The promising photo anode of graphene/zinc titanium mixed metal oxides for the CdS quantum dot-sensitized solar cell

Abstract In this study, the graphene sheets produced by supercritical CO 2 exfoliation of graphite were used to improve the photovoltaic performance of the CdS quantum dot-sensitized solar cells (QDSSCs). The zinc titanium mixed metal oxides (MMO) based on layered double hydroxide (LDH) precursor and the graphene/MMO hybrid materials were used as photoanodes of the CdS QDSSCs, respectively. The presence of graphene in the photoanodes was confirmed by Raman spectroscopy, X-ray diffraction (XRD) and Energy-dispersive X-ray spectroscopy (EDS). The influence of graphene concentration on the performance of CdS QDSSCs was studied by electrochemical method. The addition of graphene enhanced QDs adsorption properties and lowered internal resistance, so the QDSSCs displayed higher power conversion efficiency (PCE). Accordingly, the highest PCE of the QDSSCs based on graphene/Zn-Ti MMO photoanode reached 0.44% and increased 37.5% in compared with that based on plain Zn-Ti MMO working electrodes.