Electron field emission properties of carbon nanotubes during thermal heating and laser irradiation

Abstract

Multiwall carbon nanotubes, CNTs, were grown by microwave heated chemical vapor deposition. In order to investigate the thermal effect on electron field emission properties of the CNTs, the emission currents were measured for different substrate temperatures. Moreover, the pulsed laser-heating effect was also studied. The field emission properties of the CNTs were enhanced by increasing the substrate temperature as well as by irradiating pulsed laser. However, the emission–current behaviors are quite different. After the substrate was heated from 25 °C to 700 °C, the maximum field emission current density of CNTs increased from 29 μA/cm2 to 1500 μA/cm2, and unstable fluctuation of emission current was observed at temperature higher than 500 °C. On the contrary, when laser pulses were applied, the maximum current density increased to 700 μA/cm2, and the measured current is reversible before and after the laser irradiation.