Synergistic influence of plasmonic Ag nanoparticles/La0.6Sr0.4CoO3/TiO2 heterostructured photoanodes boosted solar energy harvesting by dye-sensitized photovoltaics

Abstract

Several hybrid composite photoanodes composed of easily synthesizable and cost-effective La0.6Sr0.4CoO3 (LSCO) nanoparticles (obtained by the sol–gel method) combined with TiO2 nanoparticles were prepared and investigated for their light-harvesting properties in dye-sensitized solar cells (DSSCs). To develop these effective photoelectrode nanomaterials for DSSCs, the pure inorganic perovskite La0.6Sr0.4CoO3 (2, 4, 6 and 8 %) as well as plasmonic silver nanoparticles decorated La0.6Sr0.4CoO3 (6 % La0.6Sr0.4CoO3/x%Ag, x = 1, 2.5, 5, 7.5 and 10 %) nanomaterials were added into the TiO2 photoanodes. The XRD, FESEM, EDS, BET FT-IR, DRS, PL, and dye loading were used to study all nanostructured photoanodes' structural and morphological properties. Based on the photovoltaic tests, it was found that the DSSC fabricated with TiO2 + 6 % La0.6Sr0.4CoO3 achieved the most enhanced efficiency of 6.04 % among the TiO2 + La0.6Sr0.4CoO3 (2, 4, 6, and 8 %) containing devices. Furthermore, the power conversion efficiency (PCE) values were increased when Ag plasmonic nanoparticles were decorated on the La0.6Sr0.4CoO3 crystalline lattice. The greatest PCE = 7.34 % was attained for the optimized solar cell assembled by TiO2 + 6 % La0.6Sr0.4CoO3/7.5 %Ag photoanode which yielded ∼ 2.35 and 1.21 folds increase in PCE compared to the DSSCs containing pristine TiO2 nanoparticles and TiO2/6% La0.6Sr0.4CoO3 photoelectrodes, respectively. Based on the photoelectrochemical analysis, this structure exhibited the fastest electron transport rate, the most effective photo-induced charge separation, the greatest electron collection efficiency, the highest dye loading capacity, and the least photoluminescence intensity (charge recombination), which all contributed to increasing the DSSC device's efficiency.