Pulsed electrochemical deposition has been employed to grown high-quality ZnO films. As a function of the reduction potential, related to the OH-/Zn2+ ratio in the local pH at the electrode surface, different morphologies have been obtained. Structures as hexagonal columns, hexagonal platelets, flowers and 2D planar film were observed. Kelvin probe force microscopy (KPFM) with NT-KP tips (from NEXT-TIP) can simultaneously measure topographic and contact potential images obtaining conductive properties and high spatial resolution. Moreover, the improvement in the electrical and topographical resolutions, the NT-KP tips can be regenerated after a non-desired crash with the surface. This characteristic is especially important because the ZnO films have a large scanned area and relative roughness. Due to these measurements, it is found electrical conduction depends on the grain boundaries for the ZnO films grown.

C. V. Manzano, O. Caballero-Calero, S. Hormeño, M. Penedo, M. Luna, and M. S. Martín-González, Journal of Physical Chemistry C, 117 (2012) 1502. DOI: 10.1021/jp3107099.