Photovoltaic and Impedance Analysis of Dye-Sensitized Solar Cells with Counter Electrodes of Manganese Dioxide and Silver-Doped Manganese Dioxide

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 (JSC), open-circuit voltage (VOC), 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 VOC of 0.60 V and a JSC of 8.72 mA/cm2, while DSSCs fabricated with Ag-MnO2 CEs demonstrated a higher PCE of 3.05%, with a VOC of 0.66 v and a JSC 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.