Applications of light scattering in dye-sensitized solar cells

Abstract

Light scattering is a method that has been employed in dye-sensitized solar cells for optical absorption enhancement. In conventional dye-sensitized solar cells, large TiO(2) particles with sizes comparable to the wavelength of visible light are used as scatterers by either being mixed into the nanocrystalline film to generate light scattering or forming a scattering layer on the top of the nanocrystalline film to reflect the incident light, with the aim to extend the traveling distance of incident light within the photoelectrode film. Recently, hierarchical nanostructures, for example nanocrystallite aggregates (among others), have been applied to dye-sensitized solar cells. When used to form a photoelectrode film, these hierarchical nanostructures have demonstrated a dual function: providing large specific surface area; and generating light scattering. Some other merits, such as the capability to enhance electron transport, have been also observed on the hierarchically structured photoelectrode films. Hierarchical nanostructures possessing an architecture that may provide sufficient internal surface area for dye adsorption and meanwhile may generate highly effective light scattering, make them able to create photoelectrode films with optical absorption significantly more efficient than the dispersed nanoparticles used in conventional dye-sensitized solar cells. This allows reduction of the thickness of the photoelectrode film and thus lowering of the charge recombination in dye-sensitized solar cells, making it possible to increase further the efficiency of existing dye-sensitized solar cells.

Dual-functional zinc oxide aggregates with reaction time-dependent morphology as the dye-adsorption layer for dye-sensitized solar cells

“…The enhanced amount of the IPCE value is much higher than that of the dye loading amount for the ZnO nanoflower aggregates with compared to other cases, indicating the better performance for the ZnO nanoflower aggregates-based DSSC is not only due to the higher dye loading but to the better light scattering ability, caused by the presence of larger flower-shaped ZnO aggregates. The results are in good agreement with the literature [30,31]. Typically, light scattering occurs with the particles larger than 200 nm in diameter [32].…”

Efficient photoelectrochemical hydrogen production from bismuth vanadate-decorated tungsten trioxide helix nanostructures

“…The magnitudes of the electric fields inside the WO 3 thin film, the stack of nanoparticles and the nanorod show waveguide-like periodic profiles caused by interference between the incident and reflected waves with negligible scattering effects. The relatively higher magnitude of the electric field for the stack of nanoparticles than for the thin film and the nanorod is due to the reduced effective refractive index caused by the combination of the WO 3 nanoparticles and the air medium, which results in negligible scattering because the nanoparticles are much smaller than the wavelength of light 27 . However, a much more complex distribution of the electric field with an B3-fold higher amplitude than that of the other structures is observed for the threedimensional nanohelices due to their greater light-scattering cross-section.…”

Well-connected TiO2 nanocrystals via solid-state reaction for dye-sensitized solar cells

“…However the reflectance of the film B is much higher than the other two films (A and C), which indicate the improvement of the light harvesting of the photoanode. According to the Mie-theory, when the particle size is appoaching to the incident light wavelength, the particle has a stronger scattering capacity [36]. As mentioned and indicated in Fig.…”