Direct detection of molecular hydrogen upon p- and n- doping of organic semiconductors with complex oxidants or reductants

Molecular doping enables increasing the conductivity of organic semiconductors and plays an increasingly important role in emerging and established plastic electronics applications. 1,3-Dimethyl-2-(4-(dimethylamino)phenyl)-2,4-dihydro-1H-benzoimidazole (N-DMBI-H) and tris(pentafluorophenyl)borane (BCF) are established n- and p-dopants, respectively, but neither functions as a simple one-electron redox agent. Molecular hydrogen has been proposed to be a byproduct of several mechanisms for doping using both DMBI-H and BCF. In this paper we show for the first time the direct detection of molecular hydrogen in the uncatalyzed doping of a variety of polymeric and molecular semiconductors using these dopants. Our results provide insight in the doping mechanism, providing information complementary to that obtained from more commonly applied methods such as optical, electron spin resonance, and electrical measurements.