With all of the different types of solar cells being developed from thin-film to crystalline silicon as well as new ways of boosting light absorption it seems there is always a new solar cell efficiency record being announced, but this new record from Sharp of 43.5% is a pretty big deal. A large jump over the company's previous record of 36.9% efficiency in November 2011, it shows that solar technology is getting ever closer to that 50% mark that could revolutionize the industry.
Sharp achieved the conversion efficiency record with their concentrator triple-junction compound solar cell that uses a lens-based system to focus sunlight on the cells to generate electricity.According to Sharp:
Compound solar cells utilize photo-absorption layers made from compounds consisting of two or more elements, such as indium and gallium. The basic structure of this latest triple-junction compound solar cell uses Sharp’s proprietary technology that enables efficient stacking of the three photo-absorption layers, with InGaAs (indium gallium arsenide) as the bottom layer.
To achieve this latest increase in conversion efficiency, Sharp capitalized on the ability of this cell to efficiently convert sunlight collected via three photo-absorption layers into electricity. Sharp also optimized the spacing between electrodes on the surface of the concentrator cell and minimized the cell’s electrical resistance.
Conventional solar panels that are on the market now still have an efficiency of only about 15 to 20 percent, but these breakthroughs made in labs will eventually lead to climbing efficiencies in mass market solar panels too. Sharp's compound solar cell technology is currently only used in space satellites, but the company wants to adapt the technology into small-surface-area solar cells that would be practical for use down here on the ground.
The conversion efficiency record was confirmed by the Fraunhofer Institute for Solar Energy in April 2012 and it is the same exact conversion efficiency achieved by Solar Junction of the United States in March 2011. The fact that two companies have been able to achieve the same high efficiency is a good sign that the industry is quickly scaling up efficiency across the board.