J. Phys. Chem. C, 124, 8225-8235 (2020) [pdf]

First-Principles Study of Fluorinated Tetrahexcarbon: Stable Configurations, Thermal, Mechanical and Electronic Properties

Mehmet Emin Kilic, Kwang-Ryeol Lee
 

Tetrahexcarbon (TH-carbon) was recently predicted to be a stable two-dimensional semiconductor with an intrinsic direct band gap, making it promising for practical applications in optoelectronic devices. In this work, ab-initio density functional theory (DFT) calculations were performed in order to study the possibility of manipulating the essential physical and chemical properties of TH-carbon by fluorination, which significantly change the hybridization states of carbon atoms. The phonon spectrum, abinitio molecular dynamics (AIMD) simulations, and elastic constants results revealed that fluorinated derivatives of TH-carbon are dynamically, thermally, and mechanically stable. Depending on the fluorine coverage, we examined the tunability of the electronic band gap and the direct-indirect-direct band gap transitions. We found that the phononic gap in TH-carbon can be controlled by fluorination. A decrease in the specific heat capacity was observed with increasing fluorine coverage, which is useful for nanoscale engineering of heat management. The fluorination is found to reduce the in-plane stiffness and Young’s modulus, but it increases the ultimate strength. These results suggest fluorination would enable the ability to tailor TH-carbon material for several interesting technological applications.