According to the US Daily Science website, scientists from the University of Michigan have demonstrated that organic solar cells have a photoelectric conversion efficiency as high as 15%. The new results will further promote the commercial use of more flexible and cheaper solar cells.
The researchers estimate that if the organic solar cell's photoelectric conversion efficiency can reach 15% and its service life reaches 20 years, then the cost of generating electricity is only 7 cents per kilowatt-hour. According to the US Energy Information Administration, 2017, The average power generation cost in the United States is 10.5 cents per kilowatt-hour.
Organic solar cells have many advantages over traditional inorganic batteries. Silicon-based inorganic solar panels are costly to manufacture, but carbon-based organic solar cells can be made cheaply into rolls that are thin enough to be used in buildings or clothing. It bends and twists inside and can be made in any color, even transparent, to match the surrounding environment.
However, the photoelectric conversion efficiency of organic solar cells is relatively low, and they can only take a downswing in the competition with ordinary energy sources. The first author of the research, Car Xiaozhou, said: 'In the past few years, its photoelectric conversion efficiency has been hovering at 11% to 12%. % or so. '
In order to make breakthroughs, researchers gathered a number of advances in design and process. First, they designed a system that combines a dedicated layer 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 in wavelength; the other can absorb near-infrared light at wavelengths up to 950 nanometers. Cha 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 have also used anti-reflective coatings to increase the efficiency to 15%. ' The team also proved that their new design, material and process manufacturing yield up to 95% Above, this is very important for extending the manufacturing process to the industrial level.
The researchers believe that the conversion efficiency can be further improved. Che Xiaozhou explained: 'You can increase the current by improving light absorption, and minimize the energy loss, thereby increasing the voltage. Calculation results show that the photoelectric conversion efficiency of such equipment In the near future, up to 18% will help make solar energy a truly ubiquitous source of clean energy.
The research was published in the latest issue of Nature & Energy magazine.
