Nanofillers in the electrolytes of dye-sensitized solar cells – A short review

Dye-sensitized solar cells (DSSCs) are a promising alternative for conventional silicon solar cells in terms of high energy conversion efficiency and low production cost. However, liquid-state DSSCs exhibit poor long-term stability since volatile liquid electrolytes are utilized. An effective, simple approach to improving the stability as well as the photovoltaic performance of DSSCs, is by replacing liquid electrolytes with nanocomposite electrolytes. This paper reviews various state-of-the-art nanocomposite electrolytes in view of their physical and electrochemical properties for application in DSSCs. This review mainly focuses on various types of inorganic materials such as clays, metal oxides, metal nitrides, metal carbides, metal sulfides and carbonaceous materials as nanofillers (NFs) in nanocomposite electrolytes. The influence of the sizes, shapes, and surface functional groups of these NFs on the properties of the nanocomposite electrolytes are described. The working mechanism of the DSSCs based on the interactions of these NFs with the electrolytes are presented. The long-term stability of the DSSCs using nanocomposite electrolytes at different temperatures is reviewed. In addition, the methods used to evaluate the mechanical, electrochemical, thermal and long-term stability of the electrodes, electrolytes, and DSSCs are summarized.