Aging and doping effects of nano-structured MgxZn1−xO thin films for CNT applications

This paper reports on the preparation of nano-structured of Mg_xZn_1-xO thin films by sol-gel spin coating method which will be used as a template layer to grow carbon nanotubes. The Mg_xZn_1-xO films were deposited on Pt/Si (100) substrates. In this work, we focused on the effect of sol aging and Mg content on the film structure and resistivity. Sols with Mg content of x = 0.1, 0.3 and 0.5 were subjected to aging times of between 3 to 240 hours. X-Ray Diffractometer (XRD), energy dispersive analysis by X-ray (EDAX), scanning (SEM) and field emission scanning electron (FESEM) microscopes were used to characterize the structural properties. Results from SEM and FESEM show the thickness and grain size increased with aging up to 240 hours. XRD spectrum reveals the deposited thin films were polycrystalline wurtzite structure. The element of Mg in the ZnO films was confirmed by EDAX. The electrical resistivity also increased with aging time as confirmed by four point probe method. The results suggest that appropriate aging of the sol is important for improving structure quality and electrical performance of Mg_xZn_1-xO thin films.