In our present work, the power conversion efficiency of our solar cells remains too low for use in practical applications. c-Met inhibitor The rather poor fill factor is considered to be the main factor limiting the energy conversion efficiency. This low fill factor may be ascribed to the lower hole recovery rate of the polysulfide electrolyte, which leads to a higher probability for charge recombination. To improve the efficiency of these CdS/TiO2 nano-branched quantum dot-sensitized solar cells, a new hole transport medium must be developed, one with suitable redox potential and low
electron recombination at the semiconductor-electrolyte interface. Counter electrodes have also been reported to be another important factor influencing the energy conversion efficiency. Recently, a number of novel materials have been examined
and tested find more as counter electrode materials; these studies prove the influence of various counter electrode materials on the fill factors of solar devices [27–29]. In addition, selleck chemicals graphene with outstanding, transparent conducting properties has been explored as an efficient constituent for solar cell applications [30–32]. Further studies will be conducted to optimize the nanostructures and counter electrode materials to improve the performance of our solar cells. Conclusion In this study, large-area nano-branched TiO2 nanorod arrays were grown on fluorine-doped tin oxide glass by a low-cost two-step hydrothermal method. The resultant nanostructures consisted of single-crystalline nanorod trunks and a large number of short TiO2 nanobranches,
which is an effective structure for the deposition of CdS quantum dots. CdS quantum dots were deposited on the nano-branched TiO2 nanorod arrays by a successive ROS1 ionic layer adsorption and reaction method to form an effective photoanode for quantum dot-sensitized solar cells. As the length of nanobranches increased, the conversion efficiency varied respectively. An optimal efficiency of 0.95% was recorded in solar cells based on TiO2 nanorod arrays with optimized nanobranches, indicating an increase of 138% compared to those based on bare TiO2 nanorod arrays. In this aspect, the nano-branched TiO2 arrays on FTO turned out to be more desirable than bare nanorod arrays for the applications of quantum dot-sensitized solar cells.