Electron Attachment to Dye-Sensitized Solar Cell Components: Rhodanine and Rhodanine-3-acetic Acid

Abstract

The energies of electron attachment associated with temporary occupation of π* and σ* virtual orbitals of the pentaheterocyclic rhodanine molecule are measured in the gas phase with electron transmission spectroscopy. The corresponding orbital energies of the neutral molecule, supplied by B3LYP/6-31G(d) calculations and scaled using an empirically calibrated linear equation, are compared with the experimental vertical attachment energies. The same computational procedure is applied to rhodanine-3-acetic acid, proposed as a possible component of dye-sensitized solar cells. In addition, the (positive) vertical and adiabatic electron affinities are evaluated at the B3LYP/6-31+G(d) level. The calculations also indicate a thermodynamic tendency toward dissociation of the ring H2C−S bond of the molecular anion. Dissociative electron attachment spectroscopy is used to measure the total anion current, as a function of the incident electron energy, and detect with a mass filter the negative fragments generated thr...