Investigating the potential compatibility of various rhodamine derivatives in dye-sensitized solar cells using an experimental and computational approach

Abstract

Rhodamine derivative based dyes like Rhodamine 6G (R6G), Rhodamine B (RB), Rhodamine 123 (R123), Rhodamine B Isothiocyanate (RB-iso), Sulfo Rhodamine B sodium salt (RB-sulfo) were investigated through density functional theory (DFT) and time-dependent DFT (TD-DFT) for their potential suitability as sensitizers in dye-sensitized solar cells (DSSCs). Out of five dyes, the photovoltaic properties of the three dyes (viz. R123, RB, and RB-sulfo) were investigated experimentally. UV–vis absorption studies were performed to investigate the optical properties of dyes and dye adsorbed onto TiO<inf>2</inf> surface. DSSC made with RB dye exhibited notably better power conversion efficiency (η) of 0.15% with short-circuit photocurrent density (J<inf>SC</inf>) of 0.66 mA cm−2, open-circuit photovoltage (V<inf>OC</inf>) of 0.426 V and fill factor (FF) of 0.54, as compared with other two dyes (RB-sulfo and R123). Findings suggest that RB dye is the most effective sensitizer among other Rhodamine derivative dyes tested as sensitizers in DSSCs. A higher molar extinction coefficient, broad light absorption range, and strong adsorption onto the TiO<inf>2</inf> surface make it a better choice for enhancing the performance of DSSCs. These characteristics enable RB to achieve a higher overall power conversion efficiency than other Rhodamine derivatives. © 2025 Elsevier B.V.