The transport properties of an efficient n-type dopant of Li₂CO₃ into the organic semiconductor Bepp₂ by using admittance spectroscopy measurements. The electron mobility (∼10⁻⁴ cm² V⁻¹ s⁻¹) of the doping film is two orders of magnitude higher than that of pure Bepp₂ film.

The investigation on doping mechanism demonstrates that there occurs electron transfer from Li₂CO₃ to Bepp₂, which reduces the electron injection barrier and significantly enhances the electron mobility.