Researchers fromKorea's Pohang University of Science and Technology (POSTECH), Ajou University, Daegu Gyeongbuk Institute of Science and Technology (DGIST) and Kookmin University have designed new polymeric hole transport materials that constitute a crucial element in perovskite quantum dot solar cells, leading to significant increase in their efficiency.
The team's hole transport materials include polymers based on sulfur and selenium compounds. These polymers exhibit structural features, such as planarization and locking of intermolecular arrangements, which increase charge mobility. Furthermore, asymmetric alkyl substituents of the polymers facilitate molecular interactions, thereby complementing the electrical properties of cells.
The newly designed polymers were evaluated through tests using a control group. The results indicate that solar cells that use hole transport materials containing selenium compounds achieved 15.2% of power conversion efficiency (PCE), maintaining 80% of their initial PCE even after 40 days. The findings of this research demonstrate that the newly designed hole transport materials can effectively increase charge mobility without the use of dopants, resulting in the highest PCE and increased stability in dopant-free perovskite quantum dot solar cells.
Professor Taiho Park, who led the research, explained: “The research findings represent a paradigm shift from conventional charge transport materials and are expected to be used in future research on solar cell devices.”