12
nanotimes
10-02 :: February 2010
Companies
Solar Cells //
Mitsubishi Electric Sets Two World Records in
Solar Cell Conversion Efficiency
M
itsubishi Electric Corporation (TOKYO:6503) One of the world records, which Mitsubishi Electric
has achieved a very high photoelectric has now renewed for the third consecutive year, is a
conversion efficiency of 14.8% in a 5mm x 5mm 19.3% efficiency rating for photoelectric conversi-
(0.1968inch) thin-film silicon photovoltaic (PV) cell. on of a practically-sized polycrystalline silicon PV
The thin-film silicon PV cell developed by Mitsubishi cell of 100 cm
2
(15.5 inch
2
) or larger, with the PV
Electric has a triple junction structure that utilizes a cell measuring approximately 15cm x 15cm x 200µm
majority of the solar spectrum for higher efficiency. (5.9inch x 5.9inch x 0.00787inch). The rating is 0.2
points higher than the company‘s previous record of
Mitsubishi Electric, however, has met a technological 19.1%.
breakthrough to achieve 14.8% photoelectric conver-
sion efficiency, according to its own evaluation, by The second world record, achieved with the same
using a triple-junction configuration in which the first technologies in an ultra-thin polycrystalline silicon
layer absorbs short wavelengths and the third layer PV cell measuring approximately 15 cm x 15 cm
absorbs long wavelengths, thereby enabling the use x 100 µm, is an efficiency rating of 18.1%, a
of a wide solar spectrum from visible light to infrared 0.7-point improvement over the company‘s previous
rays. Key technologies that help to make this possi- record of 17.4%.
ble include:
Previously, Mitsubishi Electric improved the conver-
• Semiconductor materials that tune to a particular sion efficiency of its PV cells by developing a low-
frequency of the spectrum; reflection, honeycomb-textured surface that reduces
• High-quality film-deposition processing for each sunlight loss due to reflection. Mitsubishi Electric also
layer; developed a reflective structure for the rear surfaces
• Texture fabrication applied to transparent of PV cells to capture infrared rays that otherwise
electrodes for optimal confinement of sunlight. would pass through the cells and thus not be har-
nessed to generate electricity. Using these techno-
Furthermore, Mitsubishi Electric Corporation has set logies, in 2009 Mitsubishi Electric achieved another
two world records for photoelectric conversion effi- world-record of 19.1 percent with a polycrystalline
ciency in polycrystalline silicon photovoltaic (PV) silicon PV cell measuring approximately 15 cm x 15
cells, achieved by reducing resistive loss in the cells. cm x 200 micrometers.
Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69