De Novo Simulation of Charge Transport through Organic Single-Carrier Devices

Kaiser, Simon; Kotadiya, Naresh B.; Rohloff, Roland; Fediai, Artem; Symalla, Franz; Neumann, Tobias; Wetzelaer, Gert‐Jan A. H.; Blom, Paul W. M.; Wenzel, Wolfgang

doi:10.1021/acs.jctc.1c00584

Cited by 5 publications

(10 citation statements)

References 45 publications

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“…As the systems which are generated in this way are too small to be used in the kMC transport model (Massé et al, 2014) we use a stochastic extension scheme (Baumeier et al, 2012;Symalla et al, 2016). This scheme has been used to investigate charge and energy transport in emissive layers (Symalla et al, 2020a;Symalla et al, 2020b), doped injection layers (Symalla et al, 2020a), single-carrier devices (Kaiser et al, 2021) and OLEDs (Symalla et al, 2018;Symalla et al, 2019) de novo.…”

Section: Introductionmentioning

confidence: 99%

De Novo Calculation of the Charge Carrier Mobility in Amorphous Small Molecule Organic Semiconductors

et al. 2021

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Organic semiconductors (OSC) are key components in applications such as organic photovoltaics, organic sensors, transistors and organic light emitting diodes (OLED). OSC devices, especially OLEDs, often consist of multiple layers comprising one or more species of organic molecules. The unique properties of each molecular species and their interaction determine charge transport in OSCs—a key factor for device performance. The small charge carrier mobility of OSCs compared to inorganic semiconductors remains a major limitation of OSC device performance. Virtual design can support experimental R&D towards accelerated R&D of OSC compounds with improved charge transport. Here we benchmark a de novo multiscale workflow to compute the charge carrier mobility solely on the basis of the molecular structure: We generate virtual models of OSC thin films with atomistic resolution, compute the electronic structure of molecules in the thin films using a quantum embedding procedure and simulate charge transport with kinetic Monte-Carlo protocol. We show that for 15 common amorphous OSC the computed zero-field and field-dependent mobility are in good agreement with experimental data, proving this approach to be an effective virtual design tool for OSC materials and devices.

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Section: Introductionmentioning

confidence: 99%

De Novo Calculation of the Charge Carrier Mobility in Amorphous Small Molecule Organic Semiconductors

et al. 2021

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“…We performed the simulations on systems represented by simple cubic latices ( Bässler, 1993 ; Pasveer et al, 2005 ) for each organic layer with a lattice constant was d = 1 nm ( Mesta et al, 2013 ). Electronic properties like the ionization potential (IP) of the host material, electron affinity (EA) of the dopants or energetic disorder were treated as parameters and could easily be replaced by data from first-principle calculations, as done in previous works ( Friederich et al, 2016 ; Kaiser et al, 2021 ). Charge carrier transport, charge injection (ejection) and doping activation with the kMC package LightForge (LF) ( Symalla et al, 2016 ).…”

Section: Methodsmentioning

confidence: 99%

“…The enormous number of potential materials and device architectures turns the development of novel materials and devices into a time- and resource-intensive task. In recent years, multiscale computational methods successfully predicted charge carrier mobility in pure materials ( Friederich et al, 2014 ; Massé et al, 2016 ; Kotadiya et al, 2018 ) and guest-host systems ( Symalla et al, 2016 ), current voltage characteristics ( Mesta et al, 2013 ; Kaiser et al, 2021 ) and photoluminescent quenching ( Symalla et al, 2020b ) thus gaining relevance for the organic electronics community to be used as a supporting tool in device development and optimization ( Andrienko, 2018 ; Friederich et al, 2019 ). Established simulation methods to model charge transport, charge injection (extraction) in OLEDs are drift-diffusion methods (DD) ( Rossi et al, 2020 ; Doan et al, 2019 ), macroscopic equivalent-circuit techniques ( Nowy et al, 2010 ), and microscopic methods like kinetic Monte Carlo (kMC) or master equation approaches (ME) ( Zojer, 2021 ).…”

Section: Introductionmentioning

confidence: 99%

Systematic kMC Study of Doped Hole Injection Layers in Organic Electronics

et al. 2022

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Organic light emitting diodes (OLED) play an important role in commercial displays and are promising candidates for energy-efficient lighting applications. Although they have been continuously developed since their discovery in 1987, some unresolved challenges remain. The performance of OLEDs is determined by a multifaceted interplay of materials and device architectures. A commonly used technique to overcome the charge injection barrier from the electrodes to the organic layers, are doped injection layers. The optimization of doped injection layers is critical for high-efficiency OLED devices, but has been driven mainly by chemical intuition and experimental experience, slowing down the progress in this field. Therefore, computer-aided methods for material and device modeling are promising tools to accelerate the device development process. In this work, we studied the effect of doped hole injection layers on the injection barrier in dependence on material and layer properties by using a parametric kinetic Monte Carlo model. We were able to quantitatively elucidate the influence of doping concentration, material properties, and layer thickness on the injection barrier and device conductivity, leading to the conclusion that our kMC model is suitable for virtual device design.

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“…Several works that investigated charge carrier mobilities in amorphous OSCs have extensively covered energetic disorder. Some of these works − assumed a frozen structure approximation, which is equivalent to analyzing a single snapshot of a molecular dynamics (MD) trajectory. However, dynamic effects on energetic disorder have been explored in several studies, − albeit in either crystalline or partially ordered systems.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Effects on Hole Transport in Amorphous Organic Semiconductors: a Combined QM/MM and kMC Study

Özdemir

inanlou

Symalla

et al. 2023

J. Chem. Theory Comput.

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Small-molecule-based amorphous organic semiconductors (OSCs) are essential components of organic photovoltaics and organic light-emitting diodes. The charge carrier mobility of these materials is an integral and limiting factor in regard to their performance. Integrated computational models for the hole mobility, taking into account structural disorder in systems of several thousand molecules, have been the object of research in the past. Due to static and dynamic contributions to the total structural disorder, efficient strategies to sample the charge transfer parameters become necessary. In this paper, we investigate the impact of structural disorder in amorphous OSCs on the transfer parameters and charge mobilities in different materials. We present a sampling strategy for incorporating static and dynamic structural disorder which are based on QM/MM methods using semiempirical Hamiltonians and extensive MD sampling. We show how the disorder affects the distributions of HOMO energies and intermolecular couplings and validate the results using kinetic Monte Carlo simulations of the mobility. We find that dynamic disorder causes an order of magnitude difference in the calculated mobility between morphologies of the same material. Our method allows the sampling of disorder in HOMO energies and couplings, and the statistical analysis enables us to characterize the relevant time scales on which charge transfer occurs in these complex materials. The findings presented here shed light on the interplay of the fluctuating amorphous matrix with charge carrier transport and aid in the development of a better understanding of these complex processes.

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De Novo Simulation of Charge Transport through Organic Single-Carrier Devices

Cited by 5 publications

References 45 publications

De Novo Calculation of the Charge Carrier Mobility in Amorphous Small Molecule Organic Semiconductors

De Novo Calculation of the Charge Carrier Mobility in Amorphous Small Molecule Organic Semiconductors

Systematic kMC Study of Doped Hole Injection Layers in Organic Electronics

Dynamic Effects on Hole Transport in Amorphous Organic Semiconductors: a Combined QM/MM and kMC Study

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