Optimization of Multiple Electron Donor and Acceptor in Carbazole-Triphenylamine-Based Molecules for Application of Dye-Sensitized Solar Cells

Abstract

Organic dyes have been synthesized which containing multiple electron donors (carbazole) and electron acceptors (rhodaniline-3-acetic acid) on triphenylamine (TPA). Photophysical, electrochemical, and theoretical computational methods have categorized these compounds. Nanocrystalline TiO2-based dye-sensitized solar cells (DSSCs) are fabricated using these dye molecules as light-harvesting sensitizers. The overall efficiency of sensitized cells is high (4.64%) as compared to a cis-di(thiocyanato)-bis(2,2′-bipyridyl)-4,4′-dicarboxylate ruthenium(II) (N3 dye)-sensitized device (7.83%) fabricated and measured under the same conditions. Both electron donor (carbazole) and acceptor (rhodaniline-3-acetic acid) play a key role in the increased efficiency. One carbazole and two rhodaniline-3-acetic acid-based dye appears to help convey the charge transfer from the excited dye molecules to the conduction band of TiO2, leading to a higher efficiency of the assembled devices using such a dye. Electrochemical impedanc...