Details

Autor(en) / Beteiligte

• Wang, Zhen
• Guo, Yu
• Liu, Xianzhao
• Shu, Wenchao
• Han, Guangchao
• Ding, Kan
• Mukherjee, Subhrangsu
• Zhang, Nan
• Yip, Hin-Lap
• Yi, Yuanping
• Ade, Harald
• Chow, Philip C Y

Titel

The role of interfacial donor-acceptor percolation in efficient and stable all-polymer solar cells

Ist Teil von

• Nature communications, 2024-02, Vol.15 (1), p.1212-1212, Article 1212

Ort / Verlag

England: Nature Publishing Group

Erscheinungsjahr

2024

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Polymerization of Y6-type acceptor molecules leads to bulk-heterojunction organic solar cells with both high power-conversion efficiency and device stability, but the underlying mechanism remains unclear. Here we show that the exciton recombination dynamics of polymerized Y6-type acceptors (Y6-PAs) strongly depends on the degree of aggregation. While the fast exciton recombination rate in aggregated Y6-PA competes with electron-hole separation at the donor-acceptor (D-A) interface, the much-suppressed exciton recombination rate in dispersed Y6-PA is sufficient to allow efficient free charge generation. Indeed, our experimental results and theoretical simulations reveal that Y6-PAs have larger miscibility with the donor polymer than Y6-type small molecular acceptors, leading to D-A percolation that effectively prevents the formation of Y6-PA aggregates at the interface. Besides enabling high charge generation efficiency, the interfacial D-A percolation also improves the thermodynamic stability of the blend morphology, as evident by the reduced device "burn-in" loss upon solar illumination.