Patent ID: 11867657
Assignee: KING ABDULLAH UNIVERSITY OF SCIENCE AND TECHNOLOGY
Field: Measurement (Instruments)
Classification: CPC G  Y | IPC G

Claim 4:
5. A gas detection system for determining a concentration of a gas, the system comprising:
a first transistor having an indium (In) gallium (Ga) zinc (Zn) oxide (O) (IGZO) thin-film formed over a dielectric layer, wherein the IGZO thin-film interacts with the gas and changes a sensing current through the first transistor;
a second transistor (T1) electrically connected to the first transistor to form a master branch, wherein the second transistor (T1) has an identical structure as the first transistor, and a corresponding IGZO thin-film is encapsulated with a material to prevent an interaction between the IGZO thin-film of the second transistor (T1) and the gas, while the IGZO thin-film of the first transistor is free to directly interact with the gas;
third and fourth transistors (T2, T3) electrically connected to each other and forming a secondary branch, wherein the third and fourth transistors (T2, T3) are identical to the second transistor (T1); and
an inverter electrically connected to the third and fourth transistors (T2, T3),
wherein the inverter receives a voltage due to (1) a reference current from the third transistor (T2), and (2) a current from the fourth transistor (T3), which is identical to the sensing current of the first transistor, and outputs a digital value indicative of the concentration of the gas.