Stability analysis of doped carbon nanotubes (CNTs)

Carbon nanotubes (CNTs) are being explored due to their massive use in the ever-growing transistor market, and energy storage, etc. The stability of CNTs under dopant/impurity is vital for the successful applications of such systems. Bo et al [1] systematically studied the doping of the (3, 0), (3, 3), (5, 0) CNTs. In this study, we investigated the electronic band structure and stability of doped (5, 0), (5, 5), and (7, 0) CNTs. Dynamical stability was studied through phonon dispersion and ab initio molecular dynamics calculations as implemented in the Quantum-espresso suite [2]. Doping of the groups 13, 14, and 15 elements was studied. We also studied the dependence of stability on doping concentrations. Due to the one-dimensional (1D) nature of the systems, while all our proposed pristine CNTs are stable, many of the CNTs with dopants produce unstable structures. We analyzed the bonding and vibration modes around the dopant atoms to elucidate the underlying cause of instability. The electron-phonon interaction and superconducting transition temperature (Tc) were also calculated in [1], however, we would like to point out that it may be impractical to use the McMillan formula to calculate Tc for 1D systems.

References

[1] Tao Bo et al. The Journal of Physical Chemistry Letters 12.28 (2021), pp. 6667–6675.

[2] Paolo Giannozzi et al. Journal of physics: Condensed matter 29.46 (2017), p. 465901.