Nanophotonics for ultra-thin crystalline silicon photovoltaics (PHOTONVOLTAICS)

Research Project, 2012 – 2015

The ambition of PhotoNvoltaics is to enable the development of a new and disruptive solar cell generation resulting from the marriage of crystalline-silicon photovoltaics (PV) with advanced light-trapping schemes from the field of nanophotonics. These two technologies will be allied through a third one, nanoimprint, an emerging lithography technique from the field of microelectronics. The outcome of this alliance will be a nano-textured thin-film crystalline silicon (c-Si) cell featuring a drastic reduction in silicon consumption and a greater cell and module process simplicity. It will thus ally the sustainability and efficiency of crystalline silicon PV with the simplicity and low cost of the current thin-film solar cells. The challenge behind PhotoNvoltaics lies behind the successful identification and integration of these nano-textures into thin c-Si-based cells, which aim is a record boost of the light-collection efficiency of these cells, without harming their charge-collection efficiency.The goals of this project are scientific and technological. The scientific goal is two-fold: (1) to demonstrate that the so-called Yablonovitch limit of light trapping can be overcome, with specific nanoscale surface structures, periodic, random or pseudo-periodic, and (2) to answer the old question whether random or periodic patterns are best. The technological goal is also two-fold: (1) to fabricate thin c-Si solar cells with the highest current enhancement ever reached and (2) to demonstrate the up-scalability of this concept by fabricating patterns over industrially relevant areas. To reach these goals, PhotoNvoltaics will gather seven partners, expert in all the required fields to model and identify the optimal structures, fabricate them with a large span of techniques, integrate them into solar cells and, finally, assess the conditions of transferability of these novel concepts, that bring nanophotonics into PV, further towards industry.