First-principles GW calculations for fullerenes, porphyrins, phtalocyanine, and other molecules of interest for organic photovoltaic applications - Condensed Matter > Materials ScienceReport as inadecuate




First-principles GW calculations for fullerenes, porphyrins, phtalocyanine, and other molecules of interest for organic photovoltaic applications - Condensed Matter > Materials Science - Download this document for free, or read online. Document in PDF available to download.

Abstract: We evaluate the performances of ab initio GW calculations for the ionizationenergies and HOMO-LUMO gaps of thirteen gas phase molecules of interest fororganic electronic and photovoltaic applications, including the C60 fullerene,pentacene, free-base porphyrins and phtalocyanine, PTCDA, and standard monomerssuch as thiophene, fluorene, benzothiazole or thiadiazole. Standard G0W0calculations, that is starting from eigenstates obtained with local orsemilocal functionals, significantly improve the ionization energy and band gapas compared to density functional theory Kohn-Sham results, but the calculatedquasiparticle values remain too small as a result of overscreening. Startingfrom Hartree-Fock-like eigenvalues provides much better results and isequivalent to performing self-consistency on the eigenvalues, with a resultingaccuracy of 2~4% as compared to experiment. Our calculations are based on anefficient gaussian-basis implementation of GW with explicit treatment of thedynamical screening through contour deformation techniques.



Author: Xavier Blase, Claudio Attaccalite, Valerio Olevano

Source: https://arxiv.org/







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