Field effect

About: Field effect is a research topic. Over the lifetime, 4018 publications have been published within this topic receiving 92613 citations.

Electrical transport properties of individual gallium nitride nanowires synthesized by chemical-vapor-deposition

Abstract: We have synthesized high-quality gallium nitride (GaN) nanowires by a chemical-vapor-deposition method and studied the electrical transport properties. The electrical measurements on individual GaN nanowires show a pronounced n-type field effect due to nitrogen vacancies in the whole measured temperature ranges. The n-type gate response and the temperature dependence of the current–voltage characteristics could be understood by the band bending at the interface of the metal electrode and GaN wire. The estimated electron mobility from the gate modulation characteristics is about 2.15 cm2/V s at room temperature, suggesting the diffusive nature of electron transport in the nanowires.

Modulation of the Electrical Properties of VO2 Nanobeams Using an Ionic Liquid as a Gating Medium

Abstract: Vanadium dioxide (VO2) is a strongly correlated transition metal oxide with a dramatic metal–insulator transition at 67 °C. Researchers have long been interested in manipulating this transition via the field effect. Here we report attempts to modulate this transition in single-crystal VO2 nanowires via electrochemical gating using ionic liquids. Stray water contamination in the ionic liquid leads to large, slow, hysteretic conductance responses to changes in the gate potential, allowing tuning of the activation energy of the conductance in the insulating state. We suggest that these changes are the result of electrochemical doping via hydrogen. In the absence of this chemical effect, gate response is minimal, suggesting that significant field-effect modulation of the metal–insulator transition is not possible, at least along the crystallographic directions relevant in these nanowires.

Room temperature pulsed laser deposited indium gallium zinc oxide channel based transparent thin film transistors

Abstract: Indium gallium zinc oxide deposited by pulsed laser deposition at room temperature was used as a channel layer to fabricate transparent thin film transistors with good electrical characteristics: field effect mobility of 11cm2V−1s−1 and subthreshold voltage swing of 0.20V∕decade. By varying the oxygen partial pressure during deposition the conductivity of the channel was controlled to give a low off-current of ∼10pA and a drain current on/off ratio of ∼5×107. Changing the channel layer thickness was a viable way to vary the threshold voltage. The effect of the gate dielectric on the electrical behavior was also explored.

High field-effect mobility zinc oxide thin film transistors produced at room temperature

Abstract: In this paper we present the first results of thin film transistors produced completely at room temperature using ZnO as the active channel and silicon oxynitride as the gate dielectric. The ZnO-based thin film transistors (ZnO-TFT) present an average optical transmission (including the glass substrate) of 84% in the visible part of the spectrum. The ZnO-TFT operates in the enhancement mode with a threshold voltage of 1.8 V. A field effect mobility of 70 cm 2 /V s, a gate voltage swing of 0.68 V/decade and an on-off ratio of 5 × 10 5 were obtained. The combination of transparency, high field-effect mobility and room temperature processing makes the ZnO-TFT very promising for the next generation of invisible and flexible electronics.

Magnetic Field Effects on Copper Electrolysis

Abstract: The effect of a static magnetic field, B, on the electrolysis of copper in aqueous solution is investigated using linear sweep voltammetry, impedance spectroscopy, chronoamperometry, rotating disk voltammetry, and analysis of fractal growth patterns. Data are obtained in fields of up to 6 T. There is a large enhancement of the electrodeposition rate (up to 300%) from concentrated CuSO4 solution (c ∼1 M) when pH ≤ 1. The effect of the magnetic field is equivalent to that achieved by rotating the electrode. From the pH, viscosity, field direction and concentration dependence of the field effect, the influence of field on the complex impedance, and the equivalence of field and electrode rotation, it is established that the magnetic field influences mass transport by forced convection. Convective flow is modified on a microscopic scale in the boundary layer close to the working electrode. There is no influence on the electrode kinetics. Turbulence sets in for our cell geometry when the product of field and cu...