Nanocrystalline zinc oxide thin films prepared by electrochemical technique for advanced applications

Abstract

Nanocrystalline zinc oxide thin films have been successfully prepared by electrodeposition onto copper substrates using zinc nitrate aqueous solutions at various bath temperatures (30°C-75°C). The deposition was conducted using both using chronoamperometric and chronopotentiometric techniques. Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) techniques were also performed to understand the deposition process. The effects of operating temperature, solution composition, agitation and deposition potentials on the electrochemical measurements and ZnO film characteristics were fully analysed. The findings reveal that temperature and zinc ion concentration have a strong promoting effect on ZnO film formation. Structural characterisation by X-ray diffraction indicates the formation of ZnO phase and the deposited film exhibits the wurtzite structure with crystallite size around 44 nm. Scanning electron microscopy images taken under optimum deposition conditions show smooth and compact ZnO films.