POS5-0838
Core-Linked Star-Shaped Trimer Design Enables Highly Stretchable and Efficient Organic Solar Cells
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
Kihyun Bae (KAIST)
Co-Author(s)
Abstract
Organic solar cells (OSCs) have recently achieved unprecedented power conversion efficiencies (PCEs), achieving the remarkable 20% milestone. This has been driven primarily by the rapid development of small molecule acceptors (SMAs). However, SMA-based OSCs are severely hindered by their inherent lack of long-term stability and mechanical fragility. In this study, we synthesized the core-linked star-shaped trimer (TCB-C) from the small molecule acceptor monomer (CB-Cl). This strategy increased the glass transition temperature (Tg) that thermodynamically locks the active layer morphology against thermal stress. At the same time, the core-linked star-shaped geometry of the trimer increased the amorphous domains of the active layer, leading to enhanced mechanical properties compared with the monomer-based system. When TCB-C is incorporated as a guest component to the PM6:Y6-16 ternary system, the increased molecular weight of the trimeric structure raises the glass transition temperature (Tg), giving the ternary devices exceptional thermal stability (T80 = 1,855 hours) compared to the PM6:Y6-16 system (T80 = 240 hours). Intrinsically stretchable organic solar cells (IS-OSCs) fabricated with the PM6:Y6-160.6:TCB-C0.6 device retained 80% of their initial power conversion efficiency under 28% applied mechanical strain (PCE80% = 28%), significantly outperforming the control PM6:Y6-16 devices (PCE80% = 14%). These findings suggest that core-linked star-shaped trimers have the potential to serve as a promising material for the development of high-performance organic solar cells.
