Kilic, Mehmet Emin Lee, Kwang-Ryeol 2024-01-19T11:32:27Z 2024-01-19T11:32:27Z 2022-06-23 2022-08 0008-6223 https://pubs.kist.re.kr/handle/201004/114835 The great success of graphene has encouraged tremendous interest in searching for new two-dimensional (2D) carbon allotropes. Based on first-principles calculations, we proposed new 2D carbon allotropes obtained from the assembly of fenestrane molecule unit, named as four-penta-graphenes (fPG). The fPG monolayers are energetically more favorable than pentagraphene and show excellent dynamical, thermal, and mechanical stability. They exhibit exotic mechanical properties including anisotropic in-plane stiffness and auxetic behavior with sign-tunable Poisson's ratio. Their electronic properties are diverse, ranging from narrow band gap semiconductors to metal. The electronic band gap and band edge positions of the fPG semiconductors can be flexibly modulated by strain engineering. Indirect-to-direct band gap and semiconductor-to-metal transitions can be achieved by applying compressive and tensile strains, respectively. High mobility and anisotropic effective mass of carriers make these materials promising for nanoelectronics. Using many-body GW0 thorn BSE approximations, we reveal that the fPG semiconductors exhibit strong excitonic effects with distinct optical absorption peaks in the visible range. These remarkable optical properties make them also promising devices for optoelectronics. (C) 2022 Elsevier Ltd. All rights reserved. English Pergamon Press Ltd. Four-penta-graphenes: Novel two-dimensional fenestrane-based auxetic nanocarbon allotropes for nanoelectronics and optoelectronics Article 10.1016/j.carbon.2022.04.018 1 Carbon, v.195, pp.154 - 164 Carbon 195 154 164 N scie scopus 000804384200003 Chemistry, Physical Materials Science, Multidisciplinary Chemistry Materials Science Article GRAPHENE ALLOTROPE CARRIER MOBILITY BAND-GAP CARBON GRAPHYNE PREDICTIONS GRAPHDIYNE CARBIDES