Layered lanthanum titanate (La₂Ti₂O₇) based recombination blocking layers for dye-sensitized solar cells

Abstract

Using Sol–gel method Lanthanum titanate (La₂Ti₂O₇) nanoparticles was synthesized and its performance as recombination blocking layer in dye-sensitized solar cells (DSSC) was studied. Formation of Monoclinic phase La₂Ti₂O₇ was confirmed from X-ray diffraction (XRD) and Raman analysis respectively. Samples morphology studied through Field Emission Scanning Electron Microscope (FE-SEM) and High-Resolution Transmission Electron Microscopy (HRTEM) revealed the layered structure of the material. The elemental composition of La₂Ti₂O₇ were confirmed by Energy Dispersive X-ray Analysis (EDAX)_, and the Selected Area Electron Diffraction (SAED) pattern revealed the polycrystalline nature of a material. UV–VIS and photoluminescence spectroscopies were used to study its light absorption and emission properties respectively. Furthermore, the photovoltaic performance of the La₂Ti₂O₇ based blocking layers in DSSCs was evaluated through J-V characterization and its charge kinetics were studied using Electrochemical impedance spectroscopy (EIS) respectively. These findings suggest that La₂Ti₂O₇ has promising capabilities as an effective recombination-blocking layer at the photoanode/electrolyte interface in dye-sensitised solar cells.