Molecular Doping Directed by a Neutral Radical

Molecular doping makes possible tunable electronic properties of organic semiconductors, yet a lack control the process narrows its scope for advancing electronics. Here, we demonstrate that molecular can be improved by introducing neutral radical molecule, namely nitroxyl (2,2,6,6-teramethylpiperidin-i-yl) oxyl (TEMPO). Fullerene derivatives are used as host and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazoles (DMBI-H) n-type dopant. TEMPO abstract hydrogen atom from DMBI-H transform latter into much stronger reducing agent DMBI•, which efficiently dopes fullerene derivative to yield an electrical conductivity 4.4 S cm–1. However, without TEMPO, is only weakly doped likely hydride transfer following inefficient electron transfer. This work unambiguously identifies pathway in derivative/DMBI-H systems presence accompanied In absence inevitably leads formation less symmetrical hydrogenated anions or radicals, adversely affect packing. By adding exclude such species and, thus, improve charge transport. addition, lower temperature sufficient meet efficient TEMPO. Thereby, provide extra process, enabling enhanced thermoelectric performance at low processing temperature.