Organic solar cells exhibit record efficiency
In a progress that makes a more flexible, economical type of solar cell commercially feasible, researchers at the University of Michigan have showcased organic solar cells that can attain 15% efficiency. This level of efficiency is in the variety of many solar panels, or photovoltaics, presently available.
"Organic photovoltaics can potentially cut way down on the total solar energy system cost, making solar a truly ubiquitous clean energy source," said Stephen Forrest, the Peter A. Franken Distinguished University Professor of Engineering and Paul G. Goebel Professor of Engineering, who guided the new research published in Nature Energy.
Organic solar cells include carbon into their structure to offer several benefits over conventional "inorganic" cells. Silicon-based inorganic solar panels are expensive to manufacture—made up of thick, stiff sheets that require fixed installation points. But carbon-based organic solar cells could be economically manufactured in rolls that are quite to facilitate bending and curving around structures or within clothing and made in any color, even transparent, to merge with their environment. Despite these benefits, organic solar cells have been deficient in the efficiency needed to contend with conventional energy sources.
To address this shortcoming, the team developed a system that integrates specialized layers to absorb both visible and infrared light. In spite of setting record efficiency, the researchers believe they can scale their progress even more. The design is also scalable for industrial use.
At 15% efficiency and given a 20-year lifetime, the new solar cells could yield electricity at a cost less than 7 cents per kilowatt-hour. According to the US Energy Information Administration, the average cost of electricity in the US was 10.5 cents per kilowatt-hour in 2017.