Alternative Energy enewsletter, October 29th, 2009
Sharp Solar We still have to miles to cover before solar power can replace the fossil fuels and become a cheap and effective solution for common folks. But it is indisputable that sun is the single greatest fuel source we can harness to our advantage. Solar energy can leave its impact on a global scale in a significant manner. Everyone who is blessed with a hot, sunny spot by the grace of the nature could one day power their homes entirely by photovoltaic roofs. Even it seems possible that large solar arrays could feed power plants that keep the lights on in entire municipalities.
Sharp Corporation’s technical team has come up with an impressive solar power development. Though its nothing new for the research and development team as they often come up with solar gadgets from televisions to mobile phones. This time the Sharp broke the solar conversion efficiency record. According to the company, it’s a title-holding 35.8 percent cell conversion efficiency with the help of a triple-junction compound cell. Sharp team has been working on this project since 2000.
These compound cells are chiefly used on satellites. The triple-junction cell has a group of three photo-absorption layers and it uses indium gallium or arsenide to boost efficiency. To boost the efficiency of triple-junction compound solar cells, it is important to improve the “crystallinity” in each photo-absorption layer. Sharp has successfully formulated an InGaAs layer with high crystallinity by using its unique technology for forming layers. The whole exercise resulted in the formation of layers that minimized waste and hitting a record conversion efficiency of 35.8%. Hopefully this kind of technology will trickle down to the consumer market too.
If everything goes right with this project then solar power will lose its just some pie-in-the-sky image. Solar power will emerge as effective power source sooner than expected. Still solar cells are being used in a variety of products but developments like 35.8 percent efficiency attaches wings to clean and green energy sources. Sharp’s triple-junction compound cell just broke a world record by showing a 35.8% cell conversion efficiency.
To boost the efficiency of triple-junction compound solar cells, it is important to improve the crystallinity (the regularity of the atomic arrangement) in each photo-absorption layer (the top, middle, and bottom layer). It is also crucial that the solar cell be composed of materials that can maximize the effective use of solar energy. Traditionally, germanium is used as the base layer due to its ease of manufacturing. However, if we care to look from the view of performance, even though germanium produces a large amount of current, the majority of the current is wasted, without being used effectively for electrical energy. How to get rid of this significant hurdle? The answer to this problem was to form the bottom layer from InGaAs (indium gallium arsenide), a material with high light utilization efficiency. However, it is quite difficult to produce high-quality InGaAs with high crystallinity.
Sharp has overcome this hurdle of forming an InGaAs layer with high crystallinity by making use of its proprietary technology for forming layers. The end desirable result is the amount of wasted current has been reduced to minimum and the conversion efficiency, which had been 31.5% in Sharp’s previous cells, has been successfully increased to 35.8%