Photoresponse and H2 gas sensing properties of highly oriented Al and Al/Sb doped ZnO thin films

ZnO:Al and ZnO:Al/Sb thin films have been prepared and investigated. The thin films were deposited on Si substrates by the sol-gel method. The structural, optical and electrical properties of ZnO films have been investigated by spectrophotometry, ellipsometry, X-ray diffraction and current-voltage characterizations. It is found that the films exhibit wurtzite structure with a highly c-axis orientation perpendicular to the surface of the substrate, a high reflectivity in the infrared region and a response to illumination. Furthermore, it has been found that Si/(ZnO:Al/Sb)/Al photodiode is promising in photoconduction device while Si/(ZnO:Al)/Al can be used as gas sensor responding to the low H2 concentrations.