Substrate temperature and thickness dependence of properties of boron and gallium co-doped ZnO films

Abstract

Transparent conducting oxide films of boron and gallium co-doped ZnO (BGZO) were prepared on glass substrates by radio frequency magnetron sputtering at room temperature and 200°C, respectively. The dependence of structural, electrical and optical properties on the thickness and substrate temperature were investigated. All films demonstrated c-axis preferred orientation and showed highly transparent in the visible wavelength region. With the increase thickness and substrate temperature, the grain size of BGZO films increased and the full width at half maximum decreased, the carrier mobility increased and resistivity decreased, which indicated that the crystallinity and conductivity of films were improved. The research also found that the optical band gap (E_g) of BGZO thin films decreased with increased substrate temperature and thickness.

Keywords:

• Boron and gallium co-doped ZnO
• Magnetron sputtering
• Substrate temperature
• Thickness

Acknowledgements

This work was funded by the National Natural Science Foundation of China under Grant No. 61176072. The authors also thank Instrumental Analysis and Research Center of Shanghai University for the XRD and SEM work carried out.