We present a comprehensive first-principles investigation of three novel two-dimensional carbon allotropes: alpha-, beta-, and gamma-TODD-Graphene (TODD-G), composed of 3-8-12-16, 3-8-12-16, and 3-4-8-12 interconnected carbon rings with sp/sp2 hybridization, respectively. Structural optimization, phonon spectra, and ab initio molecular dynamics simulations confirm their thermal and dynamical stability. All phases exhibit metallic electronic behavior, with distinct Dirac-like features and tilted Dirac cones that suggest anisotropic charge transport. Mechanical analysis reveals tunable anisotropy: alpha-TODD-G is strongly anisotropic, beta-TODD-G shows moderate anisotropy, and gamma-TODD-G displays an almost isotropic mechanical response. Optical spectra further differentiate the phases, with gamma-TODD-G showing strong absorption in the infrared region, while alpha- and beta-TODD-G mainly absorb in the visible and ultraviolet ranges.
@article{arxiv.2508.05013,
title = {Alpha-, Beta-, and Gamma-TODD-G: Novel 2D Planar Carbon Allotropes},
author = {Kleuton A. L. Lima and Jose A. S. Laranjeira and Alysson M. A. Silva and Bill. D. Aparicio-Huacarpuma and Fabrício M. Vasconcelos and Julio R. Sambrano and Douglas S. Galvão and Luiz A. Ribeiro Junior},
journal= {arXiv preprint arXiv:2508.05013},
year = {2025}
}