Enhanced field emission properties from AlN nanowires synthesized on conductive graphite substrate

Large-scale AlN nanowires have been grown on flexible and conductive graphite substrate through the catalyst-free chemical vapor deposition (CVD). All the as-grown samples are hexagonal wurtzite structure and grow preferentially along the c-axis. The comparative study on the field emission (FE) properties of AlN nanowires grown on graphite sheet and Si substrates indicates that AlN nanowires grown directly on conductive substrates exhibit good FE properties with low turn on field of 4.9 V/mm at a current density of 10 mA/cm(2) and low threshold field of 6.7 V/mm at 1 mA/cm(2). The enhanced FE property is due to the tapered structures of nanowires with sharp tips and high aspect ratio, and the better electrical contact between conductive graphite substrate and field emitters. These results demonstrate the potential applications of the AlN nanowires grown on graphite sheet in optoelectronic and field-emission nanodevices. (C) 2015 Elsevier B.V. All rights reserved.