Newly designed triazatruxene-based dye-sensitized solar cells containing different benzothiazine π-linkers: Geometric, optoelectronic, charge transfer properties, and cyanoacrylic acid versus benzoic acid

In this work, six new organic (D-pi-A) dyes based on triazatruxene have been designed by modifying the pi linkers groups and the anchor unit of the reference dye R. Their structural, electronic, frontier molecular orbital, chemical reactivity, and photovoltaic have been studied using DFT (density functional theory) at B3LYP/6-31G (d,p). Furthermore, the TD-DFT (time-dependent DFT) at TD-BHandH/6-31G (d,p) level method was chosen to calculate the optical characteristics of the investigated dyes in the solvent CH2Cl2. Molecular properties such as geometric parameters, optoelectronic properties, frontier molecular orbitals, natural bonding orbitals, the partial density of states analysis, electrostatic surface potential, absorption spectra, and electron accepting and donating parameters were assessed to predict proper candidates for the DSSC device. The studied dyes not only show significant lambda max in the range of 500-650 nm, with a band gap in the range of 1.64-1.98 eV, lower lambda tot, but also high light capture efficiency and significant intramolecular charge transfer properties compared to the reference dye (R). Notably, dyes with C(CH3)2 and Si(CH3)2 exhibit the best performance among the designed dyes.

Automated summary

Six new organic (D-pi-A) dyes based on triazatruxene were designed and studied by modifying the pi linkers groups and the anchor unit. Their structural, electronic, and photovoltaic properties were characterized using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The dyes with C(CH3)2 and Si(CH3)2 groups exhibited the best performance, showing lower band gap, higher light capture efficiency, and significant intramolecular charge transfer compared to the reference dye (R).