Researchers at Princeton University led by electrical engineer Stephen Chou, have developed what is being called a “nanostructure sandwich” to trap light and improve the efficiency of organic solar cells by 175%. A layer of metal mesh 30 nanometers thick (A nanometer is about one hundred-thousandth the width of human hair) is placed on top of layers of plastic materials, titanium oxide, and aluminum.
Chou says the mesh acts like a “black hole” for light, trapping it even more effectively when the light is indirect (as it is on cloudy days).
The Princeton team’s research is just one among many working to produce solar cells that can be produced at a low cost, but efficient enough to be marketable. Compared with photovoltaics, solar organic cells are cheap, but inefficient. Researchers at the University of Warwick, in England, have recently created an organic solar cell with a sufficiently high voltage to recharge a lithium-ion battery – this could translate into an ideal charging system for portable electronics. Researchers in Germany are working on printable organic solar cells.