Enhancing organic solar cells' green glow

• Organic solar cells could be made even greener by switching over the solvents utilized in their manufacture. Today's toxic chlorinated solvents can be changed by plant-derived options without influencing the resulting solar cells' light-capturing efficiency, KAUST researchers have actually revealed.

Organic photovoltaics (OPVs) are just one of the greenest solar cell technologies, contributing just three grams of CO2 equivalent carbon emissions per KW of energy. "Nevertheless, their manufacture still relies upon halogenated solvents that, in addition to being linked to reproductive risks and cancer, are stemmed from petrochemical procedures," says Daniel Corzo, a Ph.D. pupil in Derya Baran's laboratory, that led the job.

" We wished to locate green choices to protect the health and wellness of workers when these cells are manufactured at a larger range and also to further reduce the carbon impact of OPVs."

Solvents are important to OPV manufacture as they are the basis of the printable inks that organic solar cells are made from. "These inks require the organic energetic materials to continue to be in solution throughout handling and afterwards take shape under optimized conditions as the ink dries," Corzo says. "Solvent option considerably affects OPV processing and also general device efficiency."

The team identified possible alternative solvents by applying a framework called the Hansen solubility formula. "This approach gauges exactly how similar particles are to each other based on their molecular communications," Corzo clarifies. "You can select solvents that are alike at the molecular degree however have helpful residential or commercial properties, including reduced poisoning, or that originate from renewable sources."

The method disclosed that plant-based solvents called terpenes-- a group that includes the aromatic oils eucalyptol and also limonene-- could be appropriate substitutes. "These solvents can be derived from plant deposit, such as eucalyptus leaves or orange peel, or be generated from algae as well as bacteria in bioreactors," Corzo says.

Solvent blends based upon these substances verified to be an exceptional fit for OPV manufacture. "We acquired solar cells with efficiencies above 16% using terpene-based inks-- basically the like from chlorinated solvents-- but with an 85% reduced carbon impact and also with the possible to end up being carbon adverse in the future," Corzo says.

"Our company believe that numerous industries as well as tech programmers will benefit from terpene solvent development," Baran includes. The team has made their searchings for freely offered in an interactive online collection for green solvent option. "This collection can exceed using green solvents for organic electronic devices due to the fact that terpenes are likewise used in food and fragrance markets, as an example," she keeps in mind.

The findings are published in the journal Nature Energy.