Field emission from heat-treated cobalt-containing amorphous carbon composite films on glass substrate

Abstract

Cobalt-containing amorphous carbon composite films have been prepared by filtered cathodic vacuum arc technique (FCVA) with a cobalt-containing graphite target on nickel-coated Corning glass at room temperature. After heat treating at 550 °C in a mixture of acetylene and nitrogen gases, field emission properties of the a-C:Co films were significantly improved. Relatively uniform emission sites and a low threshold electric field of 2 V/μm were obtained without conditioning. The relatively low threshold field is probably attributed to both the graphitization of the composite films caused by cobalt catalyst and modified surface conditions by the heat-treatment process. Moreover, the heat-treated samples still remained a smooth surface with a root mean square roughness of about 22 nm, which could be possibly used to prepare gated carbon emitter array for field emission display.