Vibrational and Electronic Spectra of Natural Dyes Constituents for Solar Cell Application: DFT and TDDFT Study

Abstract

Selected constituents of natural dyes, phenol, 1,2-benzoquinone, 1,4-benzoquinone, 1,4-naphthoquinone, and 9,10-anthraquinone have been studied theoretically using the density functional theory and time-dependent density functional theory. The vibrational and electronic spectra have been computed with 6-311++G(d,p) basis set. It was found that 1,2-benzoquinone, 1,4-naphthoquinone, and 9,10-anthraquinone may satisfy some criteria to become photosensitizer in DSSCs; the absorption bands computed for molecules in vacuum appeared at 396, 348, and 326 nm, respectively. When computed for molecules in solutions using the polarized continuum model, the bands were red-shifted: 446 (1,2-benzoquinone in water), 355 (1,4-naphthoquinone in heptane), and 329 nm (9,10-anthraquinone in heptane). Our results have shown that 1,2-benzoquinone among the others would exhibit better photovoltaic properties in terms of light absorption and energy level alignment.