Nuclear Quantum Effects in Amorphous Carbon 

Amorphous carbon (a-C) films are of interest for a variety of applications, for example as components of thin-film transistors, solar cells, and microelectromechanical devices. All these applications require an understanding of the electronic and transport properties of a-C films, which we address in our work. Previous studies have shown that nuclear quantum effects (NQEs) have a notable impact on the electronic properties of diamond-like films [1]. Here we investigate the influence of NQEs as a function of the a-C film density on both its electronic and transport properties. By coupling stochastic methods implemented in PyEPFD(https://pyepfd.readthedocs.io/) with first principles molecular dynamics implemented in the Qbox(http://qboxcode.org/) code, we show how hopping and band-like contributions to the electronic conductivity vary as a function of density and how these properties are affected by NQEs at room temperature.  

[1] A. Kundu et al, PNAS 2022;  [2] A. Kundu et al, J. Chem. Theory Comput. 2023, J. Phys. Chem. Lett. 2024.