Effect of substrate temperature on photoelectric properties of AZO thin films

Herein, Al-doped ZnO (AZO) thin films are prepared on quartz glass substrates by RF magnetron sputtering. The effects of substrate temperature (T${}_s$) on the structure, morphology, electrical, and optical properties of AZO films are investigated by X-ray diffraction, field emission electron microscopy, Hall effect testing instrument, and ultraviolet spectrophotometer, respectively. The results show that the doping of Al element does not change the structure of ZnO films, and all films have typical hexagonal wurtzite structure with preferred c-axis orientation. The film sample has the strongest (002) diffraction peak and the smallest value of full-width at half-maximum at the T${}_s$ value of 150 °C. With the increase of T${}_s$ value, the grain size of the film increases first and then decreases. At 150 °C, the film exhibits good electrical conductivity, and its resistivity is 0.6210${}^{-2}$ Ω cm, the carrier concentration is 9.8410${}^{19}$ cm${}^{-3}$, and the Hall mobility is 13.66 cm${}^2$ V${}^{-1}$ s${}^{-1}$. All samples show high transmittance, and the average transmittance in the stable visible light region is as high as 95% at the T${}_s$ value of room temperature and 250 °C, and the average transmittance of all samples is above 80%. This provides a method for the application of ZnO transparent conductive films. (© 2023 Wiley‐VCH GmbH)