A leading photovoltaics expert in Israel has demonstrated how metallic wires mounted on conductive glass can form the basis of solar cells that produce electricity with efficiency similar to that of conventional, silicon-based cells - but are much cheaper to produce.
Professor Arie Zaban, Head of Bar-Ilan University's Nanotechnology Institute in Israel had in his earlier efforts produced photovoltaic cells just one square centimeter in size. He now claims that he has achieved a cell measuring ten by ten - something that he says will significantly boost its usefulness in technologies that seek to produce commercial amounts of solar power.
Initially, they created linked arrays of very small cells, which led to a loss of efficiency because the sunlight hitting the space between the cells was not converted to electricity. He says that their new design offers ten times more surface area, which means that more of the array is actively capturing the sun's energy making their new cell a practical choice for solar energy production.
Another of his recent discoveries brings costs down by economizing on platinum - an expensive metal embedded on the glass cell's surface. "We've found a way to produce platinum nanodots - tiny crystals measuring only a few nanometers in diameter. The highly reactive metal is an important part of the solar cells operation - Thanks to this technique now under consideration for a patent - we reduce the amount of platinum needed by a factor of 40," said Professor Zaban.
In his previous research, Professor Zaban pioneered a low-cost solar technology in which nano-sized particles of an inexpensive semiconductor material are arranged in a sponge-like array on top of flexible plastic sheets. Key to his system is the use of an organic dye that allows the semiconductor - transparent in its natural form - to absorb light.
Photovoltaics, which directly convert sunlight into electricity, include both traditional, polysilicon-based solar cell technologies and new thin-film technologies. Thin-film manufacturing involves depositing extremely thin layers of photosensitive materials on glass, metal, or plastics. While the most common material currently used is amorphous silicon, the newest technologies use non-silicon-based materials such as cadmium telluride.
Bar-Ilan has entered into partnership with Orionsolar, a Jerusalem-based company that is developing commercial applications for inexpensive, dye-based photovoltaics based on Professor Zaban's work.
According to the Professor the new solar cells will be available commercially within the next five years.
Reference Bar-Ilan University
Top image Professor Arie Zaban, Head of Bar-Ilan University's Nanotechnology Institute, courtesy of Bar-Ilan University
For more on photovoltaics attend the IDTechEx conference Photovoltaics Beyond Conventional Silicon.
