| 1. |
- Jing, Yumei, et al.
(författare)
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A Single-Electron Transistor Made of a 3D Topological Insulator Nanoplate
- 2019
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 31:42
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Tidskriftsartikel (refereegranskat)abstract
- Quantum confined devices of 3D topological insulators are proposed to be promising and of great importance for studies of confined topological states and for applications in low-energy-dissipative spintronics and quantum information processing. The absence of energy gap on the topological insulator surface limits the experimental realization of a quantum confined system in 3D topological insulators. Here, the successful realization of single-electron transistor devices in Bi2Te3 nanoplates using state-of-the-art nanofabrication techniques is reported. Each device consists of a confined central island, two narrow constrictions that connect the central island to the source and drain, and surrounding gates. Low-temperature transport measurements demonstrate that the two narrow constrictions function as tunneling junctions and the device shows well-defined Coulomb current oscillations and Coulomb-diamond-shaped charge-stability diagrams. This work provides a controllable and reproducible way to form quantum confined systems in 3D topological insulators, which should greatly stimulate research toward confined topological states, low-energy-dissipative devices, and quantum information processing.
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| 2. |
- Jing, Yumei, et al.
(författare)
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Weak antilocalization and electron-electron interaction in coupled multiple-channel transport in a Bi2Se3 thin film.
- 2016
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 8:4, s. 1879-1885
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Tidskriftsartikel (refereegranskat)abstract
- The electron transport properties of a topological insulator Bi2Se3 thin film are studied in Hall-bar geometry. The film with a thickness of 10 nm is grown by van der Waals epitaxy on fluorophlogopite mica and Hall-bar devices are fabricated from the as-grown film directly on the mica substrate. Weak antilocalization and electron-electron interaction effects are observed and analyzed at low temperatures. The phase-coherence length extracted from the measured weak antilocalization characteristics shows a strong power-law increase with decreasing temperature and the transport in the film is shown to occur via coupled multiple (topological surface and bulk states) channels. The conductivity of the film shows a logarithmical decrease with decreasing temperature and thus the electron-electron interaction plays a dominant role in quantum corrections to the conductivity of the film at low temperatures.
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| 3. |
- Meng, Mengmeng, et al.
(författare)
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Strong spin-orbit interaction and magnetotransport in semiconductor Bi2O2Se nanoplates
- 2018
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 10:6, s. 2704-2710
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Tidskriftsartikel (refereegranskat)abstract
- Semiconductor Bi2O2Se nanolayers of high crystal quality have been realized via epitaxial growth. These two-dimensional (2D) materials possess excellent electron transport properties with potential application in nanoelectronics. It is also strongly expected that the 2D Bi2O2Se nanolayers can be an excellent material platform for developing spintronic and topological quantum devices if the presence of strong spin-orbit interaction in the 2D materials can be experimentally demonstrated. Herein, we report the experimental determination of the strength of spin-orbit interactions in Bi2O2Se nanoplates through magnetotransport measurements. The nanoplates are epitaxially grown by chemical vapor deposition, and the magnetotransport measurements are performed at low temperatures. The measured magnetoconductance exhibits a crossover behavior from weak antilocalization to weak localization at low magnetic fields with increasing temperature or decreasing back gate voltage. We have analyzed this transition behavior of magnetoconductance based on an interference theory, which describes quantum correction to the magnetoconductance of a 2D system in the presence of spin-orbit interaction. Dephasing length and spin relaxation length are extracted from the magnetoconductance measurements. Compared to the case of other semiconductor nanostructures, the extracted relatively short spin relaxation length of ∼150 nm indicates the existence of a strong spin-orbit interaction in Bi2O2Se nanolayers.
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| 4. |
- Zheng, Wenshan, et al.
(författare)
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Patterning two-dimensional chalcogenide crystals of Bi2Se3 and In2Se3 and efficient photodetectors.
- 2015
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Patterning of high-quality two-dimensional chalcogenide crystals with unique planar structures and various fascinating electronic properties offers great potential for batch fabrication and integration of electronic and optoelectronic devices. However, it remains a challenge that requires accurate control of the crystallization, thickness, position, orientation and layout. Here we develop a method that combines microintaglio printing with van der Waals epitaxy to efficiently pattern various single-crystal two-dimensional chalcogenides onto transparent insulating mica substrates. Using this approach, we have patterned large-area arrays of two-dimensional single-crystal Bi2Se3 topological insulator with a record high Hall mobility of ∼1,750 cm(2) V(-1) s(-1) at room temperature. Furthermore, our patterned two-dimensional In2Se3 crystal arrays have been integrated and packaged to flexible photodetectors, yielding an ultrahigh external photoresponsivity of ∼1,650 A W(-1) at 633 nm. The facile patterning, integration and packaging of high-quality two-dimensional chalcogenide crystals hold promise for innovations of next-generation photodetector arrays, wearable electronics and integrated optoelectronic circuits.
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