Simple phenylene-bridged D-π-A type photosensitizers for DSSC application: Synthesis, optical, electrochemical and theoretical studies

Authors

• Kavya S. Keremane a and Airody Vasudeva Adhikari a,b * a Organic Materials Laboratory, Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Mangalore-575025, India
• Airody Vasudeva Adhikari a,b,* b Yenepoya Research Centre, Yenepoya deemed to be University, Deralakatte, Mangalore-575018, India

Abstract

Herein, we report the design and synthesis of two new phenylene-bridged D-π-A configured organic molecules N_1-2 carrying two different anchors and the same donor unit, as potential sensitizers for DSSC application. In the new design, a simple O-alkyl substituted phenyl group acts as a donor scaffold, cyanovinylene, and phenylene systems serve as π-spacers, while cyanoacetic acid and barbituric acid units function as electron acceptor/anchoring moieties. The current work also highlights their structural, photophysical, electrochemical, and theoretical investigations, including evaluation of their structure-property relationships. The optical results revealed that chromophores N_1-2 display λ_abs and λ_emi in the range of 400-420 nm and 550-570 nm, respectively, with a bandgap in the order, 2.51-2.59 eV. Their quantum chemical simulations have provided an insight into the predictions of their structural, molecular, electronic, and optical parameters. Further, the results showcased that the dyes possess all the pre-requisites to act as sensitizers in dye-sensitized solar cells (DSSCs). Conclusively, the study furnishes a deeper understanding of the intricacies involved in the structural modification of phenylene-based dyes for achieving better performance in DSSCs.