Effects of Cu doping and deposition atmosphere on structural, electrical, optical and magnetic properties of ZnO films

ZnO and Cu-doped ZnO (CZO) films were prepared in Ar and Ar + H2 atmospheres at substrate temperature of 300 degrees C, and their structure and opto-electromagnetic properties were investigated by XRD, AFM, Raman spectra, XPS, resistivity, transmittance spectra, PL spectra and hysteresis loop. Compared with ZnO films, CZO films show lower Eg and luminescence intensity but larger resistivity under both atmospheres. For both films, introducing H2 during deposition decreases film thickness, crystallinity, surface roughness and resistivity, but increases transmittance and Eg. After introducing H2, Zni content of both films increases and violet-blue emission enhances. Meanwhile, ZnO film shows decreased VO content, almost unchanged UV emission and abated green-yellow emission, but CZO film displays increased VO content and enhanced UV and green-yellow emissions. All films exhibit ferromagnetism, and Cu doping or introducing H2 increases Ms. The influence mechanisms of Cu doping and introducing H2 on structure and properties of ZnO films were discussed.