Growth of Oriented Single-Crystalline Rutile TiO₂ Nanorods on Transparent Conducting Substrates for Dye-Sensitized Solar Cells

Abstract

Dye-sensitized solar cells (DSSCs) made from oriented, one-dimensional semiconductor nanostructures such as nanorods, nanowires, and nanotubes are receiving attention because direct connection of the point of photogeneration with the collection electrode using such structures may improve the cell performance. Specifically, oriented single-crystalline TiO(2) nanorods or nanowires on a transparent conductive substrate would be most desirable, but achieving these structures has been limited by the availability of synthetic techniques. In this study, a facile, hydrothermal method was developed for the first time to grow oriented, single-crystalline rutile TiO(2) nanorod films on transparent conductive fluorine-doped tin oxide (FTO) substrates. The diameter, length, and density of the nanorods could be varied by changing the growth parameters, such as growth time, growth temperature, initial reactant concentration, acidity, and additives. The epitaxial relation between the FTO substrate and rutile TiO(2) with a small lattice mismatch plays a key role in driving the nucleation and growth of the rutile TiO(2) nanorods on FTO. With TiCl(4)-treatment, a light-to-electricity conversion efficiency of 3% could be achieved by using 4 mum-long TiO(2) nanorod films as the photoanode in a DSSC.

Hierarchically Structured Microspheres for High-Efficiency Rutile TiO2-Based Dye-Sensitized Solar Cells

“…In general, the (110) crystal plane is perpendicular to the (001) crystal plane, and thus the nanoneedles grew along the (110) crystal plane with a preferred [001] orientation. 40 Moreover, Figure 3 shows the Raman spectrum of TiO 2 microspheres prepared by chemical bath process for 12 h, indicating that the as-prepared sample possesses rutile phase according to the characteristic Raman modes at 132 cm −1 (B 1g ), 440 cm −1 (E g ), and 608 cm −1 (A 1g ) with a broad band near 240 cm −1 assigned to a second-order phonon. 41,42 The X-ray diffraction (XRD) analysis also showed that the microsphere films were pure rutile TiO 2 .…”

High Discharge Energy Density at Low Electric Field Using an Aligned Titanium Dioxide/Lead Zirconate Titanate Nanowire Array

“…It can be observed that the TiO 2 nanowire array is uniformly distributed on the FTO substrate and had preferred orientation in the [001] direction. It is believed that FTO substrate plays an important role in generating the 1D structure by promotion of epitaxial nucleation and growth in the [001] direction due to the small lattice mismatch between the rutile structures of FTO and TiO 2 16. The morphologies of the synthesized TiO 2 @PZT nanowire arrays were tuned by modulating the concentration of Ti source from 0.03 to 0.06 mol L −1 , as shown in Figure S1 in the Supporting Information.…”

“…Table 1 summarizes the performance of some typical polymer‐based dielectric composites with the electric field. The large energy density at such a low electric field in these nanocomposites can be attributed to (i) the dual phase nature of the TiO 2 @PZT nanowire array, which results in large interfacial regions and hence large interfacial polarization;24, 25 (ii) the highly oriented nanowire also plays an important role in increasing the polarization and electromechanical coupling of the nanocomposites;6, 16 and (iii) the obtained high permittivity of the nanocomposites yields high saturation polarization (Equation (3)), and the nanocomposites possess narrow hysteresis loops with low values of P r as shown in Figures S5–S7 (Supporting Information), which lead to largely enhanced P max − P r values.…”

An Integrated Power Pack of Dye-Sensitized Solar Cell and Li Battery Based on Double-Sided TiO2 Nanotube Arrays

“…21 0.4 mL of titanium butoxide was added into the mixture containing 9 mL of deionized water and 9 mL of concentrated hydrochloric acid (36%-38% by weight) slowly. After stirring for 30 min, the as-prepared mixture was put into a 25 mL Teflon-lined stainless steel autoclave.…”