Surface roughening and transport properties in the growth of nano-structured nickel electrodeposits on ITO substrate

Abstract

We here show that indium tin oxide (ITO)-coated glass can be an interesting substrate for the electrodeposition of separated nickel crystallites growing in the face-centred cubic (fcc) structure. The resulting bi-modal film surface morphology corresponds to the formation of vertical crystallites whose size can reach 400 nm mean height. The topography study confirms the occurrence of both the lateral and vertical growth orientations as the growth exponent coefficient always remains β > 0.50, which is characteristic of such an effect. We also show that the model of link between the topography and surface transport properties is relevant here, which gives it a more general validity. The surface diffusion of the Ni ad-atoms on ITO range in the interval 10 −10 < D s < 10 −9 cm 2 s −1 that is higher than the values obtained on metal substrates. The increase of J favours the vertical growth as the surface diffusion length, Λ s , decreases with the increase of the crystallites size.