AN international team of researchers has developed organic solar cells that can convert up to 9.5 percent of the energy in sunlight to electricity, according to a new study published in the journal Nature Energy.
An organic solar cell is a type of photovoltaic cell made of conductive organic polymers, and is considered an advancement over typical silicon-based solar cells in that organic cells can be made much thinner and more flexible.
The researchers found that the organic solar cells they created required a significantly lower driving force and had faster charge separation than previous cells. The driving force is a measure of the energy that is used to split electron-hole pairs into free carriers. A high driving force results in the loss of the photovoltage, a key parameter for the solar cell. The lower the driving force, the higher the photovoltage.
It was previously believed that efficient operation of organic solar cells requires a large driving force, which limits the efficiency of organic solar cells, the study explained. However, having developed efficient organic solar cells with very low driving force, the study concluded, “This implies that the intrinsic limitations of organic solar cells are no greater than those of other photovoltaic technologies, bringing them a step closer to commercialization.”
“We have developed a system with a huge potential to increase the power conversion efficiency in organic solar cells,” said corresponding author Dr. Gao Feng from Linköping University in Sweden.