▎ 摘　　要

The unique electronic and optical properties of graphene nanoribbons (GNR) make it a potential material in the field of optoelectronics, such as in solar cell and photovoltaic (PV) applications. In this paper, we have demonstrated the effect of silicon (Si) atom doping and alloying in zigzag graphene nanoribbons (ZGNR). The effect of doping concentration and position of substitutional doping are the main criteria for modeling the electronic and optical properties of ZGNR. Doping concentrations of 3.12%, 12.50%, and 50.00% were used. Density functional theory-based calculations were performed to evaluate the geometrical stability, electron density, cohesive energy, quantum conductance, Mulliken population and density of states. Similarly, the optical properties were evaluated by considering the absorption coefficient for each Si-doped ZGNR. Further, the PV performance of each Si-doped ZGNR was analysed by evaluating the power conversion efficiency (PCE) and power density w.r.t. length and weight. Our results reveal that the Si atom shows stable bonding with the C atom of ZGNR and enhances the quantum conductance by 1.332 times. A significant enhancement in the absorption on the order of 10(4) times in comparison to pristine ZGNR over the UV and visible range is also observed. More significantly, the PV performance shows similar to 3 X 10(2) and similar to 5 X 10(2) times higher power density in comparison to GaAs and Si, respectively, and 1.14 times higher than graphene sheet. Finally, our work has broad application in designing a ZGNR-based solar cell with PV device performance.