Giant dimeric donors for all-giant-oligomer organic solar cells with efficiency over 16% and superior photostability

Increasing the molecular weight while maintaining mono-dispersity has been proved crucial in innovating high-performance photovoltaic materials in giant oligomeric acceptors. However, developing efficient giant oligomeric donors to replace the batch-varied polymers remains challenging due to a lack of design principles. Here, by designing two unique isomeric rhodanine-based linkers, we successfully regulate the assembly behaviors of giant dimeric donors (G-Dimer-Ds) and fabricate the first all-giant-oligomer OSCs pairing with giant dimeric acceptor DY. Multiple characterizations demonstrate the small homo-molecular interaction with strong thermal-driven assembly capability in G-Dimer-D2 simultaneously facilitates reducing energetic disorder, improving charge transport and obtaining stable morphology, resulting in a satisfactory efficiency of 15.70% and long-term photostability with an extrapolated T80 of ca.10,000 hours, and further enhancing thermal-driven assembly promotes efficiency of 16.05%. Our results provide construction approaches on efficient giant donors, and propose a promising type of OSC with completely definite structures, high efficiency and superior stability.

Caixuan Wang, Xiaoming Ma, Dan Deng, Hao Zhang, Rui Sun, Jianqi Zhang, Lili Zhang, Mengying Wu, Jie Min, Zhi-Guo Zhang, Zhixiang Wei