First application of CoO nanorods as efficient counter electrode for quantum dots-sensitized solar cells

For boosting the power conversion efficiency (PCE) of quantum dot sensitized solar cells (QDSSCs), metal oxide (CoO) has been prepared via a facile mean and applied for CE materials in CdS/CdSe/ZnS QDSSCs. The electrochemical properties of the CoO counter electrode (CE) and photovoltaic performances of QDSSCs are investigated in detail. Under analogous sunlight illumination, compared with traditional Cu 2 S CE, the QDSSCs fabricated with CoO CE showed an obvious enhancement in cell properties and increased the power conversion efficiency (PCE) by 32.7%. A PCE of 6.02% was achieved by the QDSSCs with CoO CEs, which deliver a short circuit current density (J sc ) of 20.42 mA/cm 2 , open circuit voltage (V oc ) of 0.655 V and fill factor (FF) of 0.45. Research so far has shown that metal oxide (e.g. CoO) has many excellent properties, such as good electrical conductivity , outstanding catalytic activity , relatively small charge transfer resistance , large surface area and cost-effective, so it is very promising to be a CE material for QDSSCs.