Interpreting the conductive atomic force microscopy measured inhomogeneous nanoscale surface electrical properties of Al-doped ZnO films

In this work, conductive atomic force microscopy is used to study the inhomogeneous surface electrical conductivity of Al-doped ZnO thin films at a nanoscale dimension. To this end, Al-doped ZnO films were deposited onto the soda lime glass substrates at substrate temperature (T<inf>s</inf>) varying from 303 to 673 K in radio frequency magnetron sputtering. The obtained local surface electrical conductivity values are found to be influenced by their bulk electrical resistivity, surface topography and tip geometry. Further, the average (local) surface conductivity from the film surface is found to increase with increasing T<inf>s</inf> from 303 to 623 K, beyond which they decrease until 673 K. Copyright © 2016 John Wiley & Sons, Ltd.