n-doping of organic semiconductors catalysed by organometallic complexes

Molecular doping is essential for optimizing carrier concentration, charge mobility, and energy levels of organic semiconductors (OSCs), thereby enhancing device performance. However, efficient n(electron)-type doping remains challenging, as conventional techniques often fail to achieve high doping efficiency with minimal counterion-induced disorder under mild conditions. Here, we present a catalysed n-doping strategy for OSCs using air-stable, cost-effective, and commercially available soluble organometallic complexes, such as Pt(COD)Cl2, which enable rapid n-dopant activation with just 10 s of annealing at 120 oC. This approach demonstrates excellent generality across diverse OSCs, dopants and catalysts, achieving electrical conductivities exceeding 230 S cm-1 with up to 10-fold improvements over existing catalyst-assisted n-doping methods. Importantly, it mitigates counterion-induced structural disorder in doped OSCs, leading to a high power factor of 175 µW m-1 K-2 and thermoelectric figure of merit (ZT) of 0.43 at room temperature for catalytically N-DMBI-doped polymer films. This strategy addresses long-standing challenges in n-doping while unlocking new avenues for next-generation organic electronics.