Widely tunable band gaps of graphdiyne: an ab initio study
Abstract
Functionalization of graphdiyne, a two-dimensional atomic layer of sp–sp2 hybrid carbon networks, was investigated through first-principles calculations. Hydrogen or halogen atoms preferentially adsorb on sp-bonded carbon atoms rather than on sp2-bonded carbon atoms, forming sp2- or sp3-hybridization. The energy band gap of graphdiyne is increased from ∼0.5 eV to ∼5.2 eV through the hydrogenation or halogenation. Unlike graphene, segregation of adsorbing atoms is energetically unfavourable. Our results show that hydrogenation or halogenation can be utilized for modifying the electronic properties of graphdiyne for applications to nano-electronics and -photonics.