Analysis of hopping conduction in semiconducting and metallic carbon nanotube devices (original) (raw)

Pool-Frenkel emission and hopping conduction in semiconducting carbon nanotube transistor

2009

The effect of using EBL with devices incorporating CNT has also been investigated. The effect on metallic and semiconducting CNT exposure in the channel of the transistor devices was examined and a physical mechanism for the variations discussed. We show that the subsequent generation of trap states along the CNT channel varies the conduction mechanism of the nanotube and has a significant effect on device performance. Metallic and semiconducting CNT react very differently, with an apparent increased localization effect in the metallic tubes responsible for dramatic decreases in conductance.

Effect of Ar+ irradiation on the behaviour of carbon nanotube transistor

Physica Status Solidi B-basic Solid State Physics, 2006

The characteristics of carbon nanotube field effect transistor are investigated after the whole device is irradiated with Ar+ ions. The resistance become much higher due to the electron scattering at vacancies produced by Ar+ irradiation. In addition, the subthreshold slop, S, (dVG/d(log ID)) increases and the Schottky barrier height decreases after the irradiation, which imply the interface states generated within the band gap of the semiconducting single walled carbon nanotube. Therefore, we suggest a way that makes a transparent contact for electron transport by manipulating the vacancy formation at the interface between nanotube and metal leads. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Ion irradiation effects on conduction in single-wall carbon nanotube networks

Applied Physics A-materials Science & Processing, 2008

We have measured how irradiation by Ar+ and N+ ions modifies electronic conduction in single-wall carbon nanotube (SWNT) networks, finding dramatically different effects for different thicknesses. For very thin transparent networks, ion irradiation increases localization of charge carriers and reduces the variable-range hopping conductivity, especially at low temperatures. However, for thick networks (SWNT paper) showing metallic conductivity, we find a relatively sharp peak in conductivity as a function of irradiation dose. Our investigation of this peak reveals the important role of thermal annealing extending beyond the range of the irradiating ions, and shows the dependence on the morphology of the samples. We propose a simple model that accounts for the temperature-dependent conductivity.

Response of carbon nanotube transistors to electron beam exposure

2007

We study the effect of local charge irradiation on carbon nanotube field effect transistors (CNT-FET), in order to determine the nature of the degradation of the electrical characteristics of CNT-FETs exposed to charged beams, as for example it happens during the fabrication of the device.