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Transistor Channel (transistor + channel)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Insulator Polarization Mechanisms in Polyelectrolyte-Gated Organic Field-Effect Transistors

ADVANCED FUNCTIONAL MATERIALS, Issue 20 2009
Oscar Larsson
Abstract Electrolyte-gated organic field-effect transistors (OFETs) hold promise for robust printed electronics operating at low voltages. The polarization mechanism of thin solid electrolyte films, the gate insulator in such OFETs, is still unclear and appears to limit the transient current characteristics of the transistors. Here, the polarization response of a thin proton membrane, a poly(styrenesulfonic acid) film, is controlled by varying the relative humidity. The formation of the conducting transistor channel follows the polarization of the polyelectrolyte, such that the drain transient current characteristics versus the time are rationalized by three different polarization mechanisms: the dipolar relaxation at high frequencies, the ionic relaxation (migration) at intermediate frequencies, and the electric double-layer formation at the polyelectrolyte interfaces at low frequencies. The electric double layers of polyelectrolyte capacitors are formed in ,1,µs at humid conditions and an effective capacitance per area of 10,µF cm,2 is obtained at 1,MHz, thus suggesting that this class of OFETs might operate at up to 1,MHz at 1,V. [source]

Active Control of Epithelial Cell-Density Gradients Grown Along the Channel of an Organic Electrochemical Transistor

ADVANCED MATERIALS, Issue 43 2009
Maria H. Bolin
Complex patterning of the extracellular matrix, cells, and tissues under in situ electronic control is the aim of the technique presented here. The distribution of epithelial cells along the channel of an organic electrochemical transistor is shown to be actively controlled by the gate and drain voltages, as electrochemical gradients are formed along the transistor channel when the device is biased.. [source]

Experimental and theoretical investigation of terahertz optical-beating detection by plasma waves in high electron mobility transistors

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2008
H. Marinchio
Abstract A photomixed laser beam of two 1.55 mm cw lasers is used to obtain interband photoexcitation at the difference frequency and at room temperature in submicron gate-length InAlAs/InGaAs transistors. Results show the clear excitation of plasma oscillation modes in the transistor channel. Fundamental plasma resonant frequency and its odd harmonics can be tuned with the applied gate voltage. Numerical simulations have also been performed using a hydrodynamic approach coupled to a pseudo-2D Poisson equation. Numerical results are in qualitative agreement with experiments and confirm optical beating detection at terahertz frequencies. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Low power switched-current circuits with low sensitivity to the rise/fall time of the clock

INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 5 2010
Radek Rudnicki
Abstract The switched-current (SI) technique permits realizing analog discrete-time circuits in standard digital CMOS technology. A very important property of the analog part of a system on a chip is the possibility it offers for realizing some functions of a digital circuit, but with reduced power consumption. In this paper, a low power SI integrator is presented. It is shown that an integrator consuming a fraction of a milliwatt can be designed in 0.35µm CMOS technology with the use of narrow transistor channels, and with the channel length as a design parameter. The impact of the rise/fall time of the clock signal on the integrator operation is observed. It is shown that this effect can be reduced when the proper switch dimensions are taken for the integrator. Analysis and measurements of the integrator noise are presented. The integrator was built with equal size transistors, yielding less sensitivity to variations in production parameters. An experimental chip in 0.35µm CMOS technology was fabricated, and measurements are compared with results obtained during analysis and simulations. In order to verify the properties of the designed integrator experimentally, a first-order filter is built with the use of elementary cells on the chip. Copyright © 2008 John Wiley & Sons, Ltd. [source]