RF-PECVD synthesis of carbon nanowalls and their field emission properties

Carbon nanowalls (CNWs) were successfully fabricated on various substrates by radio frequency plasma-enhanced chemical vapor deposition using gas mixtures of acetylene, argon and hydrogen without aid of any catalyst or substrate pretreatment. The influence of synthesis parameters on the field emission behaviors of CNWs was investigated in depth. The results showed that the morphology and microstructure of CNWs could be adjusted by growth parameters (temperature, pressure and gas flow rate), and CNWs with sharp edges displayed good field emission properties. Especially, the sample prepared under the pressure of 300 Pa and the temperature of 650 °C with H2 flow rate of 120 sccm exhibited the best field emission performance (the turn-on and threshold fields were 4.7 and 6.0 V/μm, respectively). In addition, the field emission characteristics of CNWs after stability test had no obvious deterioration; however, the morphology and microstructure of CNWs changed.