Energy bandgap engineering of graphene nanoribbon by doping phosphorous impurities to create nano-heterostructures: A DFT study

Energy bandgap engineering is used to produce semiconductor heterostructure systems that perform processes such as the resonant tunneling in nanoelectronics and the solar energy conversion in solar cell applications. However, the performance of such systems degrades as their size is reduced. Graphene-based nanoelectronics has appeared as a candidate to enable high performance down to the single-molecule scale. Here, graphene nanoribbons (GNRs) can have bandgaps that are tunable by using chemical doping method. We have been predicted that bandgap engineering within a GNR may be achieved by varying the number and geometrical pattern of phosphorus (P) impurities in the GNS, so that we have carried out first-principles calculations of the energetic and electronic properties of P-doped GNR based on density functional theory (DFT) with Gaussian 09W packages. The geometric and electronic properties of the GNR with and without various dopants of phosphorus impurities were performed and discussed. Our results show that the electronic properties of GNR do not only depend on the phosphorus impurity concentrations, but also depend on the geometrical pattern of phosphorus impurities in the GNR. As a result, we can bandgap engineering of GNR by doping phosphorous impurities to create semiconductor heterostructure, which can be used in many important applications.