Recent advances in quantum dot-sensitized solar cells: insights into photoanodes, sensitizers, electrolytes and counter electrodes

Quantum dot-sensitized solar cells (QDSCs), as promising candidates for cost-effective photoelectrochemical solar cells, have attracted much attention due to their characteristic properties such as processability at low cost, feasibility to control light absorption spectrum in a wide region, and possibility of multiple electron generation with a theoretical conversion efficiency up to 44%. QDSCs have analogous structures to dye-sensitized solar cells typically consisting of semiconductor photoanodes sensitized with quantum dots (QDs), redox electrolytes, and counter electrodes (CEs). Much effort has been dedicated to optimizing each component of QDSCs for higher device performance. In this review, recent advances of photoanodes with various architectures, QDs with tunable band gaps, electrolytes in liquid, quasi-solid or solid state, and CEs with great electrocatalytic activity for QDSCs will be highlighted. We aim to elaborate the rational strategies in material design for QDSC applications. Finally, the conclusion and future prospects emphasize the key developments and remaining challenges for QDSCs.