Effect of growth temperature on the properties of Nb-doped ZnO thin films grown on glass substrates

Nb-doped ZnO (NZO) films were prepared on glass substrates at various deposition temperatures by using the radio-frequency magnetron sputtering method. All the NZO films showed a significant dependence on the growth temperature. The optimum growth temperature, which was determined from the figure of merit, for depositing high-quality NZO films was found to be 300 °C; the NZO thin film formed at this temperature showed a highly-preferential c-axis orientation with a thickness of 1040 nm, a grain size of 65 nm, a bandgap energy of 3.26 eV, an average optical transmittance of 87.9%, and an electrical resistivity of 6.6 × 10−3 Ω·cm. These results indicate that the growth temperature plays an important role in the fabrication of NZO films and devices.