Large enhancement of photocatalytic activity in ZnO thin films grown by plasma-enhanced atomic layer deposition

Abstract

In this work, we present a large, tenfold enhancement in the photocatalytic activity of thin ZnO films grown by plasma-enhanced atomic layer deposition (PE-ALD) at 100 °C, compared to values obtained for thin ZnO films deposited by a conventional thermal ALD method at the same temperature. Thus, we have demonstrated that we can deposit thin ZnO films using the PE-ALD method both at low temperatures and with a high photocatalytic ability. A number of structural (SEM, EDX, HRTEM, GIXRD, XRR, XPS, SIMS) and optical (UV-Vis, PL) experimental techniques have been employed to elucidate a possible physical origin of the observed remarkable difference in the photocatalytic activity of thin ZnO films grown by the PE-ALD method compared to those grown by the thermal ALD method.