Hybrid solar cells (HSCs) can be a new pathway for low-cost, flexible, and high efficiency solar cells. III-V nanowires (NWs) with sub-wavelength scale dimensions have shown excellent optical and electrical properties, and can be easily fabricated on thin substrates together with polymer materials. In order to obtain optimal design requirements for III-V NWs/PEDOT: PSS HSCs, optical simulations using finite-difference-time-domain (FDTD) method is performed. To enhance light absorption properties of NWs, the important geometrical parameter, namely the diameter (D) of the NWs is optimized. Further, to maximize short-circuit current density, polymer (PEDOT: PSS) coating thickness on the NWs is optimized. In comparison to NW/air system, optimized PEDOT: PSS-coated NWs have shown better intrinsic anti-reflection properties, broad absorption spectra, and enhanced optical generation rates.