Zinc oxide (ZnO) is a wide band-gap semiconductor with a direct band gap , large exciton binding energy of 60 meV, which can be doped to show a resistivity of 4.4 × 10 -3 Ω • cm at room temperature. These properties make it of interest as a potential material for applications in gas sensors (4), transistors , LEDs , photocatalysis , ultraviolet lasers and also in solar energy conversion . The controlled derivation of nanoscale shapes and different morphologies is of great interest because of the possibility of tuning the physico-chemical properties of these materials re-lated to their surface properties and states. ZnO nanostructures can be synthesized in a number of ways. Based on the most commonly used approaches we can propose the division to vacuum and chemical methods, both of which have their own advantages and yield different properties of the materials. The chemical methods focus mainly on obtaining nanostructured ZnO by wet methods such us sonochemical , sol-gel , solvo-or hydrothermal or organometallic approaches , etc, leading to the formation of nanostructures and nanoparticles. Vacuum methods focus more on thin, uniformly dense films grown by means of atomic layer deposition or epitaxial techniques , pulsed laser deposition or magnetron sputtering .