Preparation and characterization of vertical regular arrayed and needle-shaped irregular titanium dioxide nanotubes for dye-sensitized solar cells

Abstract

This study investigated the effect of surface modification on the photovoltaic characteristics of TiO2 electrodes. The modification was done by increasing the TiO2 nanoparticles in order to increased dye absorption. The crystal phase features, morphology, and topography were assessed through such techniques as XRD, SEM, and AFM. This addition was done with several methods including ultrasonic bathing, spin-coating and immersing in an autoclave that among these techniques autoclave has the highest efficiency. Furthermore, TiO2 nanotubes (TNTs) and needle-shaped irregular nanotubes were designed on Ti sheet and Ti layer deposited on FTO glass. The characterization results point to a maximum efficiency of 2.5% that belongs to the solar cells composed of TiO2 nanotube photoanodes in TNTs on Ti layer sputtered on FTO glass. In the sample of solar cells with TiO2 nanotubes photoanode, which TNTs were designed on Ti sheet, the efficiency was 1.24%. Finally, for solar cells composed of TiO2 nanotube photoanodes with needle-shaped irregular nanotube arrays designed on Ti layer sputter upon FTO glass and TiO2 nanotube photoanodes with a needle-shaped irregular nanotube array designed on Ti sheet, the efficiencies were respectivly 0.54% and 0.44%.