Structural, electrical, and optical properties of Zn_1-xSn _xO thin films deposited by reactive co-sputtering

Zn_1-xSn_xO thin films were deposited on K9 glass and Si substrates by co-sputtering Zn and Sn targets under atmospheres of Ar and O₂. The samples were then characterized with X-ray diffraction (XRD), Raman, energy-dispersive X-ray spectroscopy (EDX), Seebeck effect, four-probe instrument, and UV/VIS spectrophotometry. XRD and Raman show that all the samples are hexagonal and Sn doping increases the stress greatly. EDX demonstrates that the atomic ratio of Sn to Sn plus Zn is 0.04-0.07. All the samples are n-type. The resistivity of Zn_1-xSn_xO is much smaller than that of undoped ZnO deposited under the same conditions. The optical bandgap of Zn_1-xSn_xO is also reduced compared with that of ZnO deposited under the same conditions.