Tuning Penta-Graphene Electronic Properties Through Engineered Line Defects

Penta-graphene is a quasi-two-dimensional carbon allotrope consisting of a pentagonal lattice in which both sp(2) and sp(3)-like carbons are present. Unlike graphene, penta-graphene exhibits a non-zero bandgap, which opens the possibility of its use in optoelectronic applications. However, as the observed bandgap is large, gap tuning strategies such as doping are required. In this work, density functional theory calculations are used to determine the effects of the different number of line defects of substitutional nitrogen or silicon atoms on the penta-graphene electronic behavior. Our results show that this doping can induce semiconductor, semimetallic, or metallic behavior depending on the doping atom and targeted hybridization (sp(2) or sp(3)-like carbons). In particular, we observed that nitrogen doping of sp(2)-like carbons atoms can produce a bandgap modulation between semimetallic and semiconductor behavior. These results show that engineering line defects can be an effective way to tune penta-graphene electronic behavior.