Chirality transitions and transport properties of individual few-walled carbon nanotubes as revealed by in situ TEM probing

Highlights: • We present an in situ TEM probing method to change the chirality of few-walled carbon nanotubes and correlate such changes with the electronic transport properties. • The chirality of carbon nanotubes was changed by programmed bias pulses. The chirality transitions of each carbon shell were characterized by nanobeam electron diffraction. Supported by molecular dynamics simulations, a preferred transition path through nucleation of Stone–Wales defects and propagation of (0, 1) type dislocations was revealed. • The changes of electronic transport properties were recorded by in situ TEM electrical measurements and metal-to-semiconductor transition was realized. • This method allows establishing the structure-properties relationship during dynamic processes at the atomic and/or molecular level. Physical properties of carbon nanotubes (CNTs) are closely related to the atomic structure, i.e. the chirality. It is highly desirable to develop a technique to modify their chirality and control the resultant transport properties. Herein, we present an in situ transmission electron microscopy (TEM) probing method to monitor the chirality transition and transport properties of individual few-walled CNTs. The changes of tube structure including the chirality are stimulated by programmed bias pulses and associated Joule heating. The chirality change of each shell is analyzed by nanobeam electron diffraction. Supported by molecular dynamics simulations, a preferred chirality transition path is identified, consistent with the Stone–Wales defect formation and dislocation sliding mechanism. The electronic transport properties are measured along with the structural changes, via fabricating transistors using the individual nanotubes as the suspended channels. Metal-to-semiconductor transitions are observed along with the chirality changes as confirmed by both the electron diffraction and electrical measurements. Apart from providing an alternative route to control the chirality of CNTs, the present work demonstrates the rare possibility of obtaining the dynamic structure-properties relationships at the atomic and molecular levels.