Nanotechnology On Surfaces Laboratory, ICMS Materials Science Institute of Seville, C/Americo Vespucio 49, Seville, Spain, Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, United Kingdom, Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide Spain, Carretera de Utrera km 1, Seville, Spain, University of Grenoble Alpes, Grenoble, France, CEA, LETI, MINATEC Campus, Grenoble, France

This paper addresses the fabrication of vertically aligned ZnO@TiO2 multishell nanotubes by a combined full vacuum-plasma approach at mild temperatures. The growth is carried out within the premises of a one-reactor approach, i.e. minimizing the number of vacuum chambers and sample transferences. In this way, the interface between ZnO and TiO2 is fully preserved from humidity thus increasing ZnO durability and stability. These nanostructures are studied by scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy in STEM (EDX-STEM). High density one-dimensional arrays of these nanotubes formed on FTO substrates are applied as photoanode in a dye-sensitized solar cell (DSC). The evolution of the dye adsorption capacity and solar cells parameters are explored as a function of the crystallinity and thickness of the TiO2 shell. The results show the critical effect of a full coverage by TiO2 of ZnO core to explain the mixed results found in the literature. © 2017 The Author(s).