Selective Sorting of Semiconducting C70@Single‐Walled Carbon Nanotube Heterostructures with Narrow Diameter Distribution

AbstractConsistently arranging molecules within single‐walled carbon nanotube (SWCNT) templates shows promise for creating advanced 1D heterostructures, but diameter variations in raw SWCNTs pose a significant challenge. In this work, a precise synthesis of C70 fullerene‐filled SWCNTs (C70@SWCNTs) is achieved through vapor‐phase filling followed by polymer sorting. As the SWCNT diameter increases, C70 molecules first stack in a single chain, then form unusual configurations, including staggered double chains and double helices—configurations not observed in bulk C70 crystals. SWCNT deformation, which is often overlooked in previous theoretical works, is found to significantly alter the C70 stacking configuration. C70‐SWCNT electronic interactions, particularly charge transfer, allow selective extraction of C70@SWCNTs with narrowly distributed diameters and good semiconducting purity. The sorted C70@SWCNTs have diameters of 1.3–1.4 nm, corresponding to C70‐SWCNT distances of ca. 0.34 nm, where the strongest electronic interactions occur. An on/off current ratio of 10⁴ is achieved in their field‐effect transistors. The synthesis and separation strategy sheds light on the preparation and application of 1D heterostructures.