15%! U.S. organic solar cell photoelectric conversion rate hits a record

According to a recent report from the US Daily Science website, scientists at the University of Michigan in the US demonstrated an organic solar cell with a photoelectric conversion efficiency of 15%. The new results will further promote the commercial use of more flexible and cheaper solar cells. Researchers estimate that if the photoelectric conversion efficiency of organic solar cells can reach 15%, and the service life reaches 20 years, then the power generation cost is only 7 cents per kilowatt hour. According to data from the US Energy Information Administration, in 2017, the average cost of electricity generation in the United States was 10.5 cents per kilowatt hour. Organic solar cells have many advantages over traditional inorganic cells. Silicon-based inorganic solar panels are expensive to manufacture, but carbon-based organic solar cells can be cheaply manufactured into rolls, these rolls are thin enough to bend and twist in buildings or clothing, and can be made into any color, even transparent, So as to match the surrounding environment. However, the photoelectric conversion efficiency of organic solar cells is relatively low, and they can only be resigned to the competition with ordinary energy. The lead author of the study, Xiaozhou Che (transliteration), said: 'In the past few years, its photoelectric conversion efficiency has been hovering around 11% to 12%.' In order to make a breakthrough, the researchers assembled a number of advancements in design and technology. First, they designed a system that combines dedicated layers to absorb visible and infrared light. In essence, they stacked two organic solar cells-one can absorb light in the visible spectrum starting at 350 nanometers; the other can absorb near-infrared light with wavelengths up to 950 nanometers. Che Xiaozhou said: 'The photoelectric conversion efficiency of the battery itself is 10% to 11%. When they are stacked together, the light absorption increases. In addition, we also use an anti-reflective coating to increase the efficiency to 15%.' The team also proved that their new designs, materials and processes have a yield rate of over 95%, which is very important for extending the manufacturing process to an industrial level. Researchers believe that transformation efficiency can be further improved. Che Xiaozhou explained: “Improve light absorption to increase current and minimize energy loss, thereby increasing voltage. The calculation results show that the photoelectric conversion efficiency of this type of equipment can reach 18% in the near future, which is helpful. Solar energy has become a truly ubiquitous clean energy.'