The periodically patterned Si nanopyramid solar cell shielded with SiNx-passivation layer was fabricated using nano-imprint method. The fabricated nanopyramid Si solar cell demonstrated the near-zero reflectivity over a wide range of wavelengths. With a SiNx-coating layer, nanopyramids showed 0.366% reflection. A SiNx-coated nanopyramid Si is efficient to improve the carrier collection for broad wavelengths due to intrinsically low light-reflection of Si nanopyramid structures. SiNx-passivation effectively controls carrier collection efficiencies of nanopyramid structures, resulting in significant improves short wavelength lights. We systematically investigated optical and electrical performances of nanoscale solar cells and suggest a route to realize high-efficient nanoscale solar cells. The importance and influence of SiNx-passivation layer and nanopyramid structure in Si based solar cell were explained in detail with optical and electrical characteristics. (C) 2016 Elsevier B. V. All rights reserved.