Importance of structural hinderance in performance–stability equilibrium of organic photovoltaics

Fan, B., Gao, W., Wu, X. et al.

Nature Communications 13, 5946 (2022).

doi.org/10.1038/s41467-022-33754-3

Power conversion efficiency and long-term stability are two critical metrics for evaluating the commercial potential of organic photovoltaics.

Although the field has witnessed a rapid progress of efficiency towards 19%, the intrinsic trade-off between efficiency and stability is still a challenging issue for bulk-heterojunction cells due to the very delicate crystallization dynamics of organic species. Herein, the research team from the City University of Hon Kong developed a class of non-fullerene acceptors with varied side groups as an alternative to aliphatic chains.

Delay-time charge extraction by linearly increasing voltage (CELIV) was measured on the all-in-one platform of Paios (FluximAG). A light pulse with duration of 50 μs generated from an 810 nm LED lamp (light intensity 100%) was applied prior to a voltage ramp of 1 V μs–1.

The delay time between light pulse and voltage ramp was varied from 0.2 to 10 μs. During the delay time, the open circuit was kept by applying the transient photovoltage signal to ensure no current is flowing.