Theoretical investigation on electronic properties and carrier mobilities of armchair graphyne nanoribbons

Seven types of armchair graphyne nanoribbons are investigated with HSE06 functional. The quantum confinements in the graphyne nanoribbons open or increase the band gaps of the corresponding two-dimensional graphynes, which is crucial to high on/off ratio in electronic device operation. The major carrier mobilities of the graphyne nanoribbons with high percentage of sp hybridized carbon atoms are very large. The sparse linking pattern results in small number of frontier crystal orbitals and small deformation potential constants, which are responsible for the large carrier mobilities. Some graphyne nanoribbons have band gaps larger than 0.4 eV. Meanwhile, they have both high hole and electron mobilities. These benefit current complementary circuit with low power dissipation. Especially, the hole and electron mobilities of 14,14,18-graphyne nanoribbons are more than an order larger than those of the armchair graphene nanoribbons, indicating that they have potential applications in high speed electronic devices.