Highly Sensitive Oxygen Sensing Characteristics Observed in IGZO Based Gasistor in a Mixed Gas Ambient at Room Temperature

Oxygen (O2) sensing in trace amounts and mixed
gas is
essential in many types of industries. Semiconductor sensors have
proven to be invaluable tools for the O2 measurements in
a wide concentration range, but the sensors are only able to quantify
O2 in a concentration range of subppm, thus far, especially
in mixed gas. We present in this paper a new concept for O2 sensing with incomparable sensitivity using IGZO-films with oxygen
vacancy-based conducting filaments (CFs). O2 sensing relies
on rupturing of the CFs, and the proposed device quickly recovers
to the initial state using a pulse of 0.6 V/90 μs after the
sensing. The proposed device has a high sensitivity of 14 even at
an O2 concentration of 500 ppb, a detection limit of 150
ppb for O2 at RT, and excellent selectivity for O2 in mixed gas, which is remarkable compared to other gas sensors.
The proposed device can be widely used in gas sensors especially for
detecting O2 at a low ppb level, which is due to excellent
sensing characteristics.