Modeling organic electronic materials: bridging length and time scales

Harrelson, Thomas F.; Moulé, Adam J.; Faller, Roland

doi:10.1080/08927022.2016.1273526

Cited by 9 publications

(8 citation statements)

References 81 publications

(99 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In identifying the difficulty of predicting the interaction between dopants and OSCs, we point out that modeling this system at the molecular scale requires both electronic (usually, density functional theory (DFT)) and structural (usually, molecular dynamics) components and that development of multiscale models combining these levels of theory is at the leading edge of theoretical capabilities . We encourage more research in this area.…”

Section: Fabrication and Morphologymentioning

confidence: 99%

Controlling Molecular Doping in Organic Semiconductors

2017

Self Cite

View full text Add to dashboard Cite

The field of organic electronics thrives on the hope of enabling low-cost, solution-processed electronic devices with mechanical, optoelectronic, and chemical properties not available from inorganic semiconductors. A key to the success of these aspirations is the ability to controllably dope organic semiconductors with high spatial resolution. Here, recent progress in molecular doping of organic semiconductors is summarized, with an emphasis on solution-processed p-type doped polymeric semiconductors. Highlighted topics include how solution-processing techniques can control the distribution, diffusion, and density of dopants within the organic semiconductor, and, in turn, affect the electronic properties of the material. Research in these areas has recently intensified, thanks to advances in chemical synthesis, improved understanding of charged states in organic materials, and a focus on relating fabrication techniques to morphology. Significant disorder in these systems, along with complex interactions between doping and film morphology, is often responsible for charge trapping and low doping efficiency. However, the strong coupling between doping, solubility, and morphology can be harnessed to control crystallinity, create doping gradients, and pattern polymers. These breakthroughs suggest a role for molecular doping not only in device function but also in fabrication-applications beyond those directly analogous to inorganic doping.

show abstract

Section: Fabrication and Morphologymentioning

confidence: 99%

Controlling Molecular Doping in Organic Semiconductors

2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…[24][25][26][27] As described below, in this work we further validate this force field by comparing with experimental densities as a function of temperature. Furthermore, although other all-atom force field models have been developed for molten P3HT, [28][29][30][31] the force field parameters in these models, including backbone dihedral potentials, are developed in a way similar as Huang et al did for the current P3HT model. The resulting dihedral angle distributions and densities for molten P3HT are similar to those generated by the current model.…”

Section: Conjugated Polymersmentioning

confidence: 99%

Thermal Fluctuations Lead to Cumulative Disorder and Enhance Charge Transport in Conjugated Polymers

Zhang

Bombile

Weisen

et al. 2019

Macromol. Rapid Commun.

View full text Add to dashboard Cite

All conjugated polymers examined to date exhibit significant cumulative lattice disorder, although the origin of this disorder remains unclear. Using atomistic molecular dynamics (MD) simulations, the detailed structures for single crystals of a commonly studied conjugated polymer, poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) are obtained. It is shown that thermal fluctuations of thiophene rings lead to cumulative disorder of the lattice with an effective paracrystallinity of about 0.05 in the π–π stacking direction. The thermal‐fluctuation‐induced lattice disorder can in turn limit the apparent coherence length that can be observed in diffraction experiments. Calculating mobilities from simulated crystal structures demonstrates that thermal‐fluctuation‐induced lattice disorder even enhances charge transport in P3HT. The mean inter‐chain charge transfer integral is enhanced with increasing cumulative lattice disorder, which in turn leads to pathways for fast charge transport through crystals.

show abstract

“…Dreiding was chosen because of its capability to describe well the crystalline phase of poly(3-hexylthiophene) (P3HT). 75,76 It exhibits two local minima, one at ϕ = 0°(corresponding to the cis or SS-syn conformation) and another at ϕ = 180°( corresponding to the trans or SS-anti conformation), and a maximum at ϕ = 90°. The height of the potential at ϕ = 90°c orresponds to the energy barrier separating the cis from the trans conformation.…”

Section: Molecular Model and Simulation Detailsmentioning

confidence: 99%

Monte Carlo Algorithm Based on Internal Bridging Moves for the Atomistic Simulation of Thiophene Oligomers and Polymers

et al. 2018

View full text Add to dashboard Cite

We introduce a powerful Monte Carlo (MC) algorithm for the atomistic simulation of bulk models of oligo-and poly-thiophenes by redesigning MC moves originally developed for considerably simpler polymer structures and architectures, such as linear and branched polyethylene, to account for the ring structure of the thiophene monomer. Elementary MC moves implemented include bias reptation of an end thiophene ring, flip of an internal thiophene ring, rotation of an end thiophene ring, concerted rotation of three thiophene rings, rigid translation of an entire molecule, rotation of an entire molecule and volume fluctuation. In the implementation of all moves we assume that thiophene ring atoms remain rigid and strictly co-planar; on the other hand, inter-ring torsion and bond bending angles remain fully flexible subject to suitable potential energy functions. Test simulations with the new algorithm of an important thiophene oligomer, α-sexithiophene (α-6T), at a high enough temperature (above its isotropic-to-nematic phase transition) using a new united atom 2 model specifically developed for the purpose of this work provide predictions for the volumetric, conformational and structural properties that are remarkably close to those obtained from detailed atomistic Molecular Dynamics (MD) simulations using an all-atom model. The new algorithm is particularly promising for exploring the rich (and largely unexplored) phase behavior and nanoscale ordering of very long (also more complex) thiophene-based polymers which cannot be addressed by conventional MD methods due to the extremely long relaxation times characterizing chain dynamics in these systems.

show abstract

Modeling organic electronic materials: bridging length and time scales

Cited by 9 publications

References 81 publications

Controlling Molecular Doping in Organic Semiconductors

Controlling Molecular Doping in Organic Semiconductors

Thermal Fluctuations Lead to Cumulative Disorder and Enhance Charge Transport in Conjugated Polymers

Monte Carlo Algorithm Based on Internal Bridging Moves for the Atomistic Simulation of Thiophene Oligomers and Polymers

Contact Info

Product

Resources

About