Nanopillar photovoltaics: Materials, processes, and devices

Nanopillar photovoltaics present significant potential for fabrication of high-efficiency, low-cost solar cells. The advantages over planar cells, including wider materials choice, device geometries, and enhanced optical and electronic properties have been studied in detail over the past decade. Specifically, the 3-D geometry enables optimization of carrier collection and reduction of the material quality constraints. Furthermore, the anti-reflective and light trapping properties enable a drastic reduction in material necessary to absorb the majority of the incident light. Together, the optical and electronic advantages allow solar cell fabrication on low-cost substrates. However, the choice of the material system is important for taking advantage of the unique properties of nanopillar cells, especially given large surface/interface area. This review focuses on the recent work on the optical and electronic properties of nanopillar photovoltaics and the fabrication processes utilizing low-cost substrates. (C) 2011 Elsevier Ltd. All rights reserved.