Modelling of the charge carrier mobility in disordered linear polymer materials

0472995 - ÚMCH 2018 RIV GB eng J - Journal Article
Toman, Petr - Menšík, Miroslav - Bartkowiak, W. - Pfleger, Jiří
Modelling of the charge carrier mobility in disordered linear polymer materials.
Physical Chemistry Chemical Physics. Roč. 19, č. 11 (2017), s. 7760-7771. ISSN 1463-9076. E-ISSN 1463-9084
R&D Projects: GA ČR(CZ) GA15-05095S
Grant - others:AV ČR(CZ) M200501204
Program: M
Institutional support: RVO:61389013
Keywords : charge carrier mobility * conjugated polymer * charge transport modelling
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 3.906, year: 2017

We introduced a molecular-scale description of disordered on-chain charge carrier states into a theoretical model of the charge carrier transport in polymer semiconductors. The presented model combines the quantum mechanical approach with a semi-classical solution of the inter-chain charge hopping. Our model takes into account the significant local anisotropy of the charge carrier mobility present in linear conjugated polymers. Contrary to the models based on the effective medium approximation, our approach allowed avoiding artefacts in the calculated concentration dependence of the mobility originated in its problematic configurational averaging. Monte Carlo numerical calculations show that, depending on the degree of the energetic and structural disorder, the charge carrier mobility increases significantly with increasing charge concentration due to trap filling. At high charge carrier concentrations, the effect of the energetic disorder disappears and the mobility decreases slightly due to the lower density of unoccupied states available for the hopping transport. It could explain the experimentally observed mobility degradation in organic field-effect transistors at high gate voltage.
Permanent Link: http://hdl.handle.net/11104/0271122