Effect of vacancy in penta-graphene nanoribbons: A first principals study

Penta-graphene has been proposed recently as a new stable carbon allotrope which is mechanically stronger than graphene. To future explore its properties, we use the first-principals calculations to reveal that the electronic properties of penta-graphene nanoribbons can be modified in the presence of vacancy defect. Our calculations showed that the band gap of penta-graphene nanoribbons changes with changing the width of the ribbons and on the position of the vacancy relative to its edge. The vacancy formation energy is calculated to be 8.42 eV in the middle of the ribbons and decreases to 6.8 eV when the vacancy position is close to the edge of the ribbon. These results for a stable nanoribbon with a large band gap is promising for designing optoelectronic devices.