Mechanical, Electronic, and Optical Properties of 8-16-4 Graphyne: A 2D Carbon Allotrope with Dirac Cones
Raphael M. Tromer, Marcelo Lopes Pereira, K. A. L. Lima, Alexandre F. Fonseca, L. R. da Silva, Douglas S. Galvão, Luiz Antônio Ribeiro
Abstract
Graphene’s success has led to the theoretical prediction and experimental synthesis of various 2D carbon-based allotropes. To explore the mechanical, structural, electronic, and optical properties of 8-16-4 graphyne, we employed density functional theory using the GGA/PBE approach, ab initio molecular dynamics (AIMD), and classical reactive molecular dynamics simulations. Our AIMD results indicate that this material demonstrates excellent dynamical and thermal stabilities. It has a formation energy of −8.57 eV/atom and an elastic moduli of 262.37 GPa. Regarding its band structure, this graphyne analogue is a semimetal with two Dirac cones. It also exhibits transparency and intense optical activity in the infrared region. Notably, the band structure of 8-16-4 graphyne remains practically unchanged at moderate strain regimes. To our knowledge, this is the first known 2D carbon allotrope to exhibit such behavior.