Highly-ordered TiO2 nanotube arrays with double-walled and bamboo-type structures in dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) based on free-standing, double-walled TiO2 nanotubes with bamboo-like morphology have been prepared by a sequence of alternating voltage and two-step anodization treatments. The combination of double-walled and bamboo-like morphologies led to an increase in dye loading and an improvement in photoconversion performance. Subsequently, the fabricated dye-sensitized nanotubes used to prepare DSSCs that operate in a frontside illumination mode yielded a significantly high power conversion efficiency of 3.46%, which was approximately two times higher than DSSCs that were fabricated using traditional single-walled TiO2 nanotube arrays with smooth surfaces. In addition, DSSCs fabricated from nanotubes with higher bamboo ring densities exhibited better conversion efficiencies than those prepared from nanotubes with lower bamboo ring densities. The improved conversion efficiency can be attributed to increased dye loading in the combined double-walled and bamboo-like titania nanostructures.

Dye-sensitized solar cells (DSSCs) based on free-standing, double-walled TiO2 nanotubes with bamboo-like morphology have been prepared and investigated. The fabricated DSSCs exhibited a significantly high power conversion efficiency of 3.46%, which was approximately two times higher than DSSCs that were fabricated using traditional single-walled TiO2 nanotube arrays with smooth surfaces.Figure optionsDownload as PowerPoint slideHighlights
► Titania nanotubes with double-walled/bamboo structures were used in solar cells.
► Solar cells from double-walled/bamboo nanotubes show good conversion efficiencies.
► The improved conversion efficiency is due to an increase in nanotube-dye loading.