This report is concerned with the study of electrolyte gated thin film transistors (FET). Recently electrolyte gating become a popular technique in studying carrier density dependent physical properties in solid state materials, due to its capability of producing large carrier density modulation. In this project we tried to achieve high charge carrier density in ionic liquid-gated field effect transistor and resistance tuning in gold thin films.

Here we used silicon as semiconductor substrate upon which hall bar structured gold thin film was deposited, one of the hall bar branch was isolated from the hall bar structure and gated using DEME TFSI electrolyte. For this sample we studied its transfer, output characteristics and electric double layer charging and discharging. Later on for resistance tuning part we used sapphire wafer as substrate, for which we used a different mask where gate is already isolated from channel. Electrical insulation of sapphire insures that no contribution in the tuning due to substrate. The core of this report is devoted to a better understanding of the mechanism of electrolytic-gating on thin FETs and its applications. 

This report contains the measurements performed at room temperature and low temperature. This report enlightens the various steps of fabrication of thin film transistors, measurement performed on the samples and instrumentation.