An Amidine-Type n-Dopant for Solution-Processed Field-Effect Transistors and Perovskite Solar Cells

5 years ago

An Amidine-Type n-Dopant for Solution-Processed Field-Effect Transistors and Perovskite Solar Cells

Yuanping Yi, Yinhua Zhou, Jiashun Duan, Tiefeng Liu, Xike Gao, Youyu Jiang, Congwu Ge, Fei Qin, Lin Hu, Fangyuan Jiang, Bin Hu, Xiaoyi Ma, Sixing Xiong

This study reports an effective amidine-type n-dopant of 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) that can universally dope electron acceptors, including PC61BM, N2200, and ITIC, by mixing the dopant with the acceptors in organic solvents or exposing the acceptor films in the dopant vapor. The doping mechanism is due to its strong electron-donating property that is also confirmed via the chemical reduction of PEDOT:PSS (yielding color change). The DBU doping considerably increases the electrical conductivity and shifts the Fermi levels up of the PC61BM films. When the DBU-doped PC61BM is used as an electron-transporting layer in perovskite solar cells, the n-doping removes the “S-shape” of J–V characteristics, which leads to the fill factor enhancement from 0.54 to 0.76. Furthermore, the DBU doping can effectively lower the threshold voltage and enhance the electron mobility of PC61BM-based n-channel field-effect transistors. These results show that the DBU can be a promising n-dopant for solution-processed electronics. An effective solution-processed amidine-type n-dopant of 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU), which can universally dope electron acceptor materials, including PC61BM, N2200, and ITIC, is reported. The DBU doping can enhance the performance of the perovskite solar cells and the electron mobility of the field-effect transistors.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adfm.201703254