engleski

Photocatalytic Activity of Thin ALD / PE-ALD ZnO Films: a Comparative Study

The synthesis of thin ZnO films using atomic layer deposition (ALD) technique has many advantages over other techniques such as good repeatability, accurate thickness control and great uniformity of the films [1]. The range of the ALD deposition temperatures for ZnO is from 60 °C to 250 °C and it has a huge impact on the photocatalytic activity of the films. For ZnO films deposited by a conventional thermal ALD, it is known that the final photocatalytic activity of the films greatly improves by increasing the temperature of the substrate during the deposition [1, 2]. A less common plasma-enhanced atomic layer deposition (PE-ALD) is usually employed for the deposition of oxide films at lower temperatures. In the present study, we have examined the influence of the deposition temperature on the photocatalytic activity of the ZnO films deposited by the PE-ALD method. In contrast to ZnO films obtained by the thermal ALD, the photocatalytic activity of the films deposited by the PE-ALD method shows a maximum value for films deposited at 80 °C. For higher deposition temperatures the photocatalytic activity gradually decreases. In the comparative study, we have also characterized structural and physical properties of the thermal ALD and the PE- ALD films with scanning electron microscopy (SEM), UV-Vis absorption spectroscopy, x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS).

zinc oxide, thin film, atomic layer deposition, plasma, photocatalysis

nije evidentirano