Silicon Filaments in Silicon Oxide for Next-Generation Photovoltaics.
The group of Christophe Ballif (PV-LAB - Photovoltaics and Thin Film Electronics Laboratory ) demonstrate, on the basis of advanced TEM techniques, a new, mixed phase Si/SiO2 material, which they call filamentous SiOx. Nanometer wide silicon filaments embedded in an amorphous silicon oxide matrix are grown at low temperatures over a large area. The optical and electrical properties of these mixed-phase nanomaterials can be tuned independently, allowing for advanced light management in high efficiency thin-film silicon solar cells and for band-gap tuning via quantum confinement in third-generation photovoltaics. The independently tunable electrical and optical properties of this material allow for new ways of increasing the efficiency of Si-based second generation photovoltaics. The fabrication of this material is scalable, and it uses low-cost production processes and abundant raw materials, thus improving the chances of large-scale photovoltaic deployment for energy production. Looking forward to third generation photovoltaics, the increased flexibility in tailoring the Si particles and the low temperature fabrication process might help to overcome the present limitations for production of quantum confinement based devices.
Peter Cuony et al., Advanced Materials, DOI: 10.1002/adma.201104578 (2012)