The effect of localized strain on the electrical characteristics of curved carbon nanotubes

Carbon nanotubes (CNTs) are the emerging alternative for silicon for developing miniatured electromechanical devices in the More than Moore's era. But, the inconsistent pitch distances among the aligned CNTs have limited their outstanding performances. Except for the intertube overlapping, the curved morphology is an important but often ignored factor for the attractive CNTs under van der Waals interaction. Here, we have synthesized a clean and curved CNT structure with a definite curvature radius by introducing micro perturbation. Electrical measurement has demonstrated that the curved structure will limit the on/off ratio by orders of magnitude but can maintain a high output delivery in transistors. This is attributed to the resistance induced by the localized strain and the extra current delivery capability of the inner walls, which can be well explained by the energy band diagram model. Among the curved CNTs, incommensurate double walled CNTs of higher diameter difference are the optimal candidates for delivering a high current output by limiting intertube charge transfer. Our demonstrations and analysis have highlighted the importance of controlling both the chiral structures and morphology of CNTs for the applications of high-performance carbon-based electronics.