The Role of the p Linker in Donor-p-Acceptor Organic Dyes for High-Performance Sensitized Solar Cells

The key elements arising from different linkers between donor (D) and acceptor (A) fragments in DpA organic dyes are computationally studied. Taking triarylamine and the cyanoacrylic acid fragments as donor and acceptor units, respectively, the role of the different separators is computationally explored by means of optimized geometries, frontier molecular orbitals, static polarizabilities and hyperpolarizabilities, excitation energies to the lowest excited singlet, the charge-transfer character of the transition, and simulated absorption spectra. The results are compared to two closely related sets of linkers. Electronic-structure calculations on the studied organic dyes are performed with the CIS(D) wave function based method and time-dependent density functional theory (?B97, ?B97X, and ?PBEh functionals). Solvation effects are introduced with the polarizable continuum model (PCM).