Influence of surface texture by NH4Cl aqueous solution on the electrical and optical properties of Al-doped zinc oxide films

Aluminum-doped zinc oxide (AZO) films were prepared on glass substrate by mid-frequency direct current reactive magnetron sputtering (MF-DC-MS). The influence of surface texture by NH4Cl aqueous solution on the surface morphology, electrical and optical properties of the AZO films was systematically investigated by scanning electron microscope, four-point probe and ultraviolet-visible-near infrared spectrophotometer, respectively. The results indicate that textured AZO film obtains a better texture surface for light trapping. The reflectivity for textured AZO film decreases drastically in visible light region and the electrical resistivity increases, which can be explained by the textured surface morphology of AZO film. The results above prove that NH4Cl aqueous solution is an appropriate candidate for AZO wet etching because of its easy control and relatively low cost.