Field emission from carbon nanosheets on pyramidal Si(100)

Carbon nanosheets were synthesized on pyramidal Si( 100) substrates without any catalyst in a microwave plasma-enhanced chemical vapour deposition process. The average length and the growth time of carbon nanosheets were measured to be similar to 300 nm and 10 min, equivalent to a growth rate of similar to 30 nm min(-1). By replacing flat Si( 100) with pyramidal Si( 100) as the substrate, the field emission performance of carbon nanosheets was greatly improved. A low turn-on field of 3.2 V mu m(-1) and a high current density of 2.5 mA cm(-2) at 7.0 V mu m(-1), close to those of carbon nanotube emitters, were achieved. The improvement in field emission was attributed primarily to the pyramidal shape.