Novel method restores QD solar cells
Scientists from the DGIST, Gyeongsang National University and Kookmin University in Korea have developed a new method to improve both the performance and the stability of solar cells using perovskite quantum dots.
They developed longer-lasting solar cells by addressing the issue of distortions on the surface of quantum dots, which deteriorate the performance of solar cells.
Perovskite quantum dots have excellent light-to-electricity conversion capabilities and are easy to mass-produce. However, to use them in solar cells, the ligands attached to the quantum dot surface must be replaced. This process often leads to distortions of the quantum dot surface, resembling crumpled paper, which results in decreased performance and shorter lifespans for the solar cells.
To address this issue, the researchers used short ligands that securely hold the quantum dots from both sides, effectively uncrumpling the distorted surface.
The ligands help restore the distorted lattice structure, smoothing the crumpled surface of the quantum dots. This significantly reduces surface defects, enabling the solar cells to operate more efficiently and extending their lifespan. Consequently, the power conversion efficiency of the solar cells increased from 13.6 percent to 15.3 percent, demonstrating stability by maintaining 83 percent of their performance for 15 days.
“Through this research, we could minimize surface defects on the quantum dots and stabilize their surfaces by newly adopting these amphiphilic ligands, thereby significantly improving the efficiency and stability of the solar cells,” said Jongmin Choi from the Department of Energy Science and Engineering at DGIST. “We plan to continue our research on stabilizing the surface of perovskite quantum dots, hopefully applying the results to various photoelectric devices.”
This study was a joint effort by the research teams of DGIST's Jongmin Choi, Gyeongsang National University's Tae Kyung Lee, and Kookmin University's Younghoon Kim.
The study was supported by the National Research Council of Science & Technology’s Creative Convergence Research Project, the DGIST R&D Program, and the New Faculty Research Foundation Project at Gyeongsang National University. The research findings were published in the international journal Chemical Engineering Journal on September 15, 2024.
The research 'Multifaceted anchoring ligands for uniform orientation and enhanced cubic-phase stability of perovskite quantum dots' was published in Chemical Engineering Journal on September 15, 2024.
