Abstract
ZnO thin films were prepared by sol-gel spin coating technique, and the effect of microwave-assisted thermal annealing on structural and optical properties was investigated. Structural features, microstructural morphology and optoelectronic properties were studied using XRD, FE-SEM, UV-visible spectrophotometry and four-point probes measurement system. During microwave-assisted annealing, rapid volumetric heating preserved nanostructure along with pore-free dense morphology. Also, this annealing technique induced larger tensile strain and increased preferential orientation along (002). Power consumption for sintering was reduced as obvious from the decreased annealing time. An increase in optical band gap with a decrease in electric resistivity by one order of magnitude can be attributed to its nanostructured pore-free structure, and the induced strain resulted from microwave-assisted annealing.