Boosting DSSC Performance: Co‐Sensitization With Morinda citrifolia ‐Derived Carbon Dots for Enhanced Light Harvesting

ABSTRACT This study explores a novel co‐sensitization architecture utilizing carbon dots (CDs) derived from Morinda citrifolia in combination with the N719 dye to enhance the light‐harvesting efficiency of dye‐sensitized solar cells (DSSCs). The CDs were synthesized through a hydrothermal process using an aqueous extract of Morinda citrifolia fruit juice, resulting in a material with broad optical absorption properties. To investigate their effectiveness in DSSCs, the synthesized CDs were incorporated and used with two different co‐sensitization strategies. In the first approach (DN), the CDs were initially adsorbed onto the photoanode, followed by sensitization with N719 dye. The second configuration (DND) employed a sandwich structure where the photoanode was sequentially sensitized with CDs, N719 dye, and an additional layer of CDs. In this study, TiO 2 was used as the photoanode material, with N719 and CD‐modified N719 acting as sensitizers, Iodolyte HI‐30 as the electrolyte, and Platisol T/sp as the counter electrode. Among the two configurations, the DND structure exhibited the highest power conversion efficiency (PCE) of 5.3%, demonstrating the potential of this co‐sensitization approach. The significant enhancement in DSSC performance highlights the effectiveness of Morinda citrifolia ‐derived carbon dots as a promising, cost‐effective strategy for improving the efficiency of next‐generation DSSCs.