Electronic and Optical Properties of Dye-Sensitized TiO2 Interfaces

Dye-sensitized solar cells (DSCs) represent a promising approach to the direct conversion of sunlight to electrical energy at low cost and high efficiency. DSCs are based on a film of anatase TiO2 nanoparticles covered by adsorbed molecular dyes and immersed in a liquid redox electrolyte. Upon photoexcitation of the chemisorbed dye, electrons are injected into the TiO2 conduction band and can travel across the nanostructured film to reach the counter-electrode, while the oxidized dye is regenerated by the redox electrolyte. In this review we present a summary of recent computational studies of the electronic and optical properties of dye-sensitized TiO2 interfaces, with the aim of providing the basic understanding of the operation principles of DSCs and establishing the conceptual basis for their design and optimization.