The aim of this study is to boost the power conversion efficiency of a dye-sensitized solar cell (DSSC) by using the co-sensitization strategy with appropriate natural dyes extracted from pomegranate, beetroot and cranberry. The fabricated DSSCs were evaluated using current–voltage characteristics and UV-Vis spectroscopy. The co-sensitized DSSC with beetroot and cranberry showed higher short-circuit current density and power conversion efficiency than their individual dye-based DSSCs. This improvement in the performance is due to the lower aggregation of the dyes, broader absorption in the visible region and lower value of impedance. However, co-sensitized DSSCs of pomegranate with beetroot and cranberry did not show any improvement in performance.

Dye-sensitized solar cells (DSSCs) are made of manganese dioxide (MnO₂) and Ag-doped manganese dioxide (Ag-MnO₂) counter electrodes (CEs). Herein, MnO₂ and Ag-MnO₂ were synthesized using the hydrothermal method and deposited through the drop casting technique. Electrical characterizations were performed to obtain the fill factor (FF), short-circuit current density (J_SC), open-circuit voltage (V_OC), and power conversion efficiency (PCE). Frequency- and voltage-dependent impedance spectroscopy were performed to gain an insight into the charge transport characteristics. DSSCs fabricated with a MnO2-coated electrode gave a PCE of 2.86% with a V_OC of 0.60 V and a J_SC of 8.72 mA/cm², while DSSCs fabricated with Ag-MnO₂ CEs demonstrated a higher PCE of 3.05%, with a V_OC of 0.66 v and a J_SC of 13.3 mA/cm². The obtained results indicate that Ag-doped MnO₂-coated counter electrodes have the potential to replace expensive Pt=coated counter electrodes.