High Efficiency n‐Type Doping of Organic Semiconductors by Cation Exchange

Achieving efficient doping in n‐type conjugated polymers is crucial for their application in electronic devices. In this study, an n‐type doping method is developed based on cation exchange that maintains a high doping level while ensuring a high degree of structural order, leading to significantly improved electrical conductivity. By investigating various dopants and ionic liquids, it is discovered that the choice of dopant influences doping efficiency, while the selection of ionic liquid affects cation exchange efficiency. Through careful selection of suitable dopants and ionic liquids, High doping levels are achieved remarkably in a short period, resulting in the highest conductivity (nearly 1 × 10−2 S cm−¹) compared to other doping methods for poly{[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)} (N2200). The findings highlight the robustness and efficiency of cation exchange doping as an effective approach for achieving high‐quality n‐type doping in conjugated polymers, thereby opening new avenues for the development of advanced polymer‐based electronic devices. This study demonstrates a high‐efficiency n‐type doping method for organic semiconductors through cation exchange, achieving high doping levels while preserving the material's structural integrity, thereby leading to high electrical conductivity. The method holds great potential for improving the performance of organic electronic devices, including thermoelectric and solar cells.