We propose a composited polycrystalline Si nanocorals (NCLs) solar cell with p-n active layer that integrated with CdS quantum dots (QDs). The composited solar cell achieved 22.6% improvement in power conversion efficiency (PCE), compared to the bare Si substrate. As studied by effective minority-carrier lifetime, photoluminescence and reflectance, the improvement of PCE contents two parts. Firstly, the prominent light trapping of Si NCLs with proper depth would dominant over the surface recombination velocity. Secondly, as the CdS QDs on the topside, the remarkable antireflection, passivation and down-conversion properties would contribute to a further enhanced PCE. (C) 2014 Elsevier B.V. All rights reserved.