Electric Double Layer Gate Field-Effect Transistors Based on Si

Abstract

We demonstrate that polyurea films can be prepared by alternating deposition with automated deposition control involving quartz crystal microbalance monitoring and optical source heating. The thickness of the films was linearly controlled by changing the repetition time of deposition, and the stoichiometry obtained was much higher than + 5%.The surface roughness of a 600-nm-thick film was 0.5 nm, which ensures the nm thickness control of the deposited polymers. The piezoelectricity of the films was confirmed by directly measuring the current transient induced by mechanical stress and by measuring the capacitance change induced by electric field.

Electric-double-layer field-effect transistors with ionic liquids

“…Hasegawa et al tried to clarify the dynamic properties of a silicon-based EDL-FET. 111 Since the properties of silicon are well known, this FET is a good model to investigate the effects of ionic-liquid gate-dielectrics. They fabricated a top-gate, topcontact EDL-FET on a semi-insulating single-crystal Si wafer with an ionic-liquid EMIM-BF 4 as a gate-dielectric.…”

Ambipolar Carrier Injections Governed by Electrochemical Potentials of Ionic Liquids in Electric-Double-Layer Thin-Film Transistors of Lead- and Titanyl-Phthalocyanine

“…Recent progress in organic electronic devices, such as field-effect transistors, light-emitting diodes, and solar cells, is of considerable interest owing to the advantages of these devices with respect to flexibility, weight, and cost. − It also constitutes an advantage of organic compounds that the ease of chemical modification and the chemical variety enable a systematic screening to improve device performance. Ionic liquids have attracted great attention for future electronics because of their unique characteristics, such as low vapor pressure, chemical stability, wide electrochemical windows, and high capacitance. − For instance, the ionic liquids are useful as gate dielectrics for field-effect transistors; they form electric double layers (EDLs) on the surfaces of semiconductors with a thickness of ∼1 nm, and the EDL capacitances are higher than those of the conventional SiO 2 gate dielectrics. − In addition, they decrease the number of charge traps at solid/liquid interfaces, making the effective carrier concentration higher. To advance this promising route to flexible, high-performance organic devices, a better understanding of structure/property relationships of ionic liquids in EDL enhanced organic devices is clearly needed.…”

Solvent Effects on the Transient Characteristics of Liquid-Gate Field Effect Transistors with Silicon Substrate

“…To evaluate the tR of the EDL-FETs, the following experimental technique was used 17 . When a step-function gate bias was applied, the current increasing concentration, the time required to form the EDL becomes shorter, which leads to shorter tR.…”