Nanostructured ZnO films prepared by hydro-thermal chemical deposition and microwave-activated reactive sputtering

Nanostructured, highly porous, films of zinc oxide have been prepared by hydro-thermal chemical deposition and by microwave-activated reactive sputtering for applications in sensors and solar cells. Scanning electron microscopy, X-ray diffraction, optical constant measurements, and Raman spectroscopy are presented demonstrating the pronounced effect of microwave power on the nanostructure of films prepared by microwave-activated reactive sputtering and the marked differences between films grown by the two methods. While the structures obtained by hydro-thermal chemical deposition are highly crystalline and grow as nanorods, the microwave activated reactive sputtering films are initially dense with subsequent increase in porosity, leading to unusual cylindrical structures with hemi-spherical caps. (C) 2016 Elsevier B.V. All rights reserved.