Applications and synthesis of zinc oxide: An emerging wide bandgap material

Zinc oxide, an important metal oxide, is a wide bandgap II-VI semiconductor material with large exciton binding energy of 60 meV at room temperature. Zinc oxide has some unique characteristics like large piezoelectric constant, stability at higher temperature, and suitability for a variety of nanostructures. It has potential applications in several optics and optoelectronics technologies including display panels, electroluminescent and photovoltaic devices, thermoelectric devices, and nanogenerators. We present a short review on synthesis of zinc oxide emphasizing on MOCVD which is the most popular method to grow ZnO. Few applications of zinc oxide have also been discussed very briefly. Previously reported significant results about MOCVD growth of zinc oxide are discussed in detail. Also, we have grown zinc oxide thin films with different thicknesses on sapphire substrates using MOCVD. It has been observed that crystal quality degrades with increase in thickness of the film due to lattice mismatch and growth rate substantially decreases with increase in chamber pressure.