Theoretical insight into electronic and photoelectrochemical properties of orcein dyes relevant to dye-sensitized solar cells

摘要

Electronic and photoelectrochemical properties of the natural dyes α-, β-, and γ-orceins, related to the performance of dye-sensitized solar cells, were studied by density functional theory (DFT) and time-dependent TDDFT at the B3LYP/6-31+G(d) level. The integral equation formalism-polarizable continuum model (IE-FPCM) was employed for solvation effect. The computational results show that all eight orcein dyes can be suggested for use as a photosensitizer in DSSC due to their matching electronic energy LUMO and HOMO levels for the conduction band edge of TiO2 and the oxidation potential of I~-/I3~- electrolyte, respectively. The P-AOI and γ-AIO possess the best computed parameters related to photochemical properties such as excited state oxidation potential, electron injection force, and photoinduced electron transfer and also open-circuit voltage among the other dyes.