Research Paper: Switching From Acceptor to FRET Donor: How the Organic Solar Cell Architecture Can Change the Role of a Chromophore
Scientific Summary
This study investigates the non-fullerene acceptor (NFA) o-IDT-BT-DCV in binary and ternary organic solar cells (OSCs) with a PM6:Y6 host blend. The core goal was to understand its role in enhancing performance and stability. While o-IDT-BT-DCV functions as an acceptor in binary PM6:o-IDT-BT-DCV devices (achieving 10.8% PCE), in ternary blends, it remarkably switches its role to an exciton donor. This enables sub-picosecond energy transfer to Y6, significantly boosting charge carrier generation and achieving a maximum power conversion efficiency (PCE) of 16.2%. Performance was further optimised with a 1,4-DITFB additive and higher molecular weight PM6, improving efficiency and film ordering.
Why it matters
This research is pivotal for advanced OSC design, revealing a novel charge generation pathway where a component acts as an exciton donor, improving light harvesting and photocurrent. The 16.2% PCE underscores its high-performance potential. Crucially, ternary devices demonstrated superior photostability, maintaining ≈80% efficiency over 1200 hours under 1-sun illumination, versus 40% for binary cells. This enhanced durability, linked to better-preserved crystalline order, addresses a critical barrier for OSC commercialisation, offering a pathway to more reliable and efficient solar energy solutions.
Publication Details
Jin, H., Mallo, N., Zhang, G., Lindsay, O., Chu, R., Gao, M., McAnally, S., Etchells, I.M., Burn, P.L., Gentle, I.R. and Shaw, P.E. (2025), Switching From Acceptor to FRET Donor: How the Organic Solar Cell Architecture Can Change the Role of a Chromophore. Adv. Funct. Mater., DOI: 10.1002/adfm.202420416.
Fluxim Tools Used
Fluxim’s LITOS LITE setup was explicitly used for photostability measurements. This instrument allowed for reliable, continuous 1-sun illumination and maximum power point (MPP) tracking in ambient air, providing essential long-term performance data crucial for evaluating the commercial viability and real-world durability of the developed solar cells.