Dresden 2014 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 7: Organic electronics and photovoltaics I (organized by CPP)

HL 7.1: Invited Talk

Monday, March 31, 2014, 09:30–10:00, ZEU 222

Structure-property relations in perylene bisimids: Charge mobility, exiton diffusion and singlet exciton fission — •Ferdinand Grozema — Delft University of Technology, Department of Chemical Engineering, Delft, The Netherlands

Perylene diimides (PDIs) represent a class of materials that is promising for application as the active layer in field effect transistors and as an electron accepting material in organic photovoltaic cells. The electronic properties of PDI-based materials strongly depend on the supramolecular order in the material. Therefore, a thorough understanding of the relation between the electronic properties and the organization on the molecular scale can result in design rules for the synthesis of new π-conjugated organic molecules .

To achieve this we have performed a combined experimental and theoretical study of the electronic properties of a large library of PDI derivatives that differ in the side chains, resulting in subtle differences in the crystal structure. By time-resolved microwave conductivity measurements we show a strong correlation between the supramolecular organization and the charge carrier mobility, with a maximum mobility of 0.41 cm2/Vs. Singlet exciton fission, a process in which a singlet excited state is efficiently converted into two triplets, is also found to be strongly dependent on the supramolecular organization.

This comprehensive study shows that the engineering of the supramolcular organization in PDIs and conjugated molecules in general is viable approach to tailor a variety of electronic properties of such materials over a wide range.