Low–Temperature Hydrogen Sensors Based on Au Nanoclusters and Schottky Contacts on ZnO Films Deposited by Pulsed Laser Deposition on Si and SiO2 Substrates

Unintentionally doped n-type ZnO thin films deposited on Si and SiO₂ substrates by pulsed laser deposition (PLD) techniques, were functionalized as H₂ gas sensors by a) incorporating Au nanoclusters in the surface, and b) developing Au Schottky diodes on ZnO. The influence of the catalytic action of the Au nanoclusters on the sensing properties of the devices was examined and found to provide faster response times at a reduced working temperature of 150 degC. The field-assisted sensing of the Au Schottky diodes demonstrated for the first time in this system, a more dramatic reduction in the working temperature of the sensor to nearly room temperature