Bio and non-bio materials-based quasi-solid state electrolytes in DSSC: A review

Dye-sensitized solar cells (DSSCs) are more attractive than silicon solar cells due to their low dependency on light intensity so that they can perform both indoor and outdoor with low-level lightings. DSSC's global revenue exceeded 16 million USD in 2014 for emerging portable charging, solar bags, and wireless keyboards. However, on-grid DSSC modules are still under R&D for massive commercialization to improve their long-term stability and safety issues due to the liquid electrolyte leakage. Therefore, quasi-solid-state electrolytes (QSE) have been proposed as a novel alternative to overcome the limitations stated above since 2001. Here, we deliver a short outline of the QSE properties, which are linked with the performance of DSSC in terms of different types of QSE structures: gel, hydrogel, and aerogel. Furthermore, these QSE structures are classified under bio and non-bio materials. Finally, the impact, outlook, and future prospects of QSE-DSSC are included as a conclusion in this review.