Organic solar cells retain 93% power-conversion efficiency with new additive
A study conducted by Penn State University researchers has revealed that organic solar cells could be strengthened by adding a chemical additive, making them suitable for large-scale deployment and manufacturing. The study was reported on the official university website on February 16.
Assistant Professor Nutifafa Doumon and doctoral candidate Souk Yoon “John” Kim, both from the Department of Materials Science and Engineering, led this experiment.
The paper was recognized in ACS Materials Au’s “2025 Rising Stars in Materials Science” issue, which will be published this month.
Manufacturing silicon solar panels consumes massive amounts of energy and requires the use of toxic chemicals, creating recycling challenges. On the other hand, lower-impact organic cells made with less harmful materials don’t last long enough for large-scale deployment.
The researchers revealed that a new form of carbon-hydrogen compound could help strengthen these organic solar cells and make them a viable alternative for large-scale use.
The new chemical additive
The research focuses on the new chemical, the solid additive 9,10-phenanthrenequinone (PQ). In the aftermath of the experiments, this hydrocarbon derivative was found to possess environmentally friendly characteristics for stabilizing and strengthening organic solar cells.
Also known as organic photovoltaics, the hydrocarbon-based technology can quickly degrade its ability to convert solar energy into electricity.
“PQ is also low-cost, commercially available, safer, and simpler than many existing additives introduced in the manufacturing process. Better stability is a must for organic solar cells to become a more competitive option in the commercial market,” said Kim.
He revealed that incorporating PQ could offer a practical pathway to create sustainable, scalable, and durable alternative photovoltaics.
The process walkthrough
The researchers began the process by creating organic cells with varied structures and different additives in Doumon’s lab at University Park.
The cells were tested across parameters such as longevity, resilience, and efficiency under different temperatures and environmental conditions. The aim was to evaluate these cells’ ability to convert light energy over time.
Post the experiment, the researchers noticed that PQ improved the cell efficiency in addition to longevity. Cell efficiency is the fraction of incident light energy converted to electricity. They added the chemicals to the cell’s active layer, the part that absorbs sunlight.
An aftermath with strong data
The study highlighted the experiment’s potential reliability, with strong numbers supporting its hypothesis.
PQ helped organic solar cell devices retain more than 93% of their original power conversion efficiency under sustained heat for 180 hours. Usually, devices achieve only 76% retention with a commonly used toxic additive after 180 hours of use.
Even small stability improvements can reduce how often organic solar cells need to be replaced, cutting waste and costs, the researchers said. Organic cells are usually more flexible, lighter, and cheaper to make than silicon ones, but they also have much shorter lifespans.
The road ahead
“We’re not claiming that PQ solves all the problems,” Doumon said, hinting at more experiments in the future.
“Our findings are one step forward. We’re looking at other solid additives for further study, to see where PQ falls in a broader spectrum of options,” he added.
The research paper was published in the journal ACS Materials Au.