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HL: Fachverband Halbleiterphysik
HL 62: Electronic-Structure Theory: New Concepts and Developments in Density Functional Theory and Beyond - V
HL 62.7: Talk
Wednesday, March 22, 2017, 16:30–16:45, GER 38
Calculation of charge transfer integrals using constrained-DFT — •Tobias Lettmann and Nikos Doltsinis — Institut für Festkörpertheorie, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Deutschland
For the investigation of charge transport properties of organic semiconductor materials, the fast and accurate calculation of charge transfer integrals (or transition matrix elements) is desirable. It has been suggested that the transfer integrals depend on a universal linear function of the corresponding wavefunction overlap, which can then be used to approximate the integral at a reduced computational cost1.
We have calculated transfer integrals for dimers of poly(3-hexylthiophene) (P3HT) and diperylene bisimide (DiPBI), which are used in organic solar cells, in a large variety of intra- and inter-molecular conformations and polymer lengths using a constrained-DFT approach2. Our results show, that there is indeed a universal relation between transfer integral and wavefunction overlap. However this relation is (i) nonlinear for large overlaps and (ii) only holds true if the transfer integral is rescaled by the number of electrons of the respective system.
1 F. Gajdos et al.: J. Chem. Theory Comput., 2014, 10, 4653
2 H. Oberhofer, J. Blumberger: J. Chem. Phys., 2010, 133, 244105