Interface effect of graphene-TiO_2 photoanode with CuO nanorod counter electrode on solar conversion efficiency and enhanced external quantum efficiency

摘要

In this study, graphene-TiO2 nanostructures and CuO nanorods were produced on FTO (F:SnO2) substrates using the cost effective hydrothermal growth method. The interface effects of the graphene-TiO2 nanostructures were examined to compare with pure TiO2 photoanode in respect to solar cell efficiency. Graphene-TiO2 was shown as a perfect alternative for the standard F:SnO2 (FTO)/TiO2 working electrodes in dye-sensitized solar cells due to its higher electro-optic activity, surface area and good charge transport characteristics. Furthermore, CuO nanorods were also investigated as efficient counter electrodes (CEs) to be used in place of the conventional and costly platinum (Pt) CEs. By utilizing graphene-TiO2 photoanode and CuO nanorod based CEs, hybrid solar cells with photovoltaic efficiency of 6.18% under AM 1.5G solar radiation were produced. According to the external quantum efficiency (EQE) of the hybrid solar cell agreement with the J-V measurements, the device based on the hybrid CuO CE exhibited higher EQE. EQE was improved by 30% compared to the Pt CE due to the higher Jsc, Voc and the fill factor of the hybrid devices.