Monday, July 08, 2013: A team of researchers at MIT has devised a technique to create solar cells that are just two molecules thick. Though the resultant solar cell can offer conversion efficiency of just 1-2 per cent, on placing multiple cells on top of the other, it is possible to increase the overall capacity, as compared to the conventional cells.
The latest trend in solar cell research has been on enhancing the conversion efficiency of solar cells. As a result, most solar cells can now generate 15 -20 per cent of the solar energy they get into electricity and the most efficient modules operate at 30 per cent efficiency level.
Researchers at MIT are now planning to turn their research into a new direction. They are now working on making the solar cells much thinner and use fewer materials. In their research paper titled “Extraordinary Sunlight Absorption and 1 nm-Thick Photovoltaics using Two-Dimensional Monolayer Materials” they have explained how they have developed a technique to create solar cells which are only two molecules thick- the thinnest possible solar cells reported so far.
As explained by Jeffrey Grossman, the Carl Richard Soderberg Associate Professor of Power Engineering at MIT, who authored the research paper along with Marco Bernardi, a postdoc in MIT’s Department of Materials Science, and Maurizia Palummo, a senior researcher visiting MIT from the University of Rome, described that they made use of nanotechnology to put a one-molecule thick layer of grapheme on top of a one-molecule thick layer of molybdenum disulphide to create a solar cell, which is just one nanometre thick.
Alta Devices is also working on developing an ultra-thin solar cell, and while their product also works at 30 per cent efficiency, it is 1,000 times thicker as compared to MIT’s cell. Also, the MIT cell will be cheap to produce as compared to Alta Devices’ which will be expensive as it involves the use of purified silicon.
