation between the applied gate voltage and the sheet resistance is strongly dependent on the r-SWCNT film density. The resulting Gr-SWCNT Transistor exhibits high mobility and good on/off current ratio compared to the Pd-SWCNT Transistor. The high charge injection originated from the ohmic contact behavior and dense r-SWCNT channel formation by the enhancement of selective wetting due to the surface energy matching between the r-SWCNT semiconductor and graphene S/D electrodes. Thus, this approach can encourage creating highly transparent and high-performance carbon-based field effect Transistor.