Field emission properties of CNT-ZnO composite materials

Abstract

CNT-ZnO composite materials were successfully grown by thermal chemical vapor deposition (thermal CVD). First, Multiwalled Carbon nanotubes were synthesized in the temperature range of 500-700 degrees C. After coating Au nanoparticles on such grown CNTs, ZnO nanowires were synthesized via Zn evaporation method at 500 degrees C. SEM images showed that these CNT-ZnO composites were spinous, and XRD analyses showed that the spinal ZnO were crystalline. The turn-on field of CNT-ZnO composite materials with 500 degrees C growth temperature of underlying CNTs was 3.72 V/mu m, which was 5.58 V/mu m for CNTs grown at 500 degrees C. It was also found that the higher temperature (<550 degrees C) the underlying CNTs were grown at, the better field emission properties CNT-ZnO composite materials have. The WIG ratio from Raman spectroscopy of CNTs decreased as the growth temperature of CNTs increased. The graphitization of underlying CNTs played an important role in the Field emission of CNT-ZnO composite materials. (c) 2008 Elsevier B.V. All rights reserved.