Swiss Federal Institute of Technology in Lausanne (EPFL) researchers are developing solar cells with higher efficiency thanks to a new nanopatterning technology for the zinc oxide layer.
September 13, 2011 — Swiss Federal Institute of Technology in Lausanne (EPFL) researchers are developing solar cells with higher efficiency thanks to a new nanopatterning technology for the zinc oxide (ZnO) layer. The solar cells are 1000x thinner than conventional cells.
The thin-film solar cells under development by Professor Christophe Ballif’s team at the Photovoltaics and Thin-Film Electronics Laboratory at the EPFL use thin silicon layers with zinc oxide to scatter light onto the silicon.
Zinc oxide layers grow in small pyramid-shaped crystals, which the researchers are modifying for better light scattering. They grew ZnO on an inverted mold built in the structure they wanted. The thin layer is then deposited by inverting the mold.
|Figure. Zinc oxide layers seen through an electronic microscope. Left: natural pyramid structure. Right: structure when grown on a mold (height: 5µm).|
The new ZnO manufacturing method increases the light trapped onto the silicon layers of the photovoltaic cell. It is compatible with mass production methods, raising the possibility of a lower fab cost with this technology. The material is also readily available and nontoxic.
The procedure is described in the September edition of the journal Nature Photonics. Access it here: http://www.nature.com/nphoton/journal/v5/n9/full/nphoton.2011.198.html
The work was supported by the Swiss National Science Foundation and the Federal Office of Energy.