Structural order and charge transfer in highly strained carbon nanobelts

Abstract

We present a computational study of the atomic morphology, structural order, and charge transfer properties of radially π-conjugated, closed-loop, and highly strained chiral carbon nanobelts (CNBs). The synthesis of nanobelts has recently been achieved [G. Povie, Y. Segawa, T. Nishihara, Y. Miyauchi and K. Itami, Science, 2017, 356, 172–175] and they are considered to be precursors for carbon nanotube synthesis, or in some cases are considered to be a field of application by themselves. Tightly packed solid-state arrays of CNBs are nest-like, similar to carbon nanorings. Molecular dynamics simulations reveal that the solid-state order is largely stable. We estimated the charge transport properties with electronic structural methods. DFT-calculated reorganization energy is found to be 201 meV. Due to the radial π-conjugation and weak intermolecular contacts, the charge transfer electronic coupling between molecular pairs in the solid-state was relatively weak and around 10 meV. The charge transport mobility was simulated by the kinetic Monte Carlo methods and the hole mobility was estimated to be 0.4 cm² V⁻¹ s⁻¹ for the disordered CNBs. It was also found that the hole mobility had sizable anisotropy even in the disordered state. Given the exceptional optoelectronic properties of exotic molecules such as C₆₀ and carbon nanotubes, chiral CNBs and their possible derivatives, as the building blocks of these molecules, will revolutionize such applications.