KNbO₃ photoelectrode for DSSC: a structural, optical and electrical approach

In this work, we present the potassium niobate (KNbO3) nanoparticles as a suitable mesoporous photoelectrode for dye-sensitized solar cells (DSSCs). The KNbO3 particles were synthesized by the microwave-assisted hydrothermal method using mild conditions and characterized by SEM, XRD, Raman, and UV-Vis diffuse reflectance. The particles presented a pyramidal tower-like shape with an orthorhombic structure and an indirect bandgap of (3.0 +/- 0.1) eV. Dye-sensitized solar cells were assembled using the synthesized KNbO3 nanoparticles, which were deposited as a photoelectrode on a TiO2 recombination charge blocking layer. It is noticeable that the synergistic operation of the TiO2 blocking layer and KNbO3 photoelectrode is essential to achieve photovoltaic behaviour in our solar cells. The short-circuit current density of J(sc) = 2.82 mA, open-circuit voltage V-oc = 669 mV, fill factor FF = 0.62, and a power conversion efficiency PCE = 1.17%, reports elevated parameters if compared to other DSSCs alternative materials, becoming potassium niobate suitable as photoelectrode.