Field-emission characteristics of carbon buckypaper

Abstract

Carbon buckypaper was investigated with respect to field-emission properties and long-term stability, especially under well-defined stress conditions. The carbon buckypaper field emitters showed a threshold field strength of about $\text{1\hspace{0.17em}}\mathrm{V}\mathrm{ \mu }{\mathrm{m}}^{\text{−1}}$ for an emission current of 1 nA. Field-emission current densities of more than $\text{10\hspace{0.17em}}\mathrm{mA} {\mathrm{cm}}^{\text{−2}}$ are measured for higher applied field strengths. The main focus of our investigations is the interaction of field emission and vacuum conditions. In this contribution, reproducible stress tests with microdischarges are presented. Higher emission current densities of about $\text{100\hspace{0.17em}}\mathrm{mA} {\mathrm{cm}}^{\text{−2}}$ increased ionization, and luminescence out of the emission zone even appears before the microdischarges start. After arcing with microdischarges, the carbon buckypaper field emission has lower emission current density and lower variation range. However, the contribution demonstrates the advantages of carbon buckypaper as a large-array electron field emitter for cold-cathode applications.