Al-doped ZnO (AZO) thin films were grown on glass substrates using radio-frequency magnetron sputtering. X-ray diffraction patterns of the AZO thin films grown on glass substrates showed that the full width at half-maximum of the (0002) peak corresponding to the AZO thin film decreased with an increase in the annealing temperature, indicative of an improvement of the crystal quality of the AZO films. Atomic force microscopy images showed that the root mean square of the average surface roughnesses of the AZO films decreased with an increase in the annealing temperature. Hall effect measurements showed that the resistivity of the AZO film annealed at 250 oC was as small as 8 × 10−4 Ω·cm. The transmittance spectra showed that the average transmittance in the wavelength range between 400 and 800 nm was above 90%. The optical band gap energies of the AZO films were determined from the transmittance spectra.

Keywords: Al-doped ZnO, Thermal annealing, Structural property, Electrical property, Optical property.