Inverted silicon nanopencil arrays

This chapter begins with a comprehensive review of recently developed, simple, wet-chemistry-only fabrication scheme for the controllable hierarchy of nanopencil arrayed structures, followed by the detailed experimental and simulated results of their optical characteristics. It focuses on the future development of next-generation nanostructured silicon photovoltaics with optimized photovoltaic performances. The chapter demonstrates a facial and anisotropic wet-chemistry-only fabrication scheme for the controllable hierarchy of tapered silicon nanoarrays with different geometrical morphologies, ranging from nanorods, nanocones to nanopencils over large areas, which is particularly attractive for applications requiring large-scale, low-cost, and efficient light management. The light-trapping mechanism and corresponding design principle of inverted nanopencils will be thoroughly discussed as well in order to obtain insights into the technological potency of these pencil arrays as efficient photon harvesters for photovoltaics. Nanopencil arrays also offer such a mechanism to couple light into the silicon substrate with the suppressed top surface reflection of tapered tips.