Regensburg 2016 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 46: Organic Semiconductors
HL 46.6: Talk
Wednesday, March 9, 2016, 11:15–11:30, H13
Strain and Pressure Dependent Electronic Properties of Polyacetylene — •Franz Knuth1, Christian Carbogno1, Volker Blum2, and Matthias Scheffler1 — 1Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany — 2MEMS Department, Duke University, Durham, NC 27708, USA
Strain, stress, and pressure can influence the electronic properties of organic semiconductors [1]. In this contribution, we present the changes of electronic and transport properties for crystalline trans-polyacetylene under strain and hydrostatic pressure in the framework of density-functional theory. We critically discuss the role of approximations in the exchange-correlation functional and show that the fraction of exact exchange included in the calculations with hybrid functionals is non-trivial to choose and essential for the correct description of polyacetylene. The pressure studies are performed with the help of the analytical strain derivatives (stress tensor) including the contributions coming from van-der-Waals corrections and exact exchange [2]. Our calculations also reveal that the electronic band structure and gap of polyacetylene are not only determined by the dimerization of the carbon chain but are at least as much influenced by interchain interactions.
[1] J. H. Kim, S. Seo, and H. H. Lee, Appl. Phys. Lett. 90, 143521 (2007); G. Giri et al., Nature. 480, 504 (2011)
[2] F. Knuth et al., Comp. Phys. Comm. 190, 33 (2015)