Low‐Cost Nucleophilic Organic Bases as n‐Dopants for Organic Field‐Effect Transistors and Thermoelectric Devices
Huan Wei, Pingan Chen, Jing Guo, Yu Liu, Xincan Qiu, Huajie Chen, Zebing Zeng, Thuc‐Quyen Nguyen, Yuanyuan Hu
Abstract
Abstract Doping is a powerful technique for tuning the electrical properties of organic semiconductors (OSCs). Although numerous studies are performed on OSC doping, thus far only a few n‐type dopants have been developed. Herein, two low‐cost nucleophilic organic bases are reported, namely 1,5,7‐Triazabicyclo [4.4.0] dec‐5‐ene (TBD) and 1,5‐Diazabicyclo [4.3.0] non‐5‐ene (DBN) for n‐doping of OSCs. The two dopants are found to significantly enhance the electrical conductivity of OSCs. In particular, compared to the classic n‐dopant 4‐(2,3‐Dihydro‐1,3‐dimethyl‐1 H ‐benzimidazol‐2‐yl)‐ N , N ‐dimethylbenzylamine ( N ‐DMBI), DBN results in significantly higher conductivity and also lower activation energy in N2200 films, indicating its high doping performance. The utilization of the n‐dopants for improving device performance and controlling the device polarity of organic field‐effect transistors are demonstrated. Furthermore, these dopants are employed for fabricating organic thermoelectric devices, and the power factor value of DBN‐doped N2200 films is found to be about 1.6 times higher than that of N ‐DMBI‐doped films. These results show the feasibility of using low‐cost organic bases as efficient n‐dopants and demonstrate their promising applications in organic electronics.