Effects of grain boundary scattering on carrier transport of highly transparent conductive Ga-doped ZnO polycrystalline films.

Polycrystalline Ga-doped ZnO films (GZO) with different thicknesses ranging from 100 to 400 nm were deposited by ion plating with DC arc discharge at a glass substrate temperature of 200 °C. The dominant role of grain boundary scattering in carrier transport in the films was demonstrated by varying the film thickness and grain size. With increasing film thickness, the grain size increases and the alignment of the c-axis between the columnar grains is improved. A comparison of Hall mobility and optical mobility showed that for GZO films, carrier transport is mainly limited by grain boundary scattering. By comparing a grain-size-effect theory with electrical resistivity data, we found that the grain boundary resistance coefficient deceases with increasing grain size.(© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]