Electronic transport and quantum localization effects in organic semiconductors
- 7 December 2012
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 86 (24)
- https://doi.org/10.1103/physrevb.86.245201
Abstract
We explore the charge transport mechanism in organic semiconductors based on a model that accounts for the thermal intermolecular disorder at work in pure crystalline compounds, as well as extrinsic sources of disorder that are present in current experimental devices. Starting from the Kubo formula, we describe a theoretical framework that relates the time-dependent quantum dynamics of electrons to the frequency-dependent conductivity. The electron mobility is then calculated through a relaxation time approximation that accounts for quantum localization corrections beyond Boltzmann theory, and allows us to efficiently address the interplay between highly conducting states in the band range and localized states induced by disorder in the band tails. The emergence of a ``transient localization'' phenomenon is shown to be a general feature of organic semiconductors that is compatible with the bandlike temperature dependence of the mobility observed in pure compounds. Carrier trapping by extrinsic disorder causes a crossover to a thermally activated behavior at low temperature, which is progressively suppressed upon increasing the carrier concentration, as is commonly observed in organic field-effect transistors. Our results establish a direct connection between the localization of the electronic states and their conductive properties, formalizing phenomenological considerations that are commonly used in the literature.Keywords
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This publication has 45 references indexed in Scilit:
- Electron-Phonon Coupling in Crystalline Organic Semiconductors: Microscopic Evidence for Nonpolaronic Charge CarriersPhysical Review Letters, 2012
- Band‐Like Electron Transport in Organic Transistors and Implication of the Molecular Structure for Performance OptimizationAdvanced Materials, 2011
- Band Dispersion and Electronic Lifetimes in Crystalline Organic SemiconductorsPhysical Review Letters, 2011
- Solution‐Processable Organic Single Crystals with Bandlike Transport in Field‐Effect TransistorsAdvanced Materials, 2010
- Band-like temperature dependence of mobility in a solution-processed organic semiconductorNature Materials, 2010
- Quantitative analysis of density-dependent transport in tetramethyltetraselenafulvalene single-crystal transistors: Intrinsic properties and trappingPhysical Review B, 2009
- Hall Effect in the Accumulation Layers on the Surface of Organic SemiconductorsPhysical Review Letters, 2005
- Three-dimensional band structure and bandlike mobility in oligoacene single crystals: A theoretical investigationThe Journal of Chemical Physics, 2003
- Theory of electronic transport in molecular crystals. III. Diffusion coefficient incorporating nonlocal linear electron–phonon couplingThe Journal of Chemical Physics, 1985
- Electron-Phonon Interaction in Organic Molecular CrystalsPhysical Review B, 1965