Accurate method for obtaining band gaps in conducting polymers using a DFT/hybrid approach
Date
1998Source Title
Journal of Physical Chemistry A
Print ISSN
1089-5639
Publisher
American Chemical Society
Volume
102
Issue
15
Pages
2572 - 2578
Language
English
Type
ArticleItem Usage Stats
228
views
views
322
downloads
downloads
Abstract
DFT calculations on a series of oligomers have been used to estimate band gaps, ionization potentials, electron affinities, and bandwidths for polyacetylene, polythiophene, polypyrrole, polythiazole, and a thiophene - thiazole copolymer. Using a slightly modified hybrid functional, we obtain band gaps within 0.1 eV of experimental solid-state values Calculated bond lengths and bond angles for the central ring of sexithiophene differ by less than 0.026 Å and 0.7° from those of the sexithiopnene crystal structure. IPs and EAs are overestimated by up to 0.77 eV compared to experimental bulk values. Extrapolated bandwidths agree reasonably well with bandwidths from band structure calculations.
Keywords
Approximation theoryChemical bonds
Copolymers
Crystal structure
Electron energy levels
Energy gap
Ionization
Organic polymers
Polyacetylenes
Probability density function
Band gap
Electron affinities
Ionization potentials
Polypyrrole
Polythiophene
Band structure