Thermally Activated n‐Doping of Organic Semiconductors Achieved by N‐Heterocyclic Carbene Based Dopant

Abstract Molecular doping plays an important role in the modification of carrier density of organic semiconductors thus enhancing their optoelectronic performance. However, efficient n‐doping remains challenging, especially owing to the lack of strongly reducing and air‐stable n‐dopants. Herein, an N‐heterocyclic carbene (NHC) precursor, DMImC, is developed as a thermally activated n‐dopant with the excellent stability in air. Its thermolysis in situ regenerates free NHC and subsequently dopes typical organic semiconductors. In sequentially doped FBDPPV films, DMImC does not disturb the π–π packing of the polymer and achieves good miscibility with the polymer. As a result, a high electrical conductivity of up to 8.4 S cm −1 is obtained. Additionally, the thermally activated doping and the excellent air stability permit DMImC to be noninteractively co‐processed with polymers in air. Our results reveal that DMImC can be served as an efficient n‐dopant suitable for various organic semiconductors.