This is a horizontally mounted, double compartment photo-electrochemical H-Cell designed to measure characteristics of the electrolyte-gated (or solution-gated) transistors with photo-sensitive channel material, using liquid or gel electrolyte in stationary conditions. The sample can be irradiated vertically and horizontally. 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 screw mount in one compartment, while gate is mounted in a top casing of the second compartment. Compartments are separated with an ion-exchange membrane (e.g. DuPont’s Nafion® membrane), so the electrochemical products appearing at Gate and channel material do not affect the opposite electrode. A reference electrode can also be used 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 the chamber, using needle probes or toothless crocodile clips. The cell elements are constructed with materials that are inert to the sample (PEEK). 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.

Application note
This cell is designed mainly for light sensors and opto-logic gates based on following types of electrolyte-gated transistors with photo-sensitive channel material: 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). Various gate electrodes are suitable for this cell including metal wires and meshes as well as 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.

Select electrolyte type:
water-based electrolyte
organic electrolyte