Influence of the deposition temperature on the physical properties of high electron mobility ZnO films by sol-gel process

Influence of the deposition temperature on the structural, morphological and electrical properties of the sol gel derived nanostructure Zinc Oxide (ZnO) films on p-type Silicon (p-Si) substrates were investigated. X-ray Diffractometer (XRD), Field emission scanning electron microscopy (FE-SEM) and Hall effect measurements were used to characterize the deposited ZnO films. XRD results showed that the films structure exhibited a polycrystalline with hexagonal wurtzite structure and (0 0 2) preferred orientation. The average crystallite size increased from 32 nm to 65 nm. The deposition temperature significantly affected crystallite size, carrier concentration and mobility values. Depending on the increase in the deposition temperature, carrier concentration decreased by approximately three orders of magnitude, mobility increased by two orders of magnitude and reached a high value as 100 cm2/Vs. The change in carrier concentration was discussed with respect to evaporation and chemisorption of oxygen from the grain boundaries.