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Peidong Yang

Bio: Peidong Yang is an academic researcher from University of California, Berkeley. The author has contributed to research in topics: Nanowire & Perovskite (structure). The author has an hindex of 183, co-authored 562 publications receiving 144351 citations. Previous affiliations of Peidong Yang include Max Planck Society & University of California, Santa Barbara.


Papers
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Proceedings ArticleDOI
01 Jan 2004
TL;DR: In this article, the authors proposed two different types of devices to use this unipolar nature of solution, i.e. transistors and batteries, to control ion transport in nanoscale channels.
Abstract: Ion transport in nanoscale channels has recently received increasing attention. Much of that has resulted from experiments that report modulation of ion transport through the protein ion channel, α-hemolysin, due to passage of single biomolecules of DNA or proteins [1]. This has prompted research towards fabricating synthetic nanopores out of inorganic materials and studying biomolecular transport through them [2]. Recently, the synthesis of arrays of silica nanotubes with internal diameters in the range of 5–100 nm and with lengths 1–20 μm was reported [3]. These tubes could potentially allow new ways of detecting and manipulating single biomolecules and new types of devices to control ion transport. Theoretical modeling of ionic distribution and transport in silica nanotubes, 30 nm in diameter and 5 μm long, suggest that when the diameter is smaller than the Debye length, a unipolar solution of counterions is created within the nanotube and the coions are electrostatically repelled [4]. We proposed two different types of devices to use this unipolar nature of solution, i.e. ‘transistor’ and ‘battery’. When the electric potential bias is applied at two ends of a nanotube, ionic current is generated. By locally modifying the surface charge density through a gate electrode, the concentration of counterions can be depleted under the gate and the ionic current can be significantly suppressed. This could form the basis of a unipolar ionic field-effect transistor. By applying the pressure bias instead of electric potential bias, the fluid flow is generated. Because only the counterions are located inside the channel, the streaming current and streaming potential are generated. This could form the basis of an electro-chemo-mechanical battery. In the present study, transport phenomena in nanofluidic channels were investigated and the performance characteristics were evaluated using continuum dynamics.Copyright © 2004 by ASME

1 citations

Journal ArticleDOI
TL;DR: In this paper, the authors focus on one-dimensional (1D) semiconductor subwavelength optical elements and assess their potential use as active and passive components in photonic devices, including spontaneous emission, ultrafast carrier dynamics, cavity resonance feedback (lasing), photodetection, and waveguiding.
Abstract: This article focuses on one-dimensional (1D) semiconductor subwavelength optical elements and assesses their potential use as active and passive components in photonic devices. An updated overview of their optical properties, including spontaneous emission, ultrafast carrier dynamics, cavity resonance feedback (lasing), photodetection, and waveguiding, is provided. The ability to physically manipulate these structures on surfaces to form simple networks and assemblies is the first step toward integrating chemically synthesized nanomaterials into photonic circuitry. These high index semiconductor nanowires are capable of efficiently guiding light through liquid media, suggesting a role for such materials in microfluidics-based biosensing applications.

1 citations

Patent
03 Jan 2007
TL;DR: In this article, a method for the non-catalytic growth of nanowires is provided, which includes a reaction chamber with the chamber having an inlet end, an exit end and capable of being heated to an elevated temperature.
Abstract: A method for the non-catalytic growth of nanowires is provided. The method includes a reaction chamber with the chamber having an inlet end, an exit end and capable of being heated to an elevated temperature. A carrier gas with a flow rate is allowed to enter the reaction chamber through the inlet end and exit the chamber through the exit end. Upon passing through the chamber the carrier gas comes into contact with a precursor which is heated within the reaction chamber. A collection substrate placed downstream from the precursor allows for the formation and growth of nanowires thereon without the use of a catalyst. A second embodiment of the present invention is comprised of a reaction chamber, a carrier gas, a precursor target, a laser beam and a collection substrate. The carrier gas with a flow rate and a gas pressure is allowed to enter the reaction chamber through an inlet end and exit the reaction chamber through the exit end. The laser beam is focused on the precursor target which affords for the evaporation of the precursor material and subsequent formation and growth of nanowires on the collection substrate.

1 citations

Proceedings ArticleDOI
01 Jan 2002
TL;DR: In this article, the size effect on the nanowire thermal conductivity has been investigated and the authors also solved the Boltzmann transport equation (BTE) and showed that the MD results fit reasonably well with the BTE solutions.
Abstract: One-dimensional (1D) materials such as various kinds of nanowires and nanotubes have attracted a lot of attention recently because of their potential applications in nanoelectronic and energy conversion devices [1–3]. As the size of low dimensional materials is confined to be comparable to the phonon mean free path, the thermal conductivity can be reduced due to boundary scattering. A theoretical study [4] further suggests that as the diameter of a Si nanowire becomes smaller than 20 nm, the phonon dispersion relation can be modified due to the boundary confinement and the phonon group velocities will be less than that of the bulk, which will also tend to reduce the thermal conductivity. A molecular dynamics (MD) simulation [5] has shown that for nanowires of cross sections ranging from 2.58 to 28.62 nm2 , the thermal conductivity could be two orders of magnitude smaller than those of bulk Si crystals in a temperature range from 200 K to 500 K. In their paper, the authors also solved the Boltzmann transport equation (BTE) and showed that the MD results fit reasonably well with the BTE solutions. It is very important to experimentally verify the theoretical predictions and provide experimental data for the device design in nanoelectronic and nanoscale energy conversion devices. However, no systematic experimental studies of the size effect on the nanowire thermal conductivity have been published.Copyright © 2002 by ASME

1 citations


Cited by
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01 May 1993
TL;DR: Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems.
Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

29,323 citations

28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: This work reviews the historical development of Transition metal dichalcogenides, methods for preparing atomically thin layers, their electronic and optical properties, and prospects for future advances in electronics and optoelectronics.
Abstract: Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.

13,348 citations

Journal ArticleDOI
TL;DR: The semiconductor ZnO has gained substantial interest in the research community in part because of its large exciton binding energy (60meV) which could lead to lasing action based on exciton recombination even above room temperature.
Abstract: The semiconductor ZnO has gained substantial interest in the research community in part because of its large exciton binding energy (60meV) which could lead to lasing action based on exciton recombination even above room temperature. Even though research focusing on ZnO goes back many decades, the renewed interest is fueled by availability of high-quality substrates and reports of p-type conduction and ferromagnetic behavior when doped with transitions metals, both of which remain controversial. It is this renewed interest in ZnO which forms the basis of this review. As mentioned already, ZnO is not new to the semiconductor field, with studies of its lattice parameter dating back to 1935 by Bunn [Proc. Phys. Soc. London 47, 836 (1935)], studies of its vibrational properties with Raman scattering in 1966 by Damen et al. [Phys. Rev. 142, 570 (1966)], detailed optical studies in 1954 by Mollwo [Z. Angew. Phys. 6, 257 (1954)], and its growth by chemical-vapor transport in 1970 by Galli and Coker [Appl. Phys. ...

10,260 citations