Kinking effects and transport properties of coaxial BN-C nanotubes as revealed by in situ transmission electron microscopy and theoretical analysis

The insights into transport behavior and the effects of bending on heterostructures constructed from boron nitride (BN) and carbon (C) nanotubes are important for their flexible device applications because the two systems have equally excellent mechanical but completely different electrical properties. In this work, coaxial BN-C nanotubes have been fabricated and their intrinsic transport properties, as well as structural and electrical response to bending deformation, are studied inside a high-resolution transmission electron microscope. Ballistic, diffusive, and hopping transports within different tube length ranges have been observed. When bending deformation was applied to the tubes, although severe kinking becomes apparent, their transport properties are not notably affected. Meanwhile, both theoretical and experimental analyses confirm that the kink positions depend on the ratio of tube diameter to its length. Possible formation of quantum dots, directly within the kink areas, was predicted through calculations of electron density redistribution between nanotube walls at bending.