| AVS 66th International Symposium & Exhibition | |
| Thin Films Division | Thursday Sessions |
| Session TF-ThP |
| Session: | Thin Films Poster Session |
| Presenter: | Cheng Zhang, University of Tennessee Knoxville |
| Authors: | C. Zhang, University of Tennessee Knoxville W. Zhao, Huazhong University of Science and Technology, China S. Bi, Huazhong University of Science and Technology, China C.M. Rouleau, Oak Ridge National Laboratory J.D. Fowlkes, Oak Ridge National Laboratory W.L. Boldman, University of Tennessee Knoxville G. Gu, Brookhaven National Laboratory Q. Li, Brookhaven National Laboratory G. Feng, Huazhong University of Science and Technology P.D. Rack, University of Tennessee Knoxville |
| Correspondent: | Click to Email |
Ionic liquids (ILs) have been investigated extensively due to its unique ability to form the electric double layer (EDL) which induces high electrical field. For certain materials low temperature IL charging is needed to limit the electrochemical etching. Here we report our investigation of the low temperature charging dynamics in two widely used ILs – DEME-TF2N and C4mim-TF2N. Results show that the formation of the EDL at ~220 K requires several hours relative to milliseconds at room temperature, and an equivalent voltage Ve is introduced as a measure of the EDL formation during the biasing process. The experimental observation is supported by molecular dynamic simulation, which shows that the dynamics are logically a function of gate voltage, time and temperature. To demonstrate the importance of understanding the charging dynamics, a 140 nm thick FeSe0.5Te0.5 film was biased using the DEME IL, showing a tunable Tc between 18 and 35 K. Notably, this is the first observation of the tunability of the Tc in thick film FeSe0.5Te0.5 superconductors.