Fast and Efficient Purification for Highly Conductive Transparent Carbon Nanotube Films

A combination of thermal oxidation and thermal recovery was used to obtain transparent single-walled carbon nanotube (SWCNT) films with low sheet resistance. The process resulted in the effective removal of impurities and healing of defects in the SWCNTs, thus markedly increasing their conductivity. SWCNT samples before and after the process were analyzed by Raman spectroscopy, scanning and transmission electron microscopy, thermogravimetric analysis, contact angle measurement, and transparent conductive film fabrication. Following purification, the sheet resistance decreased from 5380 to 187 Omega/sq at 80% optical transmittance and at a wavelength of 550 nm. The process requires a short time of about 3 h and produces 30% yield of the as-produced sample.