Manipulating the Electronic Properties of 2D Materials with Ionic Liquids Seminar

Abstract:

Transition metal dichalcogenides (TMD), which consist of a transition metal (M), a chalcogen (X) and have the formula MX2, have shown to have a whole array of interesting electronic properties including semiconducting, metallic and superconductivity. Manipulation of these properties has taken many forms including chemical surface functionalisation, intercalation of molecules in between layers and electric field doping. The latter of these techniques allows precise control of the electronic state of the 2D material meaning a semiconducting insulating 2D material can be doped into the conducting state.

An ionic liquid field effect transistor is one example of electric field doping and one which is growing in popularity to tune the electronic properties of 2D materials. An ionic liquid is placed on top of the 2D material and a voltage is applied to an electrode in the liquid so as to induce charge separation within the liquid. The compact electrical double layer formed at the interface between the liquid and the 2D material induces a high level of doping and in this talk I will discuss the electrochemical effects of using ionic liquids as a gate dielectric as well as the novel electronic states which are induced in the 2D material.