ABSTRACT
Zinc oxide (ZnO) is a well-known metal oxide semiconductor widely used in the production of many applications for its excellent properties such as piezoelectricity, transparency and chemical and thermal stability. Some of the unique features of ZnO include ease of fabrication of both n- and p-type material, high electron mobility, wide band gap, compatibility with standard complementary metal oxide semiconductor technology and fairly good lattice matching with silicon (Si) and Si dioxide substrate. Several nanoforms of ZnO, like nanorods, nanowire, nanobelt, nanotube and nanoflakes, have been reported by various researchers across the globe for the different fields of application including sensors owing to its inherent oxygen vacancies. Particularly, nanocrystalline ZnO has its potential application in reducing the operating temperatures and increasing sensitivity as well as improving the response time of gas sensors due to its increased surface-to-volume ratio. In order to improve conductivity, aluminium doping of ZnO may be performed.
