Unique Omnidirectional Negative Poisson’s Ratio in δ-Phase Carbon Monochalcogenides
Minglei Sun, Udo Schwingenschlögl
Abstract
Auxetic materials (negative Poisson’s ratio) are of exceptional importance for nanomechanical applications. Using first-principles calculations, we propose two-dimensional δ-phase carbon monochalcogenides (δ-CS, δ-CSe, and δ-CTe) with very strong auxeticity. In contrast to the known two-dimensional materials, we find that Poisson’s ratio is negative in all crystal directions. In addition, the δ-phase carbon monochalcogenides turn out to be direct or quasi-direct bandgap semiconductors with impressive absorption of solar radiation.
Topics & Concepts
AuxeticsPoisson's ratioMaterials sciencePoisson distributionPhase (matter)Condensed matter physicsBand gapOmnidirectional antennaSemiconductorCarbon fibersAbsorption (acoustics)OpticsOptoelectronicsPhysicsComposite materialQuantum mechanicsMathematicsComputer scienceTelecommunicationsStatisticsComposite numberAntenna (radio)2D Materials and ApplicationsMXene and MAX Phase MaterialsGraphene research and applications