X-ray absorption of Zn1−xCoxO thin films: A local structure study

In this study, the application of synchrotron radiation microprobe to the analysis of Co incorporation in Zn1−xCoxO is reported. From the Co and Zn fluorescence line intensity ratio, the Co concentrations were deduced. A combination of fluorescence mapping with x-ray absorption spectroscopic techniques made possible to examine not only the uniform elemental distribution but also the short range structural order with the Co content. In Zn1−xCoxO films grown by pulsed laser depositions the Co atoms are in tetrahedral site configuration, corresponding to a substitutional site in wurtzite structure. Within the experimental accuracy, no significant bond length deviation from the pure ZnO structure was observed in the considered compositional range.