Extremely Electron‐Withdrawing Lewis‐Paired CN Groups for Organic p‐Dopants

P‐type chemical doping (p‐doping) is a key technique to modulate the optical, electrical, and electronic properties of organic semiconductors. However, typical functional groups in organic p‐dopants have insufficient electron‐withdrawing strength, and the inevitable diffusion of dopants in host matrices degrades doping stabilities. Herein, we utilize extremely electron‐withdrawing Lewis‐paired CN groups as a new class of building blocks for designing unprecedentedly strong organic p‐dopants with excellent doping stability. Various Lewis acids are paired with CN‐functionalized conjugated molecules in the solution state, which strengthens the electron‐withdrawing properties of CN groups almost twofold. The large dopants afford outstanding doping stability against continuous heating and long‐term atmospheric exposure, which is promising for practical applications in devices. Given the broad applicability of this simple combinatorial approach, it may impact many fields of (opto)electronics. The use of various CN‐functionalized conjugated molecules and Lewis acids has led to the synthesis of unprecedentedly strong organic p‐dopants (LUMO level down to −5.93 eV) exhibiting excellent doping stability (over 40 h at 120 °C). Lewis pairing leads to the electron‐withdrawing properties of the CN groups increasing almost twofold and the dopant size enlarging significantly.