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

ZnO Thin-Film and Nanowire-Based Sensor Applications 209

© 2011 by Taylor & Francis Group, LLC

hydrogen from the ambient. Bulk ZnO Schottky diodes appear well suited to detection

of CO and C

2

H

4

. They are sensitive at temperatures as low as 90°C for percentage levels

of CO in N

2

. The response is time dependent, with the characteristics of a diffusion-

controlled process.

9. ZnO nanorods appear well suited to the detection of O

3

. They are sensitive at temperatures as

low as 25°C to percent levels of O

3

in O

2

. The recovery characteristics are quite slow at room

temperature, indicating that the nanorods can be used only for the initial detection of ozone.

10. Single ZnO nanorods with excellent photocurrent response and I–V characteristics hav ...