Oxygen and ozone oxidation-enhanced field emission of carbon nanotubes

Abstract

Vertically aligned carbon nanotube (CNT) arrays were grown on p-type silicon wafer using acetylene and iron phthalocyanine as the sources of hydrocarbons and catalysts, respectively. The CNT arrays were treated by chemical reagents, such as oxygen $({\mathrm{O}}_2\mathrm{),}$ ozone $({\mathrm{O}}_3\mathrm{),}$ bromine, and acids. When treated by ${\mathrm{O}}_2$ and ${\mathrm{O}}_3,$ the emission current of the CNT array was increased ∼800% along with a decrease of the onset field emission voltage from 0.8 to 0.6 V/μm. Other chemical treatments, e.g., bromination and acid oxidation, lead to poorer field emission performance. The effects of these chemical processes on the field emission properties of CNT arrays will be discussed.