Study of Cu-doped SnO thin films prepared by reactive co-sputtering with facing targets of Sn and Cu

• Cu-doped SnO films were prepared by reactive co-sputtering with facing targets.
• Mixed phase of Cu2O and Cu in tetragonal SnO phases was found.
• The Sn1 − xCuxO film at x = 22 at.% shows the p-type with a mobility of 1.1 cm2/Vs.
• Proper ratio of Cu2O/Cu is imperative to realize the p-type conduction.

The properties of Cu-doped SnO thin films with various Cu contents (Sn1 − xCuxO) prepared by reactive co-sputtering using facing targets of Sn and Cu are investigated. The XRD patterns show the tetragonal SnO phases including the mixed phase of Cu2O (200) and metallic Cu (111). The XRD phase ratio of Cu2O/Cu increases from 0 to 41/59 for x = 3 to 22 at.%, which is compatible with the values of the content ratio of Cu1 +/Cu0 estimated from the XPS peaks. The decrease of the resistivity and the optical transmission with increasing Cu content in Sn1 − xCuxO thin films up to 17 at.% is mainly attributed to the Cu phase. Such behavior of results displays the n-type conduction, whereas the Sn1 − xCuxO thin film at x = 22 at.% shows the p-type conduction with Hall mobility of 1.1 cm2/Vs and the resistivity of 0.45 Ωcm.