Dresden 2020 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 45: Computational Materials Modelling - Low dimensional systems

MM 45.4: Talk

Wednesday, March 18, 2020, 18:00–18:15, IFW B

sp3 Bonded 2-Dimensional Allotrope of Carbon: A First-Principles Prediction — •Bikram Kumar Das, Dipayan Sen, and Kalyan Kumar Chattopadhyay — Thin Film and Nanoscience Laboratory, Department of Physics, Jadavpur University, Kolkata, India

In this work, using state-of-the-art theoretical calculations, we considered cyclobutane motifs, and investigated whether a sp3 bonded 2-dimensional carbon allotrope could be achieved by assembling ladderane chains. Energetic and dynamic stability studies yielded two such promising structures: one with 4-coordinated carbon atoms, space group PMMA, and a relatively more stable structure with a combination of 3 and 4-coordinated carbon atoms, space group P2/C; both having puckered geometries and partially sp3 C-C bonds. However thermal stability investigations indicated only the lower energy configuration could be stable at ambient temperature and pressure. Electronic structures of the proposed allotropes were studied with density functional theory at rigorous HSE06 level. Investigation of electronic properties of these proposed materials revealed them to be direct-gap semiconductors with small bandgaps. Under in-plane biaxial compressive strains, bandgaps of both were found to decrease; whereas, under similar tensile strains, bandgaps of both were observed to increase up to a strain limit of 5% and 6% for Phase 1 and 2 respectively.The predicted small bandgap values of the proposed allotropes, and especially their convenient tunability is thus highly promising from the perspective of next-generation carbon based microelectronics applications.