New Carbazole-Based Organic Dyes with Various Acceptors for Dye-Sensitized Solar Cells: Synthesis, Characterization, DSSCs Fabrications and DFT Study

Abstract

The molecular configuration, synthesis and characterization of (E)-3-(6-bromo-9-phenyl-9H-carbazol- 3-yl)acrylic acid (BPA), (E)-3-(6-bromo-9-phenyl-9H-carbazol-3-yl)-2-cyanoacrylic acid (BPCA) and (E)-N′-((6-bromo-9-phenyl-9H-carbazol-3-yl)methylene)-2-cyanoacetohydrazide (BPCH) configured D-π-A sensitizers and the sensitizers are used in DSSCs. Dye molecules are described by FT-IR, NMR and UV-Vis analysis. The study shows that the non-planar structure of BPA, BPCA and BPCH can effectively slow down the aggregation and conjugation of the dye. Computed vibrational modes are compared with observed bands. The Frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) have also been calculated using DFT-B3LYP/6-311++G(d,p) basis set. Physical-chemical parameters have also been analyzed using density functional theory. The most excellent DSSC performance in photovoltaic characterization is demonstrated by the dye molecules.