Sharp sets highest solar cell efficiency record

Sharp Corporation claims to have achieved the highest conversion efficiency of non-concentrator solar cell in the world. The conversion efficiency of 35.8 per cent was confirmed last month by the National Institute of Advanced Industrial Science and Technology.

Unlike silicon-made solar cells, oftentimes used for home solar panels, the new solar cell from Sharp utilizes many light absorbing layers made from compounds such as gallium and indium. Compound solar cells, mostly utilized for space satellites, are expensive to produce.

Germanium is usually used at the bottom layer of a triple junction solar cell. But germanium generates huge amount of current, which the majority cannot be used for electricity and is wasted. Sharp has worked a solution for this issue by outlining the bottom layer with Indium Gallium Arsenide (InGaAr), a material with higher light utilization efficiency.

As a result, the percentage of wasted current was lessened and Sharp has able to boost conversion efficiency of their solar cells to 35.8 per cent, from a previous record of 31.5 per cent in 2003. The company however points out that the results have been completed by using a one-centimeter cell, which means that the technology has not yet been integrated into satellites.

Being in the solar energy industry since 1967, Sharp began providing microcrystalline silicon modules for space applications. Sharp achieved 40 per cent conversion efficiency in 2007 for a triple junction compound concentration solar cell. The company also provides homes with solar cells that have conversion efficiency of about 13.7 per cent.