The optical responsivity in IR-photodetector based on armchair graphene nanoribbons with p–i–n structure

► Armchair graphene nanoribbons infrared photodetectors has been investigated. ► All three structural families of A-GNR have been investigated. ► All three structural families with different number of layers have been investigated. ► We have calculated the optical responsivity of A-GNR based IR photodetector. ► The effects of temperature, nanoribbon width and layers’ numbers have been analyzed. Armchair graphene nanoribbons (A-GNRs) are an alternative material to use in novel infrared photodetectors, because of their tunable energy gap in the infrared spectrum, and their high quantum efficiency. In this paper, an A-GNR p–i–n structure with all three structural families, different width, and different number of layers to use in IR detectors have been investigated. With calculating the band structure and energy gap using the tight-binding model and by including the edge deformation, the optical absorption in the single electron approximation has been obtained by calculating the optical conductance. Finally, we have calculated the quantum efficiency and the optical responsivity of A-GNR based IR photodetector as a function of incident photon energy, temperature, nanoribbon width and the number of layers. Results show that the responsivity of the A-GNR based IR photodetector increase by increasing the width and number of layers and decrease by increasing the temperature.