# Luminescence Materials for Dye-Sensitized Solar Cells: Advances and Directions
## 6 Conclusions  
Luminescent materials present a promising and innovative avenue for enhancing dye-sensitized solar cells (DSSCs). Ongoing research continues to advance the development and integration of these materials, offering significant potential for improving DSSC efficiency, commercialization and deployment. DSSCs offer a clean and sustainable method for generating power without causing environmental pollution. In these systems, the dye sensitiizer absorbs photons, while TiO\({}_{2}\) facilitates charge carrier transport to the external circuit. DSSCs have gathered considerable attention due to their low cost and compatibility with various materials. However, their power conversion efficiency remains lower than that of traditional silicon-based solar cells. In this review, we focused our insights on the impact of luminescent materials, a vital component that greatly influences both the photovoltaic power conversion performance and the long term durability of the DSSCs.  
We identified luminescent materials as down-conversion, up-conversion and quantum dots. These materials attracted a significant research interest of over 200,000 publications, according to the \"Web of Science\" data. They have the ability to extend the absorption spectrum beyond the visible region of the typical dye sensitizer to enhance the performance of the DSSCs. The key challenges of these materials include stability under operational conditions and energy transfer efficiency.  
Improving the energy transfer efficiency between luminescent materials and the dye molecules is one of the recommendations to mitigate these challenges. A better understanding of the spectral alignment between these components is crucial to enhance energy transfer efficiency. Spectral modelling and spectroscopic techniques could provide valuable insights into these mechanisms to foster the design of more efficient DSSCs.  
Also, improving the stability of luminescent materials under operational conditions is vital, as long-term durability is crucial for the viability of DSSCs. Future research should prioritize the development materials that resist photo-degradation. Therefore, techniques such as encapsulation that shields other components of DSSCs from UV light and preventing photo-degradation is vital. Also, thin layers of alumina (Al\({}_{2}\)O\({}_{3}\)) can be incorporated on the surface of the TiO\({}_{2}\) luminescent layer to enhance its durability and resistance to photo-degradation. The addition of an antioxidant such as Butylated Hydroxytoluene (BHT) and Butylated Hydroxyanisole (BHA), which can be used to protect the dye and electrolyte from oxidative degradation, can also stabilize the electrolyte and the dye in DSSCs.  
Further, developing multifunctional luminescent materials such as the Boron-Dipyrro-methene dyes that can serve dual purposes such as light absorption and charge transport could streamline DSSC design and enhance performance. This could minimize the number of interfaces within the cell, reducing recombination losses and enhancing longevity and efficiency.  
Conceptualization, E.H.O. and N.L.L.; validation, E.H.O., N.L.L. and P.M.; formal analysis, E.H.O. and N.L.L.; data curation, E.H.O.; writing--original draft preparation, E.H.O.; writing--review and editing, E.H.O. and N.L.L.; visualization, E.H.O.; supervision, N.L.L. and P.M. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the Research Niche Area (RNA), Renewable Energy Wind in Govan Mbeki Research and Development Centre (GMRDC), University of Fort Hare, Alice, South Africa.  
Not applicable.  
No new data were created or analyzed in this study.  
We acknowledge the assistance of the SAMRC Microbial Water Quality Monitoring Centre of the University of Fort Hare, Alice, South Africa.  
The authors declare no conflicts of interest.