Novel three-layer TiO2 nanoparticle stacking architecture for efficient dye-sensitized solar cells

Abstract In this work, we report a novel three-layer TiO 2 nanoparticle photoelectrode for dye-sensitized solar cells (DSSCs). In such a DSSC, a very thin front scattering layer (∼1 μm thick) composed of small nanoparticles (∼20 nm) and larger scattering nanoparticles (>100 nm) is inserted in front of the typical small-nanoparticle absorption layer and the large-nanoparticle back-scattering/reflection layer. Such a very thin front scattering layer having mixture of small/large nanoparticles provides a larger haze (i.e., stronger scattering) and yet still retains a high integrated transmittance. With effectively scattering portion of the incident light into larger oblique angles and therefore increasing optical paths and absorption, DSSC efficiencies are enhanced by 15.2%, compared to the conventional two-layer DSSCs.