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

Abstract

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.

Coordination of Tetracyanoquinodimethane-Derivatives with Tris(pentafluorophenyl)borane Provides Stronger p-Dopants with Enhanced Stability

“…We point out that the dopant solution changed color after one week of storage inside the glovebox, in agreement with a recent report on F4TCNQ-4(BCF), which was published during the revision of our present contribution, where the presence of water resulted in the formation of BCF complexes that prevent the formation of Lewis-paired p-dopants. 53…”