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Full-Text Articles in Nanoscience and Nanotechnology

Simulation Of Phonon-Assisted Band-To Band Tunneling In Carbon Nanotube Field-Effect Transistors, Siyuranga O. Koswatta, Mark S. Lundstrom, M. P. Anantram, Dmitri E. Nikonov Dec 2005

Simulation Of Phonon-Assisted Band-To Band Tunneling In Carbon Nanotube Field-Effect Transistors, Siyuranga O. Koswatta, Mark S. Lundstrom, M. P. Anantram, Dmitri E. Nikonov

Other Nanotechnology Publications

Electronic transport in a carbon nanotube metal-oxide-semiconductor field effect transistor (MOSFET) is simulated using the nonequilibrium Green’s functions method with the account of electron-phonon scattering. For MOSFETs, ambipolar conduction is explained via phonon-assisted band-to-band (Landau–Zener) tunneling. In comparison to the ballistic case, we show that the phonon scattering shifts the onset of ambipolar conduction to more positive gate voltage (thereby increasing the off current). It is found that the subthreshold swing in ambipolar conduction can be made as steep as 40 mV/decade despite the effect of phonon scattering.


In Vitro And In Vivo Two-Photon Luminescence Imaging Of Single Gold Nanorods, Haifeng Weng, Terry B. Huff, Daniel A. Zweifel, Wei He, Philip S. Low, Alexander Wei, Ji-Xin Cheng Nov 2005

In Vitro And In Vivo Two-Photon Luminescence Imaging Of Single Gold Nanorods, Haifeng Weng, Terry B. Huff, Daniel A. Zweifel, Wei He, Philip S. Low, Alexander Wei, Ji-Xin Cheng

Other Nanotechnology Publications

Gold nanorods excited at 830 nm on a far-field laser-scanning microscope produced strong two-photon luminescence (TPL) intensities, with a cos(4) dependence on the incident polarization. The TPL excitation spectrum can be superimposed onto the longitudinal plasmon band, indicating a plasmon-enhanced two-photon absorption cross section. The TPL signal from a single nanorod is 58 times that of the two-photon fluorescence signal from a single rhodamine molecule. The application of gold nanorods as TPL imaging agents is demonstrated by in vivo imaging of single nanorods flowing in mouse ear blood vessels.


Theoretical Investigation Of Surface Roughness Scattering In Silicon Nanowire Transistors, Jing Wang, Eric Polizzi, Avik Ghosh, Supriyo Datta, Mark Lundstrom Jul 2005

Theoretical Investigation Of Surface Roughness Scattering In Silicon Nanowire Transistors, Jing Wang, Eric Polizzi, Avik Ghosh, Supriyo Datta, Mark Lundstrom

Other Nanotechnology Publications

Using a full three-dimensional (3D), quantum transport simulator, we theoretically investigate the effects of surface roughness scattering (SRS) on the device characteristics of Si nanowire transistors (SNWTs). The microscopic structure of the Si/SiO2 interface roughness is directly treated by using a 3D finite element technique. The results show that (1) SRS reduces the electron density of states in the channel, which increases the SNWT threshold voltage, and (2) the SRS in SNWTs becomes less effective when fewer propagating modes are occupied, which implies that SRS is less important in small-diameter SNWTs with few modes conducting than in planar metal-oxide-semiconductor field-effect-transistors …


Role Of Phonon Scattering In Carbon Nanotube Field-Effect Transistors, Jing Guo, Mark Lundstrom May 2005

Role Of Phonon Scattering In Carbon Nanotube Field-Effect Transistors, Jing Guo, Mark Lundstrom

Other Nanotechnology Publications

The role of phonon scattering in carbon nanotube field-effect transistors 􏰏CNTFETs􏰀 is explored by solving the Boltzmann transport equation using the Monte Carlo method. The results show that elastic scattering in a short-channel CNTFET has a small effect on the source-drain current due to the long elastic mean-free path (mfp)(~ 1µm). If elastic scattering with a short mfp were to exist in a CNTFET, the on current would be severely degraded due to the one-dimensional channel geometry. At high drain bias, optical phonon scattering, which has a much shorter mfp (-10 nm), is expected to dominate, even in a short-channel …