Potentiometry in Gas Phase
When a dry, solid state OS is exposed to a gas or a vapor that can donate or accept electrons, a charge transfer complex is formed between the OS and the gas. Such interaction is called secondary doping, which results in modulation of work function (WF) of the OS. Such interaction can be measured with a Kelvin Probe or with a field-effect transistor. From the sensing point of view the biggest difference and advantage of WF-FET vis-à-vis ion sensors is the fact that no external reference electrode is needed because silicon is used as reference and its WF is stable under normal operating conditions. That fact alone makes the WF-FETs ideally suited for miniaturization, leading to gas-sensing arrays3.
- Jiri Janata and Mira Josowicz, J.Solid State Electrochem. 13 (2009) 41-49, “Organic Semiconductors in Potentiometric Gas Sensors”
- Jiri Janata, Principles of Chemical Sensors, 2nd Edition, Springer, 2009, New York
- Jiri Janata, Coll.Czechoslov..Chem.Commun. 2009, 74, 1623–1634, Potentiometry in gas phase