Development of uniformly grown ZnO micro-particles structures by simple and cost-effective chemical drop method

摘要

A simple and cost-effective chemical drop method has been developed and adopted for the synthesis of zinc oxide (ZnO) structures. The depositions were carried out at different substrate temperatures increased from 100 to 250 °C on glass substrates by dropping an equimolar solution consisting of zinc nitrate hexahydrate and hexamethylenetetrarnine dissolved in deionized-water with a concentration of 5 mM. The structures grown at 200 °C showed nanoparticles (NPs) composed micro-particles (MPs) like surface morphology and exhibited hexagonal crystal structures having a preferential orientation of (002). However, these structures have polycrystalline nature and zinc deficient chemical composition. Raman spectroscopic analyses reveal that the as-deposited ZnO MPs structures at 200 °C have compressive stress and strong polar lattice bonds. The optical studies show that these ZnO structures are highly transparent (92%) in visible region and contain a direct optical band gap of about 3.42 eV.