Synthesis, characterization and electrochemical impedance study of CdS quantum dot-sensitized solar cell with reduced graphene oxide/TiO2 composite photoanode

Quantum dots and reduced graphene oxide (rGO) play an important role in the performance of the third-generation solar cell. In this work, the performance of quantum dot-sensitized solar cell (QDSSC) with rGO/TiO2 composite photoanode is presented. Mixing of rGO was performed with a facile preparation technique by varying the ratio of rGO (0.1-1.0 wt%) to TiO2. The prepared electrode samples were characterized in order to understand the effect of rGO to the surface morphology, chemical composition and electron lifetime effect. It was observed that the addition of rGO increased the efficiency of QDSSC with maximum efficiency observed for sample having 0.5 wt% of rGO-added TiO2 electrodes. However, more rGO content did not contribute to the improved performance due to increased charge recombination rate. The internal resistance and electron lifetime of the samples are further discussed in this work.