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

Abstract

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 C₂N_1−xP_x and C₂N_1−xAs_x alloys are easier to fabricate than C_2−xSi_xN and C_2−xGe_xN alloys. Moreover, it is feasible to construct mixed C₂N_1−xP_x and C₂N_1−xAs_x 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 C₂N_1−xP_x and C₂N_1−xAs_x alloys may be promising candidates for optoelectronic applications.