Abstract

Molecular materials in electronic devices, such as Dye Sensitized Solar Cells (DSSC) or photocatalytic systems for water-splitting, are 2D self assembled monolayers. This implies that intermolecular forces control the architecture, hence the properties, of these systems. Since this phenomenon is difficult to characterize experimentally, there is a demand for simulations to assist the design of electronic devices. However, it is challenging for two reasons. First, it requires precise calculations to capture the effect of the weak intermolecular forces among the covalent interactions which bind the atoms together. Second, relatively big systems are needed (at least a pair of molecules) within which a charge (excess electron) is locally distributed.

In this talk, I am going to present charge constrained DFT (CDFT) calculations on electron transfer systems. CDFT overcome conventional DFT by providing a means to calculate the electronic structure of a pair of charged molecules. The focus is going to be on quantifying electrostatic interactions as a function of the intermolecular separation. This allows me to calculate more accurately the reorganization energy of charge transfer and link the kinetics of charge transport to the structure of a given molecular monolayer.