Temperature-dependent electrical and photo-sensing properties of horizontally-oriented carbon nanotube networks synthesized by sandwich-growth microwave plasma chemical vapor deposition

Abstract

The electrical and photo-sensing properties of horizontally-oriented interconnected carbon nanotube networks (CNT-NWs) prepared by means of a microwave plasma chemical vapor deposition sandwich-growth process are investigated. The temperature-dependent dark and illuminated current-voltage and transfer characteristics of CNT-NW-assisted devices are measured. Results show that the current-voltage characteristics of the devices exhibit nonlinear behavior, and the current can be further modulated by a gate voltage, revealing p-type semiconducting behavior with a device mobility of similar to 14.5 cm(2)/V.s and an on-off current ratio of -10(3). Moreover, when the CNT-NW-assisted devices are irradiated with 1.25-25 mu m infrared (IR) from 300 to 11 K, the photo currents increase approximately 1.1- to 2.7-fold compared to the dark currents at +/- 2 V bias voltage. Such results demonstrate that the presented CNT-NWs have high potential for IR photo-sensor applications. (C) 2012 Elsevier B.V. All rights reserved.