Light emission and degradation of single-walled carbon nanotube filament

Abstract

Household light bulbs were fabricated using macroscopically long and aligned single-walled carbon nanotube (SWNT) ropes as filaments. It was found that the SWNT filament could emit bright light when an electric current was passed through it. The light spectrum from the SWNT filament showed a nonblackbody characteristic of the thermal emission, and its infrared emission was almost completely suppressed possibly due to the “photonic band-gap” effect that originates in the loose fibrous bundle structure of the SWNT filament. The electrical resistance of the SWNT filament was found to first increase, and then continually decrease during light emission. It was also found that an electric current could cause degradation and burnout of the SWNT filament and result in complete amorphization, and that an interesting mushroomlike carbon structure was formed due to the carbon evaporation of the nanotube filament during light emission.