Influence of 50 KEV Ar+ Ion Beam Irradiation on the Morphology of ZnO Thin Films - A Study on the Semiconductor/Electrolyte Interface for Improved Photoelectrochemical Splitting of Water
Nanostructured thin films of ZnO prepared by RF sputtering technique were successfully irradiated by low
energy (50 KeV) Ar+ ion beam at an incidence angle of 60°. Morphological variation caused in the films due to exposure to
ion beams was quantitatively characterized by Power Spectral Density analysis. Hence, value of rough microscopic features
viz. fractal dimension (DH), lower (ɭ) and upper cut off length scale (L) were determined for all the unirradiated and
irradiated samples. The samples were further analyzed for their photoelectrochemical (PEC) performance for water splitting.
A correlation in the PEC performance and morphological surface features was established. It was found that the sample
irradiated at the fluence of 5 x 1016 ions/cm2 possess maximum surface roughness with fractal dimension of 2.52 and lower
and upper length scales of 14.79 nm and 154.88 nm respectively. This sample exhibited maximum photocurrent density of
2.02 mA/cm2 and applied bias photon-to-current efficiency of 0.25% at 0.4V/SCE.
Keywords - Power Spectral Density, Photoelectrochemical, Low Energy Ion Beam