Direct vs. indirect mechanisms for electron injection in DSSC: Catechol and alizarin

In this work, the electronic structure and the optical response of both dyes, free and bound to TiO2 (one of the most common semiconductors used in DSSC) have been analysed and compared using time-dependent density functional theory (TD-DFT) performing calculations both in real time and frequency domains. Results illustrate those characteristic aspects of each sensitizer to follow different electron injection mechanisms.