Two star-shaped helical perylene diimide (PDI) electron acceptors TPDI2 and FTPDI2 were designed and synthesized for nonfullerene organic solar cells (OSCs). The integration of helical PDIs into a three-dimensional structure provides a new strategy to tune the intermolecular interactions, and the as-cast blend films with PTB7-Th show favorable morphology as well as efficient charge transfer and separation, as evidenced by the morphology and femtosecond transient absorption (fs-TA) spectroscopy studies. A trade-off between suppressing the self-aggregation and maintaining the charge-transfer properties was achieved by FTPDI2. Using PTB7-Th as the electron donor, the FTPDI2-based nonfullerene OSCs show a high power conversion efficiency of 8.28%, without the assistance of any additives.

An n-type helical molecule perylene diimide (PDI2) has been explored as an efficient interfacial layer between TiO2 and perovskite, which can restrain the light-soaking instability and reduce hysteresis in perovskite solar cells. A champion device PCE of 19.84% has been achieved after incorporating the PDI2 interlayer.

Organic redox-active molecules have been identified as promising cathodes for practical usage of potassium-ion batteries (PIBs) but still struggle with serious dissolution problems and sluggish kinetic properties. Herein, we propose a pseudocapacitance-dominated novel insoluble carbonyl-based cathode, [2,6-di­[1-(perylene-3,4,9,10-tetracarboxydiimide)]­anthraquinone, AQ–diPTCDI], which possesses high reversible capacities of 150 mAh g–1, excellent cycle stability with capacity retention of 88% over 2000 cycles, and fast kinetic properties. The strong intermolecular interactions of AQ–diPTCDI and in situ formed cathode electrolyte interphase films support it against the dissolution problem. The high capacitive-like contribution in capacities and fast potassium-ion diffusion enhance its reaction kinetics. Moreover, a symmetric organic potassium-ion battery (OPIB) based on AQ–diPTCDI electrodes also exhibits outstanding K-storage capability. These results suggest that AQ–diPTCDI is a promising organic cathode for OPIBs and provide a practicable route to realize high-performance K storage.

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