Dye-sensitized solar cells: Fundamentals, recent progress, and Optoelectrical properties improvement strategies

The better optical and electrical properties provide successful dye-sensitized solar cells (DSSCs) only when the energy alignment between the different materials is matched. When a dye absorbs sufficient light, a device generates electron-hole pairs, flows electrons at one end, and regenerates the dye at the other end. For optoelectrical property enhancement, better interactions between materials such as metal oxide semiconductor/ dye (better anchoring molecules), semiconductor/dye/electrolyte (conductive, non-volatile, and stable electrolyte), and electrolyte/CE (high conductivity CE) are required. This review briefly describes the working mechanism of DSSC and the enhancement of optical and electrical properties by incorporating different materials used in various components. The factors include sintering temperature, illumination intensity, extracting solvent for dye, thin film coating methods, doping, composite ratio in semiconductors, CE, and variable additives used in electrolytes. In addition, the pH of the medium, crystallinity, morphology, co-sensitization of dye, and major pigments and anchoring groups in dye in terms of comparative solar parameters and other optical and electrical properties at different interfaces are included. It also provides the comparative performance of several solar cells by incorporating novel materials in semiconductors, dyes, electrolytes, and CE, which may have the potential for successful DSSC in the future. Finally, based on the available data from other researchers, a comparative study between natural and chemically synthesized dyes in terms of solar parameters has been discussed in the manuscript.