Metallic nanoparticles can direct light better into the solar cell and prevent light from escaping. In conventional 'thick-film' solar cells, the nanoparticles would have little effect because all the light is absorbed by the film due to its thickness. For thin films, however, the nanoparticles can make a big difference.
Green is the most efficient "semi-transparent" colour for producing electricity, although red and purple also work well.
Oxford PV predicts that manufacturing costs of its product will be around 50% less than the current lowest-cost thin film technology and expects its new mechanism will eventually match the unsubsidised cost of electricity generated from fossil fuels.