Electrolyte-Gated Transistor Bottom Mount Cell - 15 mL, 0.2 cm2
This is a stationary solution electrochemical cell designed to measure characteristics of electrolyte-gated (or solution-gated) transistors using liquid or gel electrolyte. Measured transistor sample can be fabricated on a rigid or flexible flat substrate (not included in the setup) with conducting thin film source and drain, and a layer of conducting or semiconducting channel material. The sample is loaded from the bottom via magnetic or screw mount, while gate is mounted in a top casing. A reference electrode can also be mounted in the top casing in case it is needed to control the channel/electrolyte interfacial potential or perform an electrochemical pre-treatment on the channel material. Source and drain electrodes can be accessed through cut-outs in a cell bottom casing, using needle probes or toothless crocodile clips. The cell elements are constructed with materials that are inert to the sample (glass, PEEK and Fluorocarbons). It well fits aqueous (FKM/EPDM O-Rings) and organic solvent (FFKM O-Rings) electrolyte requirements. The construction is gas-tight and can be used when the removal and exclusion of contaminants such as oxygen and water is required by bubbling of an inert gas through the electrolyte. See the assembly demonstration here.
This cell is designed for following types of electrolyte-gated transistors: Electrolyte-Gated Field Effect Transistor (EG-FET), Electrolyte-Gated Organic Field Effect Transistor (EGOFET), Organic Electrochemical Transistor (OECT), Ion-Sensitive Field Effect Transistor (ISFET) and Ion-sensitive Organic Field Effect Transistor (ISOFET). This system can be also used to measure characteristics of transistors with mono-layer graphene as a channel conductor. In this case O-Ring conveniently limits the area of interaction with an electrolyte and the edges of graphene do not create a background signal.
The reference electrode tip should be placed close to the bottom of the chamber (3-5 mm), where the working electrode is exposed to the electrolyte. This will ensure a negligible potential drop throughout the electrolyte solution for low-current experiment. Various gate electrodes are suitable for this cell including metal wires and graphite rod, which can further be functionalized with ion-selective membrane, if needed. The bubbling of gas through the solution must be stopped prior to experiment.
nominal exposure area: 0.2 cm2 (O-Ring OD: 5mm, CS: 1mm; other values available on request)
minimum electrolyte volume: 3 mL
maximum electrolyte volume: 15 mL
electrode plug diameter: 6 mm
minimum substrate size: 10 mm x 10 mm
1 x lid
1 x glass chamber
1 x bottom casing
1 x sample mount
1 x plug
Examples of source, drain and channel layouts for mask/screen/pattern design available on request ( .pdf, .svg, .ai, etc… )