LAUSR

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, we report the discovery of two organic superbase dopants, namely P2-t-Bu and P4-t-Bu as ultra-efficient n-dopants for OSCs. Typical n-type semiconductors such as N2200 and PC61 BM are shown to experience significant increase of conductivity upon doping by the two dopants. In particular, the optimized electrical conductivity of P2-t-Bu-doped PC61 BM reaches a record-high value of 2.64 S/cm. The polaron generation efficiency of P2-t-Bu-doped in PC61 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. Our work highlights organic superbases as promising n-dopants for OSCs and opens up opportunities to explore and develop highly efficient n-dopants. This article is protected by copyright. All rights reserved.