Density-functional based determination of intermolecular charge transfer properties for large-scale morphologies.
Björn Baumeier1, James Kirkpatrick, Denis Andrienko
1Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany. baumeier@mpip-mainz.mpg.de
Physical Chemistry Chemical Physics : PCCP
|August 7, 2010
Summary
Accurately calculating charge transport requires understanding electron hopping. This study optimizes density-functional theory methods for determining intermolecular transfer integrals, crucial for organic conductor simulations.
Area of Science:
- Computational Chemistry
- Materials Science
- Organic Electronics
Background:
- Charge transport in organic conductors involves tunneling and molecular ordering.
- Electron and hole mobility depend on intermolecular hopping rates.
- Marcus theory uses transfer integrals and on-site energies to calculate hopping rates.
Purpose of the Study:
- To computationally assess density-functional theory (DFT) methods for determining intermolecular transfer integrals.
- To establish an optimal strategy for simulating charge transport in organic morphologies.
Main Methods:
- Utilizing quantum-chemistry calculations to obtain transfer integrals via a projective approach.
- Calculating the expectation value of a dimer Fock operator with frontier orbitals of neighboring monomers.
- Investigating tris(8-hydroxyquinolinato)aluminium (Alq(3)) as a model system.
Main Results:
- Examined the impact of basis sets, exchange-correlation functionals, and convergence criteria on transfer integral calculations.
- Compared results to identify the most accurate and efficient computational parameters.
- Demonstrated a projective approach for deriving transfer integrals from quantum-chemical calculations.
Conclusions:
- Optimized DFT-based strategies are essential for accurate charge transport simulations in organic materials.
- The projective approach provides a reliable method for calculating intermolecular transfer integrals.
- This work guides future simulations of charge transport in complex organic morphologies.
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