Poriferous microtablet of anatase TiO2 growth on an ITO surface for high-efficiency dye-sensitized solar cells

A liquid-phase deposition method enables the synthesis of a unique anatase TiO2 structure, which consists of poriferous microtablets with a hairy nanowire skin and a body constructed by a brick-like assembly of nanocuboids, directly onto an ITO substrate. The poriferous TiO2 microtablets (PTM) have square-shaped, rounded vertices, edges that are 10µm in length and a thickness of approximately 5μm. They can be grown at a high density onto an ITO surface from a growth solution that contains ammonium hexafluoro titanate and boric acid. The nanowires that decorate the PTM surface have a diameter of 10nm and a length of approximately 200nm. Its bulk structure is constructed from a brick-like assembly of nanocuboids with a width, length and thickness of approximately 10, 20 and 5nm, respectively. The driving factor for the formation of this structure is oriented attachment under kinetic control. The preliminary results of the application of this structure in dye-sensitized solar cell (DSSC) devices indicate a power conversion efficiency as high as 3.0%. Because the active surface area in the PTM is large enough for dye adsorption (for a typical dye loading as high as approximately 936nmol/cm2) and surface reactions, a high-efficiency DSSC device may be achievable using this new structure if the optimum conditions are obtained. •Poriferous TiO2 microtablets, a new structure of anatase TiO2 for dye-sensitized solar cell.•A novel method for the preparation of high-surface area TiO2 nanostructures.•Poriferous TiO2 microtablets exhibit extremely high dye-loading, potential for high-efficiency dye-sensitive solar cell.