ZnO Nanoparticles: Synthesis Techniques, Properties and Applications

ZnO nanoparticles have been a subject of intensive studies in recent years due to their unique material properties and wide applications, in electronics, photonics, cosmetics, biosensors, rubber industry, pigments etc. ZnO is a direct wide band gap semiconductor having band gap energy of 3.37 eV and a large exciton binding energy of 60 meV at room temperature making it a prospective candidate for many applications such as UV lasers, light-emitting diodes, solar cells, nanogenerators, gas sensors, and photodetectors. Several novel and cost effective techniques have been employed by researchers in the synthesis of ZnO nanoparticles. The paper presents a review of the most important chemical, physical and biological techniques used in the synthesis of ZnO. The various useful properties of ZnO that has captured much attention owing to which it has found wide applications in different technological domains have also been discussed.