Modulation of the band structures and optical properties of holey C2N nanosheets by alloying with group IV and V elements

The band structures and optical characteristics of group IV (Si, Ge) and V (P, As) element-alloyed C2N monolayers are investigated by means of first-principles methods. The results indicate that C2N1-xPx and C2N1-xAsx alloys are easier to fabricate than C2-xSixN and C2-xGexN alloys. Moreover, it is feasible to construct mixed C2N1-xPx and C2N1-xAsx alloys with tunable composition and band gap. When the doping concentration increases, the band gap shows a decreasing tendency, and the absorption edges exhibit a red shift in these alloys. These obtained results predicate that C2N1-xPx and C2N1-xAsx alloys may be promising candidates for optoelectronic applications.