Study of structural, electronic, and mechanical properties of pure and hydrogenated multilayer penta-graphene nano-plates using density functional theory

Penta-graphene, a new carbon allotrope, has been proposed recently with excellent electronic properties and great potential for meta-materials or auxetic materials. However, the mechanical behaviors of pure and hydrogenated multi-layer penta-graphene have not been fully explored yet. In this work, the ab initio study is performed to evaluate the electronic and mechanical properties of multilayer penta-graphene in the presence and absence of hydrogen atoms. The effect of increasing the number of layers on the electronic, deformation mechanism and mechanical properties of penta-graphene is studied using Siesta package. The present simulations show that pure penta-graphene is a semiconductor with a quasi-direct band gap. As the number of layers increases, the band gap value has a decreasing trend and by adding the hydrogen atoms, an insulator-semiconductor phase transition occurs. Our findings reveal that pure monolayer and multilayer pentagraphene are converted to biphenylene structure, by increasing the uniaxial strain. However, penta-graphene in the presence of hydrogen atoms does not undergo structural transformation under strain. These results are expected to be useful for the practical applications of penta-graphene in nano-electronic devices.