Degradation-assisted doping of organic semiconductors enabled by Lewis acids.

The chemical doping of organic semiconductors with molecular dopants is crucial for high-performance organic electronic devices. Chemically stable dopants are commonly used, enabling electron transfer until a thermodynamic equilibrium is reached, which then terminates the doping process. Here we demonstrate that using p-dopants that chemically degrade after electron transfer via their radical anion can increase the hole densities in the semiconductor host by up to two orders of magnitude. In this degradation-assisted doping mechanism, the electron affinity of the doping agent only enables a limited amount of charge transfer. Subsequent dopant degradation effectively removes its products from co-defining the thermodynamic equilibrium and, thus, allows the doping reaction to persist. We demonstrate that the prototypical Lewis acid tris(pentafluorophenyl)borane (B(C6F5)3) exemplifies degradation-assisted doping, and provide the theoretical framework for this doping strategy offering new avenues for optimizing charge carrier densities in organic semiconductors.