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

Abstract

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 Cu2S 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 (Jsc) of 20.42 mA/cm2, open circuit voltage (Voc) 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.