Doping is a powerful technique for engineering the electrical properties of organic semiconductors (OSCs), yet efficient n-doping of OSCs remains a central challenge. Herein, the discovery of two organic superbase dopants, namely P2-t-Bu and P4-t-Bu as ultra-efficient n-dopants for OSCs is reported. Typical n-type semiconductors such as N2200 and PC 61 BM are shown to experience a significant increase of conductivity upon doping by the two dopants. In particular, the optimized electrical conductivity of P2-t-Bu-doped PC 61 BM reaches a record-high value of 2.64 S cm −1 . The polaron generation efficiency of P2-t-Bu-doped in PC 61 BM is found to be over 35%, which is 2-3 times higher than that of benchmark n-dopant N-DMBI. In addition, a deprotonation-initiated, nucleophilic-attack-based n-doping mechanism is proposed for the organic superbases, which involves the deprotonation of OSC molecules, the nucleophilic attack of the resulting carbanions on the OSC's 𝝅-bonds, and the subsequent n-doping through single electron transfer process between the anionized and neutral OSCs. This work highlights organic superbases as promising n-dopants for OSCs and opens up opportunities to explore and develop highly efficient n-dopants.

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In this paper, the ethylene propylene diene monomer (EPDM) was used as a composite matrix and octadecylamine-functionalized graphene oxide (GA) was applied as insulation nanofiller to prevent plasticizer migration. To study the anti-migration behavior of EPDM under plasticizer environment and different temperatures, we investigated the diffusion of dioctyl phthalate (DOP) in EPDM and its composites. The migration kinetics of DOP into EPDM composites with respect to filler and temperature were observed by the immersion absorption method. The process is dynamic and conforms to Fick's law. The composite show a 90% increase in tensile strength and 151% improvement in elongation at break by the addition of 5 phr filler of GA. Meanwhile, the EPDM/GA composite show an obviously improved anti-migration performance, compared to pure EPDM at different temperatures, the composite show a 22.68%, 17.35%, 14.95%, 7.63% increase. Well layer-structure of graphene offers a chance to improve the anti-migration performance of insulation.

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