Journal ArticleDOI
Unification of trap-limited electron transport in semiconducting polymers
Herman T. Nicolai,Martijn Kuik,Gert-Jan A. H. Wetzelaer,B. de Boer,Casey M. Campbell,Chad Risko,Jean-Luc Brédas,Jean-Luc Brédas,Paul W. M. Blom +8 more
TLDR
It is observed for this materials class that electron transport is limited by traps that exhibit a gaussian energy distribution in the bandgap, which indicates that the electron traps have a common origin that, it is suggested, is most likely related to hydrated oxygen complexes.Abstract:
Electron transport in semiconducting polymers is usually inferior to hole transport, which is ascribed to charge trapping on isolated defect sites situated within the energy bandgap. However, a general understanding of the origin of these omnipresent charge traps, as well as their energetic position, distribution and concentration, is lacking. Here we investigate electron transport in a wide range of semiconducting polymers by current-voltage measurements of single-carrier devices. We observe for this materials class that electron transport is limited by traps that exhibit a Gaussian energy distribution in the bandgap. Remarkably, the electron-trap distribution is identical for all polymers considered: the number of traps amounts to 3 × 1023 traps per m3 centred at an energy of ∼3.6 eV below the vacuum level, with a typical distribution width of ∼0.1 eV. This indicates that the electron traps have a common origin that, we suggest, is most likely related to hydrated oxygen complexes. A consequence of this finding is that the trap-limited electron current can be predicted for any polymer. © 2012 Macmillan Publishers Limited. All rights reserved.read more
Citations
More filters
Journal ArticleDOI
Organic Optoelectronic Materials: Mechanisms and Applications
TL;DR: The article reviews the current understanding of the physical mechanisms that determine the (opto)electronic properties of high-performance organic materials and highlights the capabilities of various experimental techniques for characterization, summarizes top-of-the-line device performance, and outlines recent trends in the further development of the field.
Journal ArticleDOI
Organic thermoelectric materials for energy harvesting and temperature control
TL;DR: In this article, the authors discuss recent breakthroughs for organic materials with high thermoelectric figures of merit and indicate how these materials may be incorporated into new module designs that take advantage of their mechanical properties.
Journal ArticleDOI
Exciton diffusion in organic semiconductors
TL;DR: In this paper, the authors provide a basic physical description of the exciton diffusion in organic semiconductors and present experimental methods that are used to measure the key parameters of this process.
Journal ArticleDOI
Charge carrier recombination in organic solar cells
TL;DR: In this paper, the authors review the latest on geminate and nongeminate recombination in organic solar cells and discuss the key loss mechanisms in charge carrier recombination, which is one of the most promising alternative energy sources because of their ease of processing and their potential to be produced using large scale techniques such as roll-to-roll, newspaper style, coating.
Journal ArticleDOI
Controlling Molecular Doping in Organic Semiconductors
Ian E. Jacobs,Adam J. Moulé +1 more
TL;DR: Recent breakthroughs in molecular doping of organic semiconductors suggest a role for molecular doping not only in device function but also in fabrication-applications beyond those directly analogous to inorganic doping.
References
More filters
Book
CRC Handbook of Chemistry and Physics
TL;DR: CRC handbook of chemistry and physics, CRC Handbook of Chemistry and Physics, CRC handbook as discussed by the authors, CRC Handbook for Chemistry and Physiology, CRC Handbook for Physics,
Journal ArticleDOI
Semiempirical GGA-type density functional constructed with a long-range dispersion correction.
TL;DR: A new density functional of the generalized gradient approximation (GGA) type for general chemistry applications termed B97‐D is proposed, based on Becke's power‐series ansatz from 1997, and is explicitly parameterized by including damped atom‐pairwise dispersion corrections of the form C6 · R−6.
Journal ArticleDOI
COSMO : a new approach to dielectric screening in solvents with explicit expressions for the screening energy and its gradient
Andreas Klamt,Gerrit Schüürmann +1 more
TL;DR: In this paper, an algorithm for the accurate calculation of dielectric screening effects in solvents is presented, which leads to rather simple expressions for the screening energy and its analytic gradient with respect to the solute coordinates.
Journal ArticleDOI
Quantum Calculation of Molecular Energies and Energy Gradients in Solution by a Conductor Solvent Model
Vincenzo Barone,Maurizio Cossi +1 more
TL;DR: In this paper, a new implementation of the conductor-like screening solvation model (COSMO) in the GAUSSIAN94 package is presented, which allows Hartree−Fock (HF), density functional (DF) and post-HF energy, and HF and DF gradient calculations: the cavities are modeled on the molecular shape, using recently optimized parameters, and both electrostatic and nonelectrostatic contributions to energies and gradients are considered.
Journal ArticleDOI
Energies, structures, and electronic properties of molecules in solution with the C-PCM solvation model.
TL;DR: The conductor‐like solvation model, as developed in the framework of the polarizable continuum model (PCM), has been reformulated and newly implemented in order to compute energies, geometric structures, harmonic frequencies, and electronic properties in solution for any chemical system that can be studied in vacuo.