Computational Investigation of the Influence of π‐Bridge Conjugation Order of Thiophene and Thiazole Units in Triphenylamine Based Dyes in Dye‐Sensitized Solar Cells

Abstract

AbstractIn this study, ten triphenylamine based dyes were investigated by varying the π‐bridge size with a different order of thiophene and thiazole units to understand their potential use in dye‐sensitized solar cells (DSSCs). Geometry optimization, the energy levels and electron density of the highest occupied molecular orbital and the lowest unoccupied molecular orbital, and UV‐visible absorption spectra were calculated using density functional theory (DFT) and time‐dependent DFT (TD‐DFT) methods. The electron injection driving force, dye regeneration driving force, natural bond orbital (NBO) analysis of dye‐(TiO2)8 cluster and dye reorganization energy were calculated to predict the most suitable dyes for DSSC application. Dye 4 ((Z)‐2‐cyano‐3‐(2′‐((E)‐4‐(diphenylamino)styryl)‐[2, 5′‐bithiazol]‐4‐yl)acrylic acid) followed by Dye 6 ((Z)‐2‐cyano‐3‐(5‐(2‐((E)‐4‐(diphenylamino)styryl)thiazol‐5‐yl)thiophen‐3‐yl)acrylic acid) having two linker moieties were identified as the potential candidates.