Effect of optical and electronic structure on the photocatalytic activity of Al doped ZnO ALD thin films on glass fibers

Abstract

Photocatalytic water treatment can be promising for eliminating toxic pollutants via a more sustainable approach using renewable sources. However, the technique still requires materials design to optimize/maximize the performance of the photocatalytic materials. Immobilizing the thin film photocatalytic materials onto high surface area textile substrates via atomic layer deposition (ALD) can offer a practical design approach. Al-doped ZnO (AZO) ALD films are deposited onto glass fabric substrates, and their photocatalytic performances were investigated in relation to the FESEM, XRD, XPS, UV-Vis, and PL characterizations. The amount of Al and the post-deposition annealing changed the materials structure, thus the photocatalytic activity of the films. Maximum performance was achieved with the 20 % Al-doped ZnO films after a post-deposition thermal annealing step at 450 degrees C. The sample also showed the highest UV-Vis absorption and PL emission among the samples. However, this sample didn't show any crystal peaks in the XRD analysis. Furthermore, the charge carrier concentrations and the mobility of the films were investigated via Hall-Effect, which showed that the 20 % AZO sample has very different features with a p-type nature compared to the other AZO films.