Theory of charge-carrier transport through DNA and other organic crystals

• Applicant: Dr. Karsten Hannewald
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2005 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5452605

• Final Report Year: 2014

Final Report Abstract

Within this project, we have provided a fundamental contribution to the theoretical understanding and first-principles description of charge-carrier transport through DNA-based and other organic crystals. In order to gain insight into the microscopic transport processes in these materials which are relevant for organic electronics, we have utilized and further developed a combined model- Hamiltonian and ab-initio approach for the calculation of their charge-carrier mobilities. In particular, the project has focussed on the influence of the coupling between the electrons and molecular vibrations (phonons) on the charge transport through self-assembled π-stacked guanine, durene, and naphthalene crystals. Thereby, the effects of the relevant scattering mechanisms for the charged particles, the influence of finite temperatures, as well as the relationship between the molecular stacking motif (layered vs. herringbone) and the predominant transport characteristics (1D vs. 2D) have been studied in detail. Apart from the fundamental insight gained concerning electronic transport processes in organic crystals, the results from this project are also relevant for the experimental understanding (and possibly even the design) of organic field-effect transistors.

Publications

• "Ab initio studies of structural, vibrational, and electronic properties of durene crystals and molecules" Phys. Rev. B 75, 195219 (2007)
  F. Ortmann, K. Hannewald, and F. Bechstedt
  
• "Ab initio description and visualization of charge transport in durene crystals" Appl. Phys. Lett. 93, 222105 (2008)
  F. Ortmann, K. Hannewald, and F. Bechstedt
  
• "Electronic properties of durene crystals: Implications for charge transport" Phys. Stat. Sol. B 245, 825 (2008)
  F. Ortmann, K. Hannewald, and F. Bechstedt
  
• "Guanine crystals: A first principles study" J. Phys. Chem. B 112, 1540 (2008)
  F. Ortmann, K. Hannewald, and F. Bechstedt
  
• "Charge transport in guanine-based materials" J. Phys. Chem. B 113, 7367 (2009)
  F. Ortmann, K. Hannewald, and F. Bechstedt
  
• "Theory of charge transport in organic crystals: Beyond Holstein's small-polaron model" Phys. Rev. B 79, 235206 (2009)
  F. Ortmann, F. Bechstedt, and K. Hannewald
  
• "Characteristics of small- and large-polaron motion in organic crystals" J. Phys.: Cond. Matter 22, 465802 (2010)
  F. Ortmann, F. Bechstedt, and K. Hannewald
  
• "Charge transport in organic crystals: Interplay of band transport, hopping, and electron-phonon scattering" New J. Phys. 12, 023011 (2010)
  F. Ortmann, F. Bechstedt, and K. Hannewald
  
• "Charge transport in organic crystals: Theory and modelling" Phys. Stat. Sol. B 248, 511 (2011)
  F. Ortmann, F. Bechstedt, and K. Hannewald