Researchers introduce a novel ligand to improve the efficiency and durability of perovskite quantum dot solar cells, boosting efficiency to 15.3% by fixing surface distortions in quantum dots.
A team led by Professor Jongmin Choi from DGIST’s Department of Energy Science and Engineering, in collaboration with Professor Tae Kyung Lee from Gyeongsang National University and Professor Younghoon Kim from Kookmin University, has made significant advances. They’ve pioneered a new technique that enhances both performance and longevity of solar cells through the application of “perovskite quantum dots.” By tackling the distortions found on the surface of these quantum dots, they succeeded in creating more durable solar cells.
Perovskite quantum dots serve as essential materials for the upcoming generation of solar cells. Known for their remarkable abilities to convert light to electricity effectively and for being easy to manufacture on a large scale, these materials require that the “ligands” which bind to their surfaces be replaced for optimal use in solar cells. Unfortunately, this replacement often leads to distortions that can be compared to crumpled paper, negatively impacting both performance and lifespan of the solar cells.
To overcome this challenge, Professor Choi’s team implemented short ligands that grip the quantum dots tightly from both sides, essentially smoothing out the crumpled surfaces. This method aids in restoring the lattice structure and reducing surface defects, which allows the solar cells to function more efficiently while also increasing their durability. As a result, the power conversion efficiency of these solar cells rose from 13.6% to 15.3%, and they maintained 83% of their performance after 15 days, demonstrating remarkable stability.
“Our research focused on minimizing the defects on the quantum dots’ surfaces and enhancing their stability through the introduction of these amphiphilic ligands, allowing us to significantly boost efficiency and stability of the solar cells,” stated Professor Jongmin Choi from DGIST. “We aim to keep pursuing our research into stabilizing perovskite quantum dot surfaces, with hopes to apply our findings across different photoelectric technologies.”
This groundbreaking study was a collaboration among DGIST’s Professor Jongmin Choi, Gyeongsang National University’s Professor Tae Kyung Lee, and Kookmin University’s Professor Younghoon Kim, notably led by researchers Gayoung Seo and Sanghun Han from DGIST, along with Donggyu Lee, a Ph.D. candidate at Gyeongsang National University. The project received backing from the National Research Council of Science & Technology’s Creative Convergence Research Initiative, DGIST’s R&D Program, and the New Faculty Research Foundation Project at Gyeongsang National University. The findings were shared in the international journal Chemical Engineering Journal on September 15, 2024.