March 8, 2024 marks International Women’s Day under the theme “Invest in women: Accelerate progress.” Climate Positive Energy is pleased to recognize and support women in science, technology, engineering, and math (STEM) year-round through our multidisciplinary research program, which includes opportunities for training and career development. On International Women’s Day, we are pleased to delve into the research journey of Nina-Francesca Farac, whose green chemistry research is helping to expand the field of solar cell technology.
In 2022, Nina was one of 13 University of Toronto graduate students to receive $15,000 from Climate Positive Energy to further sustainability-related research. Titled “Harnessing More Solar Energy with Green Chemistry: The Sustainable Design of Hybrid Organic Materials for Next-Generation Organic Solar Cells,” Nina’s project focused on the development of new organic molecules with electron-conducting properties for applications in organic solar cells and in energy-efficient diodes, or devices that convert electricity into light. Now completing the final year of her PhD, Nina is working in The Bender Laboratory to advance her research.
With a bachelor’s in chemistry, Nina’s background is in science. She collaborates with a multidisciplinary team led by Chemical Engineering Professor and CPE member Timothy Bender.
“After studying chemistry as a pure science in undergrad, I found myself gravitating towards the application side [of chemistry],” she explains. “What interested me about Professor Bender’s lab is that the chemist’s principal role is to create compounds that are then given to device engineers, to then evaluate their efficiency in organic electronics. I wanted to find a path that tied together chemistry, sustainability, and impact.”
Nina’s impact is in the field of sustainability and green chemistry. Her research focuses on synthesizing low embodied energy small molecules, which take less energy to produce and have a smaller carbon footprint than other molecules.
Solar cells are devices that convert sunlight directly into electricity. The main differences between organic and inorganic solar cells lie in the materials used, flexibility, cost, and efficiency in converting energy. While researchers are continually working on improving both types of solar cells for a brighter and more sustainable future, Nina focuses on the organic counterparts and their various merits – including that they are lightweight, inexpensive, flexible, and have increased sustainability in the production process.
“We take these low embodied energy molecules, and we apply them into organic solar cells to see how well they perform.”
Based on performance metrics obtained by the research team, Nina and her team can then tailor the compounds in different ways on the chemical scale to obtain properties that make the devices better for different applications.
“My small molecules not only have the small embodied energy aspect, they also have a uniquely broad absorption. When we think about an organic solar cell, we try to harvest as much of the sun’s energy as possible to then convert it into usable electricity. If you now have a compound that takes less energy to make, and absorbs a lot more energy, you have a two-for-one beneficial compound.”
Nina recently collaborated with other U of T researchers in the Bender Lab to submit a revised manuscript of a paper that speaks to the life cycle assessments of this technology. “We found that the solvent used to make our compounds had the highest embodied energy that goes into the synthetic process. In light of that life cycle assessment, we found an alternative solvent and cut down the solvent embodied energy significantly.” The researchers demonstrated that with the solvent swap, they could create the exact same molecule – the main difference being that the synthetic process had an overall lower embodied energy. “It’s just as functional, but now we’ve actually decreased how much energy goes into making it, even though the energy required was already quite low to begin with.”
Nina speaks to another exciting research finding related to her CPE-funded project: “I made around 6 new materials, and two of them show promising behaviour as dopant light harvesters. They complement the light absorption of another compound, helping to improve the overall efficiency of solar cells.”
Now focusing on completing her PhD, Nina says her priority is to help her research make new ground for future students from all areas of study who want to join the Bender Lab.
“If you look at any major breakthrough in science, their impact didn’t exclusively emanate from just one group from one university or from one institution. It’s a cumulative effect of different groups. I hope that my research adds to a cumulative effect showing that organic solar cells have a place in the renewable energy space.”
To learn more about Nina’s project, visit: https://cpe.utoronto.ca/project/the-sustainable-design-of-hybrid-organic-materials-for-next-generation-organic-solar-cells/
Connect with Nina on LinkedIn: https://www.linkedin.com/in/ninafarac-phdc