Hydrothermal Synthesis of TiO₂ Porous Hollow Nanospheres for Coating on the Photoelectrode of Dye-Sensitized Solar Cells

Abstract

Various sizes of TiO2 hollow nanosphers were synthesized by a hydrolysis followed by the hydrothermal treatment using different water content and titanium isopropoxide (TTIP) while the remaining components such as methylamine, ethanol and acetonitrile were kept as a constant. We synthesized the various sizes of spheres, 150, 250, 400, 450, and 600 nm in diameter; those are represented as SP150, SP250, SP400, SP450, and SP600. The prepared spheres diameters were confirmed by scanning electron microscopy (SEM). These spheres were coated by using a simple spray technique with the TiO2 colloidal solution as a scattering layer for the TiO2 photoelectrode of dye-sensitized solar cells. Optical absorption measurements did not find a difference in the dye adsorption amount with and without the scattering layer. The scattering effect was observed by incident photon to current conversion efficiency (IPCE) measurements especially in the wavelength region of 550–700 nm. The current–voltage (I–V) measurements show that the scattering layer with 450 nm spheres coated on the photoelectrode gave the improved photovoltaic performances compared to other diameters of the spheres. In the present study, the best energy conversion efficiency of 9.56% was obtained for the photoelectrode with the scattering layer, while the pure photoelectrode without the layer gave 8.4%.

A novel poly(acrylonitrile)/poly(ethylene glycol)-based polymer gel electrolyte for high efficiency dye sensitized solar cells

“…2(d) indicates good contact between the spheres as a result of mixing of Tyco colloidal solution during the spray pyrolysis method. These connections formed by the colloidal solution particles in between the spheres enhance the electrical conductivity by increasing the charge transfer rate of the photoelectrode 47 and offer excellent light harvesting efficiency as the microspheres act as a good scattering layer. 51…”

“…The In contrast, with the increasing PEG content in PAN/PEG, the open circuit voltage (V oc ) of the DSSCs increases rapidly, as mentioned in the previous report. 47 The formation of the crosslinked polymer on the TiO 2 photoelectrode surface reduces the back-transfer of electrons from the conduction band of TiO 2 to the I 3 À ion in the electrolyte. Hence, the V oc of the cell improved.…”

Growth of Aligned Single-Crystalline TiO2 Nanorod Arrays on Transparent Conducting Oxide Coated Glass

“…TiO 2 is one of the most attractive semiconductors due to its wide band gap (3.0-3.2 eV), non-toxicity, low cost and physicochemical stability. It has been widely used for lithium batteries, 1,2) gas sensors, 3) photocatalysts, 4) solar cells, [5][6][7][8] photodetectors, 9) and transparent conducting oxide 10) applications. For photoelectrical applications, various nanostructures, like nanoparticles, 11) nanotubes, 12) nanorods 13) and hollow spheres, 6,14) have attracted much attention due to their high surface area.…”

“…It has been widely used for lithium batteries, 1,2) gas sensors, 3) photocatalysts, 4) solar cells, [5][6][7][8] photodetectors, 9) and transparent conducting oxide 10) applications. For photoelectrical applications, various nanostructures, like nanoparticles, 11) nanotubes, 12) nanorods 13) and hollow spheres, 6,14) have attracted much attention due to their high surface area. The use of one-dimensional nanostructures instead of nanoparticle films in photoelectrochemistry has also been considered.…”