The optical properties of graphene nanoribbon superlattices embedded in boron nitride sheets and the possibility of using such structures as photodetectors are studied. We propose a set of tight-binding parameters for the investigated structures which shows excellent agreement with first-principles results. The results indicate that the optical spectrum of a BN-confined AGNR superlattice contains more absorption peaks and show more optical intersubband transitions compared to a hydrogen passivated superlattice with the same geometry. Employing the non-equilibrium Green’s function method, the photocurrents and quantum efficiencies are evaluated and compared for both devices at various incident photon energies.
Using an statistical approach the role of line-edge roughness on the optical properties of GNR-based superlattices is investigated. The results indicate that the quantum efficiency and photoresponsivity decrease in the presence of line-edge roughness. For HSL, induced states appear and increase with the roughness amplitude which result in the appearance of an additional peak in photocurrent spectrum. In comparison with HSLs, BNSL photodetectors exhibit more robust optical properties in the presence of line- edge roughness due to stable edge atom configuration.