Joined: 16 Mar 2004
|Posted: Mon May 11, 2009 3:31 pm Post subject: Solar Cell Efficiency Hits a Record High
|Dutch scientist Bram Hoex and his Technische Universiteit Eindhoven colleagues have managed to increase the efficiency of an important type of solar cell from 21.9 to 23.2 percent. This world record was presented on Wednesday 14 May, at a large conference on solar energy in San Diego ( USA ).
The efficiency improvement brings us one step closer to the breakthrough of solar energy. An improvement of more than one percent may seem modest, yet it can yield millions for solar cell producers. According to Hoex' calculations the improvement can increase the yield of a production line for solar cells by five million per year. Expectations are that the application of the ultra-thin film will cost far less.
Crystalline silicon solar cell.
An application of an ultra thin film of Al2O3 markedly increases its efficiency.
Hoex applied an ultra-thin film of aluminum oxide (circa thirty nanometers) on the front of a crystalline silicon solar cell. This film has an unprecedented high number of built-in negative charges, which ensure that the loss of energy on the surface – which is normally considerable - disappears. Of all the solar light falling onto the solar cell, 23.2 percent is now converted into electric energy. That used to be 21.9 percent.
Hoex gained his PhD on 8 May within the TU/e Department of Applied Physics. In the Plasma & Materials Processing (PMP) research group he was supervised by professor Richard van de Sanden and Erwin Kessels. The specialty of this group is the application of extremely thin layers by means of plasmas. The flimsy aluminum oxide film, developed within the PMP group, may lead to a technological innovation in the field of solar cells. A number of major manufacturers of solar cells have already showed an interest.
The research was conducted in collaboration with the German Fraunhofer Institute. Part of Hoex' work was paid for by the government, as the industrial application of this type of high-efficiency solar cell is coming considerably closer as a result.
Solar cells have for years looked like a highly promising way to partly solve the energy problem. The sun rises day after day, and solar cells can conveniently be installed on surfaces with no other useful purpose. Solar energy also offers opportunities for use in developing countries, many of which have high levels of sunshine. Within ten to fifteen years the price of electricity generated by solar cells is expected to be comparable to that of ‘conventional' electricity from fossil fuels. This technology breakthrough now brings the industrial application of this type of high-efficiency solar cell closer. For this reason, part of Hoex's PhD research project was paid for by three Dutch ministries: Economic Affairs; Education, Culture and Science; and Housing, Spatial Planning and the Environment.