Charge carrier mobilities in organic semiconductor crystals based on the spectral overlap.

The prediction of substance-related charge-transport properties is important for the tayloring of new materials for organic devices, such as organic solar cells. Assuming a hopping process, the Marcus theory is frequently used to model charge transport. Here another approach, which is already widely used for exciton transport, is adapted to charge transport.

Identification of ultrafast relaxation processes as a major reason for inefficient exciton diffusion in perylene-based organic semiconductors.

The exciton diffusion length (LD) is a key parameter for the efficiency of organic optoelectronic devices. Its limitation to the nm length scale causes the need of complex bulk-heterojunction solar cells incorporating difficulties in long-term stability and reproducibility. A comprehensive model providing an atomistic understanding of processes that limit exciton trasport is therefore highly desirable and will be proposed here for perylene-based materials.

Singlet Exciton Diffusion in Organic Crystals Based on Marcus Transfer Rates.

Exciton diffusion is a critical step for energy conversion in optoelectronic devices. This spawns the desire for theoretical approaches that allow for fast but reliable determinations of the material-dependent exciton transport parameters. For this purpose, the Marcus theory, which is widely used in the context of charge transport, is adapted to exciton diffusion.