Preparation of hybrid silicon wire and planar solar cells having ZnO antireflection coating by all-solution processes

This report proposes newly designed all-solution based processes for fabricating hybrid silicon (Si) wire-planar solar cells having conformal zinc oxide (ZnO) nanorod anti-reflection coating (ARC). The all-solution processes were composed of three steps. First, metal-assisted chemical etching combined with natural lithography was used to fabricate ordered Si wire arrays. Second, spin-on-dopant (SOD) diffusion was introduced to make a pn junction in the Si wire arrays and bulk Si substrate. Finally, using hydrothermal synthesis, ZnO nanorods were grown on hybrid Si wire-planar solar cells to create an efficient ARC. Currentvoltage (IV) results show that the hybrid solar cells with ZnO ARC lead to increased power conversion efficiency by more than 25% compared to the planar solar cells. This is mainly attributed to the enhanced light absorption and reduced light reflection by the combination of Si wire geometry and ZnO ARC. This research demonstrates a new approach for lowering the cost of Si wire-based solar cells and making them applicable to photovoltaic devices with large areas.