Phhgraphene: An Anisotropic Dirac Material with Intrinsic Self-Doping Features and a Tunable Band Structure

Abstract

Two-dimensional (2D) Dirac cone materials have important prospects in highperformance electronic devices due to their unique electronic structure. In this study, we propose a 2D carbon allotrope sheet named "phhgraphene" based on first-principles calculations. Both phonon dispersion and molecular dynamics simulations were employed to verify the dynamic and thermal stabilities of phhgraphene. Remarkably, phhgraphene exhibits a pristine self-doping Dirac cone, which enhances the realization of high-speed carriers. The Fermi velocities are of the same order of magnitude as those of graphene. The self-doping feature can be easily regulated by applying a uniaxial strain. Additionally, under biaxial-shear strain, the electronic band structure of phhgraphene can be tuned from a semimetal to a semiconductor. Moreover, we systematically investigated the electronic band structures of phhgraphene nanoribbons and phh-nanotubes. The results indicate that phhgraphene nanoribbons exhibit a direction-dependent electron band structure, while the electronic energy band of phhnanotubes depends on chirality. Overall, our findings suggest that the high-performance electronic properties of phhgraphene make it a promising candidate for electronic devices.