Effect of aluminum doping on the structural, optical and electrical properties of ZnO thin films processed under thermal shock conditions

The structural, morphological, optical, and electrical properties of Al-doped ZnO thin films annealed under thermal shock conditions were studied. The films were prepared using the sol-gel method and deposited on glass substrates by dip-coating technique. The effects of varying the concentration of aluminum (Al) were analyzed using X-ray Diffraction (XRD), scanning electron microscope (SEM), UV-Vis, and the 4-point probe method. The XRD data demonstrated a degradation in the crystalline structure of the films and the emergence of other preferred directions (100) and (101), which supported the creation of a hexagonal wurtzite structure. The SEM images supported the findings of the XRD analysis. The best electrical and optical performance was obtained for an Al concentration of 1 at%, where the resistivity value was 0.191 omega.cm and the band gap was 3.26 eV, with a high transmittance greater than 90%. The findings of this study render the developed thin-film architecture a viable candidate for high-performance optoelectronic applications.