A Comparative Investigation of Dye-Sensitized Titanium Dioxide (TiO2) Nanorods Grown on Indium Tin Oxide (ITO) Substrates by Direct and Seed-Mediated Hydrothermal Methods

Abstract

We report a comparative investigation of the characteristics of modified TiO 2 nanorods grown on conducting indium tin oxide glass (ITO) substrates by two different hydrothermal methods: the direct method by which rutile TiO 2 nanorods were grown directly on plain ITO substrates and the seed-mediated one using which a thin film of anatase TiO 2 seed layer was laid down by spin coating and annealing prior to the growth of TiO 2 nanorods on it. Microstructural analysis of the samples using X-ray diffraction confirmed their rutile nature. The average crystallite size estimated using Scherrer's formula was found to fall in the range of 11-17 nm in both cases. Field emission scanning electron microscopy revealed the nanorod morphologies of a dandelion arrangement in the case of directly grown ones and a proper vertical orientation in the case of the seed-mediated method. UV-Vis spectroscopy analysis of both the samples exhibited redshifts with intense absorption of visible radiation, and the seed-mediated one was found to possess an increased bandgap. The transport nature of the samples was characterized by significant increase in both dark and photocurrents. The results show that the dark and photocurrent values of the directly grown TiO 2 nanorods were greater than those of the seed-mediated ones by *seven and five folds, respectively, and therefore, it could serve as efficient photoelectrodes in dye-sensitized solar cells.

The Optical and Crystallite Characterization of Bilayer TiO2 Films Coated on Different ITO layers

“…They should be as follows: ITO-1 and ITO-3 was annealed at 300 o C, ITO-2 and ITO-4 was annealed at 400 o C. According to crystallite size values determined by Equation 3, it can be said that crystallite size decreases with increased annealing temperature at 400 o C. ITO-1 and ITO-3 were deposited via DCMS method in different sputtering gas ambiance. ITO-2 was obtained when the ITO-1 at 300 o C was annealed at 400 o C, ITO-4 was obtained when the ITO-3 at 300 o C was annealed at 400 o C. As seen from Figure 3, the peak intensities of ITO patterns increase with the increasing film thickness [36]. Also, this result supports the Bragg Law given by Equation 4 [31].…”

Phase Composition, Microstructure, and Optical Characteristics of Spin‐Coated La‐TiO2 and Fe–TiO2

“…The peak centered at 32.0° can be associated with the ITO‐coated glass substrate. [ 31,32 ] The formation of anatase TiO 2 was also observed in the DTA‐TG plot shown in Figure 1. The characteristic peaks of anatase TiO 2 are still present when 5 and 7.5 mol% of La ions were added but with decreased intensities.…”

Application of Bunchy TiO2 Hierarchical Microspheres as a Scattering Layer for Dye-Sensitized Solar Cells

“…For example, the thin TiO 2 photoelectrode can absorb dye sensitizer, transfer photo generated electrons to the conductive substrate fluorine-doped tin oxide (FTO) and promote the diffusion of electrolyte into the adsorbed dye (Steffy et al, 2017;Maurya et al, 2019). Among the semiconductor metal-oxides, nanostructures TiO 2 materials have been widely utilized as an efficient mediator to transfer electrons and promote the separation of photoinduced electron-hole pairs in the working electrode of the DSSCs (Jadhav et al, 2014;Chandrakala et al, 2016). In the past few years, a lot of studies had been concentrated on design and preparation of excellent TiO 2 photoanode materials.…”