Cu2-xS nanocrystals prepared by solvothermal method for highly efficient quantum dot sensitised solar cells

Copper chalcogenide nanostructures such as Cu2-xS have been widely used in quantum dot sensitised solar cells (QDSCs) as counter electrode (CE). Owing to larger surface area and higher catalytic activity, the introduction of the nanostructured Cu2-xS CE is regarded as an efficient approach to improve the performance of QDSCs. Here, we report on a Cu2-xS nanostructured CE for QDSCs. The Cu2-xS nanocrystals with the size of ∼50 nm are prepared by solvothermal method at 160°C for 120 minutes. Such nanostructured CE shows better catalytic activity and charge transfer, larger specific surface area and higher power conversion efficiency (PCE) than those of the common Cu2-xS CE prepared by grass foil. In addition, the charge recombination in QDSCs can be reduced by the nanostructured CE. As a result, one of the best PCE of QDSC with the nanostructured Cu2-xS CE is up to 4.52%. © 2016 Inderscience Enterprises Ltd.