Modelling of the charge carrier mobility in disordered linear polymer materials. Issue 11 (6th March 2017)

• Record Type: Journal Article
• Authors: Toman, Petr; Menšík, Miroslav; Bartkowiak, Wojciech; Pfleger, Jiří
• Is Part Of: Physical chemistry chemical physics. Volume 19:Issue 11(2017)
• Page Start: 7760
• Page End: 7771
• Publication Date: 2017-03-06
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c6cp07789g
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Concentration dependence of the hole mobility in the crystalline and amorphous P3HT calculated for different values of the local energetic disorder σ ε . Abstract : 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.