Electrolyte versus Dielectric Gating of Two-Dimensional Materials

Electrolyte gating has several advantages over the more conventional dielectric gating. The most important is the ability to induce large charge carrier densities with a fraction of the voltage required by a typical dielectric gate. For this reason, electrolyte gating has become a popular choice for scientists working on 2D materials research, where efficient and controllable charge doping by electrostatic gating is a highly desirable alternative to the conventional substituent doping implemented in bulk materials. In this Perspective, we compare electrolyte gating with dielectric gating and evaluate the strengths and weaknesses of both approaches. We highlight the recent progress in electrolyte gating and the scientific discoveries that it has helped achieve and outline the current and future trends in gating of 2D materials, including dual gating, electrochemically controlled optoelectronics, and electric field-effect-driven catalysis.