Semiconductor Device-Based Sensors for Gas, Chemical, and Biomedical Applications

ZnO Thin-Film and Nanowire-Based Sensor Applications 199

© 2011 by Taylor & Francis Group, LLC

3% O

3

in O

2

. The changes in current are much larger than for the case of hydrogen detection. Over a

relatively limited range of O

3

partial pressures in the N

2

ambient, the conductance increased accord-

ing to G = (G

O

+ A(P

O3

)

0.5

)

−1

, where A is a constant and G

O

the resistance in a pure N

2

ambient. This is

a similar dependence to the case of CO detection by SnO

2

conduction sensors, in which the effective

conductance increases as the square root of CO partial pressure. The gas sensitivity can be calculated

from the difference in conductance in O

3

-contain ...