Damage of single-wall carbon nanotube network structure under electric current loading

Abstract

Carbon nanotubes (CNTs) are highly resistant to deformation, and their electrical characteristics are also resistant to degradation at ambient conditions. The damage mechanisms of CNT loaded under high current density are considered to be the oxidation by Joule heating and migration of carbon atoms by high-density electron flows. In this study, the damage characteristics of single-wall CNT (SWCNT) network structures were investigated under accelerated condition with high current loading and heating. The semiconducting and metallic SWCNT network structure specimens of straight shape with 10 μm in width, and 50 μm or 100 μm in length were fabricated by means of photolithographic technique. A testing system applying high current density was constructed and accelerated tests of SWCNT specimens were conducted in the system. The changes of potential drop among the specimen under the constant current loading were recorded until damage occurrence in the SWCNT network structure. The damage characteristics of the specimens were discussed from the changes of microscopic structure and electric resistance under the different accelerated conditions. The disconnection of SWCNT structure was occurred at the cathode and center area of the straight shaped specimen and these were observed in three dimensional laser microscope and SEM images after current loading. There were two mechanisms based on oxidation of Joule heating and electromigration occurred in the SWCNT specimens under high density current loading.

Keywords

• carbon nanotube
• current loading
• high current density
• damage
• photolithography