The effect of ball-milling on the dispersion of carbon nanotubes: The electrical conductivity of carbon nanotubes-incorporated ZnO

Nowadays a lot of studies were conducted to improve electronic properties of ZnO for transparent conducting oxide materials using single-wall carbon nanotube (SWCNT). In this study, ZnO nanocomposite films containing 0.1 wt% of SWCNTs were synthesized using a solgel method. Variation in ball-milling time of SWCNTs up to 12 h was introduced to induce a difference in the distribution size and length of SWCNTs. The ball-milling effect was analyzed with scanning electron microscopic studies and electrical property measurement of SWCNTs-incorporated ZnO nanocomposite films. Dispersion and shortening of SWCNTs were observed with increasing ball-milling time: dispersion was saturated but shortening was proceeded. 9 h of ball-milling time was found to optimize dispersion and shortening of SWCNTs, confirmed from the electrical property measurement. With optimized ball-milling time of 9 h, a transmittance in the visible light range of SWCNTs-incorporated ZnO film maintained over 87% of transparency. Also the resistivity of this film (0.53ωcm) was less than that (1.48ωcm) of SWCNTs-incorporating ZnO without a ball-milling.