Nitrogen-tailored quasiparticle energy gaps of polyynes

Polyyne, an sp 1 -hybridized linear allotrope of carbon, has a tunable quasiparticle energy gap, which depends on the terminated chemical ending groups as well chain length. Previously, nitrogen doping was utilized to tailor properties different kinds carbon. However, how tailors polyyne remains unexplored. Here, we applied GW method study gaps N-doped polyynes with lengths. When C atom is substituted by N in polyyne, gap varies position polyyne. The modification particularly pronounced when second-nearest-neighboring carbon hydrogen substituted. In addition, makes Fermi level closer lowest unoccupied molecular orbital, resulting n-type semiconductor. Our results suggest another route electronic addition length and groups.