微纳材料设计与制造研究中心

The structural, energetic and electronic properties of carbon nanobuds (CNBs) with the smallest fullerene C20 covalently attached to the sidewall of single-walled carbon nanotubes (SWNTs) are studied by first-principles calculations. Due to the high curvature of C20 and the resulting chemical activity, the binding between C20 and SWNTs is quite strong. Among different CNB configurations, bond cycloaddition is energetically most favorable. The activation barrier for C20–CNB formation is only one-fourth that of C60 and it would maintain good stability once formed. Our results also reveal that C20–CNB stability depends on the chirality of the SWNTs, and they exhibit tunable band gaps that can be modulated by the density of C20 attached to the SWNTs.