Self-Organization of Ions at the Interface between Graphene and Ionic Liquid DEME-TFSI
By Hu, Guangliang; Pandey, Gaind P.; Liu, Qingfeng; Anaredy, Radhika S.; Ma, Chunrui; Liu, Ming; Li, Jun; Shaw, Scott K.; Wu, Judy
Published in ACS Applied Materials & Interfaces
Abstract
Electrochemical effects manifest as nonlinear responses to an applied electric field in electrochemical devices, and are linked intimately to the molecular orientation of ions in the electric double layer (EDL). Herein, we probe the origin of the electrochemical effect using a double-gate graphene field effect transistor (GFET) of ionic liquid N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium bis(trifluoromethylsulfonyl)imide (DEME-TFSI) top-gate, paired with a ferroelectric Pb0.92La0.08Zr0.52Ti0.48O3 (PLZT) back-gate of compatible gating efficiency. The orientation of the interfacial molecular ions can be extracted by measuring the GFET Dirac point shift, and their dynamic response to ultraviolet