1
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Hung CM, Wang SF, Chao WC, Li JL, Chen BH, Lu CH, Tu KY, Yang SD, Hung WY, Chi Y, Chou PT. High-performance near-infrared OLEDs maximized at 925 nm and 1022 nm through interfacial energy transfer. Nat Commun 2024; 15:4664. [PMID: 38821968 PMCID: PMC11143248 DOI: 10.1038/s41467-024-49127-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 05/23/2024] [Indexed: 06/02/2024] Open
Abstract
Using a transfer printing technique, we imprint a layer of a designated near-infrared fluorescent dye BTP-eC9 onto a thin layer of Pt(II) complex, both of which are capable of self-assembly. Before integration, the Pt(II) complex layer gives intense deep-red phosphorescence maximized at ~740 nm, while the BTP-eC9 layer shows fluorescence at > 900 nm. Organic light emitting diodes fabricated under the imprinted bilayer architecture harvest most of Pt(II) complex phosphorescence, which undergoes triplet-to-singlet energy transfer to the BTP-eC9 dye, resulting in high-intensity hyperfluorescence at > 900 nm. As a result, devices achieve 925 nm emission with external quantum efficiencies of 2.24% (1.94 ± 0.18%) and maximum radiance of 39.97 W sr-1 m-2. Comprehensive morphology, spectroscopy and device analyses support the mechanism of interfacial energy transfer, which also is proved successful for BTPV-eC9 dye (1022 nm), making bright and far-reaching the prospective of hyperfluorescent OLEDs in the near-infrared region.
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Affiliation(s)
- Chieh-Ming Hung
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Sheng-Fu Wang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Wei-Chih Chao
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Jian-Liang Li
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Bo-Han Chen
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
| | - Chih-Hsuan Lu
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
| | - Kai-Yen Tu
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Shang-Da Yang
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
| | - Wen-Yi Hung
- Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, Taiwan
| | - Yun Chi
- Department of Materials Sciences and Engineering and Department of Chemistry, City University of Hong Kong, Hong Kong SAR, China.
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei, Taiwan.
- Center for Emerging Materials and Advanced Devices, National Taiwan University, Taipei, Taiwan.
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2
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Mac Ciarnáin R, Mo HW, Nagayoshi K, Fujimoto H, Harada K, Gehlhaar R, Ke TH, Heremans P, Adachi C. A Thermally Activated Delayed Fluorescence Green OLED with 4500 h Lifetime and 20% External Quantum Efficiency by Optimizing the Emission Zone using a Single-Emission Spectrum Technique. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2201409. [PMID: 35581173 DOI: 10.1002/adma.202201409] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 05/07/2022] [Indexed: 06/15/2023]
Abstract
Device optimization of light-emitting diodes (LEDs) targets the most efficient conversion of electrically injected charges into emitted light. The emission zone in an LED is where charges recombine and light is emitted from. It is believed that the emission zone is strongly linked to device efficiency and lifetime. However, the emission zone size is below the optical diffraction limit, so it is difficult to measure. An accessible method based on a single emission spectrum that enables emission zone measurements with sub-second time resolution is shown. A procedure is introduced to study and control the emission zone of an LED system and correlate it with device performance. A thermally activated delayed fluorescence organic LED emission zone is experimentally measured over all luminescing current densities, while varying the device structure and while ageing. The emission zone is shown to be finely controlled by emitter doping because electron transport via the emitter is the charge-transport bottleneck of the system. Suspected quenching/degradation mechanisms are linked with the emission zone changes, device structure variation, and ageing. Using these findings, a device with an ultralong 4500 h T95 lifetime at 1000 cd m-2 with 20% external quantum efficiency is shown.
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Affiliation(s)
- Rossa Mac Ciarnáin
- imec, Kapeldreef 75, Leuven, B3001, Belgium
- KU Leuven, Kasteelpark Arenberg 10, Leuven, B3001, Belgium
| | - Hin Wai Mo
- i 3-opera, 5-14 Kyudai-shimmachi, Nishi, Fukuoka, 819-0388, Japan
| | - Kaori Nagayoshi
- i 3-opera, 5-14 Kyudai-shimmachi, Nishi, Fukuoka, 819-0388, Japan
| | - Hiroshi Fujimoto
- i 3-opera, 5-14 Kyudai-shimmachi, Nishi, Fukuoka, 819-0388, Japan
- OPERA Research Group, Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Kentaro Harada
- i 3-opera, 5-14 Kyudai-shimmachi, Nishi, Fukuoka, 819-0388, Japan
- OPERA Research Group, Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | | | | | - Paul Heremans
- imec, Kapeldreef 75, Leuven, B3001, Belgium
- KU Leuven, Kasteelpark Arenberg 10, Leuven, B3001, Belgium
| | - Chihaya Adachi
- i 3-opera, 5-14 Kyudai-shimmachi, Nishi, Fukuoka, 819-0388, Japan
- OPERA Research Group, Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
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3
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Hauenstein C, Gottardi S, Torun E, Coehoorn R, van Eersel H. Identification of OLED Degradation Scenarios by Kinetic Monte Carlo Simulations of Lifetime Experiments. Front Chem 2022; 9:823210. [PMID: 35155385 PMCID: PMC8828587 DOI: 10.3389/fchem.2021.823210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 12/21/2021] [Indexed: 11/23/2022] Open
Abstract
We show how three-dimensions kinetic Monte Carlo simulations can be used to carry out an operational lifetime study of thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) and to deduce the sensitivity to various degradation scenarios. The approach is demonstrated for an experimentally well-characterized efficient green-emitting device. The simulation workflow includes an equilibration phase, an equilibrated pristine state phase and a degradation phase. Acceleration of the simulations by extrapolation from simulations at large current densities makes the simulation time realistically feasible. Such a procedure is also often followed in experimental studies. Degradation is assumed to be triggered by exciton-polaron quenching and exciton-exciton annihilation processes. A comparison of the simulated and experimental time-dependence of the luminance decay provides the probability that a degradation-triggering event leads to the formation of a degraded molecule. For the TADF OLED that has been studied, this parameter is only weakly dependent on the assumed scenario, provided that the degraded molecules are assumed to form trap sites, and is found to be ∼(0.2−0.7)×10−9. The approach is expected to enable systematic in silico studies of the operational lifetime and its sensitivity to the material composition, layer structure, charge carrier balance, and the use of refined device principles such as hyperfluorescence.
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Affiliation(s)
- Christoph Hauenstein
- Simbeyond B.V., Eindhoven, Netherlands
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, Netherlands
- *Correspondence: Christoph Hauenstein,
| | | | | | - Reinder Coehoorn
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, Netherlands
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4
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Özdemir AD, Kaiser S, Neumann T, Symalla F, Wenzel W. Systematic kMC Study of Doped Hole Injection Layers in Organic Electronics. Front Chem 2022; 9:809415. [PMID: 35118050 PMCID: PMC8804170 DOI: 10.3389/fchem.2021.809415] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/13/2021] [Indexed: 11/13/2022] Open
Abstract
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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Affiliation(s)
- Ali Deniz Özdemir
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Simon Kaiser
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | | | | | - Wolfgang Wenzel
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- *Correspondence: Wolfgang Wenzel ,
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5
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Ellis M, Yang H, Giannini S, Ziogos OG, Blumberger J. Impact of Nanoscale Morphology on Charge Carrier Delocalization and Mobility in an Organic Semiconductor. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2104852. [PMID: 34558126 DOI: 10.1002/adma.202104852] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/11/2021] [Indexed: 06/13/2023]
Abstract
A central challenge of organic semiconductor research is to make cheap, disordered materials that exhibit high electrical conductivity. Unfortunately, this endeavor is hampered by the poor fundamental understanding of the relationship between molecular packing structure and charge carrier mobility. Here a novel computational methodology is presented that fills this gap. Using a melt-quench procedure it is shown that amorphous pentacene spontaneously self-assembles to nanocrystalline structures that, at long quench times, form the characteristic herringbone layer of the single crystal. Quantum dynamical simulations of electron hole transport show a clear correlation between the crystallinity of the sample, the quantum delocalization, and the mobility of the charge carrier. Surprisingly, the long-held belief that charge carriers form relatively localized polarons in disordered OS is only valid for fully amorphous structures-for nanocrystalline and crystalline samples, significant charge carrier delocalization over several nanometers occurs that underpins their improved conductivities. The good agreement with experimentally available data makes the presented methodology a robust computational tool for the predictive engineering of disordered organic materials.
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Affiliation(s)
- Matthew Ellis
- Department of Physics and Astronomy and Thomas Young Centre London, University College London, Gower Street, London, WC1E 6BT, UK
| | - Hui Yang
- Department of Physics and Astronomy and Thomas Young Centre London, University College London, Gower Street, London, WC1E 6BT, UK
| | - Samuele Giannini
- Department of Physics and Astronomy and Thomas Young Centre London, University College London, Gower Street, London, WC1E 6BT, UK
| | - Orestis G Ziogos
- Department of Physics and Astronomy and Thomas Young Centre London, University College London, Gower Street, London, WC1E 6BT, UK
| | - Jochen Blumberger
- Department of Physics and Astronomy and Thomas Young Centre London, University College London, Gower Street, London, WC1E 6BT, UK
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6
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Aslanidis E, Skotadis E, Tsoukalas D. Simulation tool for predicting and optimizing the performance of nanoparticle based strain sensors. NANOTECHNOLOGY 2021; 32:275501. [PMID: 33761486 DOI: 10.1088/1361-6528/abf195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
In this work a Monte-Carlo tool simulating platinum nanoparticle (NP) based strain-sensors, on flexible substrates, is presented. The tool begins by randomly placing the NPs on the simulation area, with the ability to tune the NP surface coverage. After the calculation of the conductive paths that were generated in the previous step, the whole system is represented with an equivalent circuit; the NPs and the NP clusters act as nodes and the inter-particle gaps as resistances. The effective resistance is then calculated with the use of a Laplacian Matrix, which has proven extremely effective in significantly reducing the overall computational time. The simulation results are then benchmarked with experimental measurements from actual strain-sensing devices. The software is capable of predicting the strain-sensitivity for different NP sizes as well as surface coverages, emerging as a powerful computational tool for design-optimization of NP based devices in polymeric substrates, while it could well be extended to other nanocomposite materials used in flexible or stretchable electronic applications.
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Affiliation(s)
- Evangelos Aslanidis
- Department of Applied Physics, National Technical University of Athens, Athens, 15780, Greece
| | - Evangelos Skotadis
- Department of Applied Physics, National Technical University of Athens, Athens, 15780, Greece
| | - Dimitris Tsoukalas
- Department of Applied Physics, National Technical University of Athens, Athens, 15780, Greece
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7
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Li H, Brédas JL. Developing molecular-level models for organic field-effect transistors. Natl Sci Rev 2021; 8:nwaa167. [PMID: 35371512 PMCID: PMC8966973 DOI: 10.1093/nsr/nwaa167] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/19/2020] [Accepted: 07/09/2020] [Indexed: 11/14/2022] Open
Abstract
Organic field-effect transistors (OFETs) are not only functional devices but also represent an important tool for measuring the charge-transport properties of organic semiconductors (OSs). Thus, efforts to understand the performance and characteristics of OFET devices are not only useful in helping achieve higher device efficiencies but also critical to ensuring accuracy in the evaluations of OS charge mobilities. These studies rely on OFET device models, which connect the measured current characteristics to the properties of the OSs. Developing such OFET models requires good knowledge of the charge-transport processes in OSs. In device active layers, the OS thin films are either amorphous (e.g. in organic light-emitting diodes and organic solar cells) or crystalline (e.g. those optimized for charge transport in OFETs). When the electronic couplings between adjacent OS molecules or polymer chain segments are weak, the charge-transport mechanism is dominated by hopping processes, which is the context in which we frame the discussion in this Review. Factors such as disorder, mobility anisotropy, traps, grain boundaries or film morphology all impact charge transport. To take these features fully into account in an OFET device model requires considering a nano-scale, molecular-level resolution. Here, we discuss the recent development of such molecular-resolution OFET models based on a kinetic Monte Carlo approach relevant to the hopping regime. We also briefly describe the applicability of these models to high-mobility OFETs, where we underline the need to extend them to incorporate aspects related to charge delocalization.
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Affiliation(s)
- Haoyuan Li
- School of Chemistry and Biochemistry, and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, GA 30332,
USA
- Department of Chemistry and Biochemistry, University of
Arizona, Tucson, AZ 85721, USA
| | - Jean-Luc Brédas
- School of Chemistry and Biochemistry, and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, GA 30332,
USA
- Department of Chemistry and Biochemistry, University of
Arizona, Tucson, AZ 85721, USA
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8
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Irfan A, Imran M, Thomas R, Basra MAR, Ullah S, Al-Sehemi AG, Assiri MA. Exploring the effect of oligothiophene and acene cores on the optoelectronic properties and enhancing p- and n-type ability of semiconductor materials. J Sulphur Chem 2020. [DOI: 10.1080/17415993.2020.1830401] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Ahmad Irfan
- Research Center for Advanced Materials Science (RCAMS), King Khalid University, Abha, Saudi Arabia
- Department of Chemistry, Faculty of Science, King Khalid University, Abha, Saudi Arabia
| | - Muhammad Imran
- Department of Chemistry, Faculty of Science, King Khalid University, Abha, Saudi Arabia
| | - Renjith Thomas
- Department of Chemistry, St Berchmans College (Autonomous), Kerala, India
| | | | - Sami Ullah
- Department of Chemistry, Faculty of Science, King Khalid University, Abha, Saudi Arabia
| | - Abdullah G. Al-Sehemi
- Research Center for Advanced Materials Science (RCAMS), King Khalid University, Abha, Saudi Arabia
- Department of Chemistry, Faculty of Science, King Khalid University, Abha, Saudi Arabia
| | - Mohammed A. Assiri
- Department of Chemistry, Faculty of Science, King Khalid University, Abha, Saudi Arabia
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9
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High energy acceptor states strongly enhance exciton transfer between metal organic phosphorescent dyes. Nat Commun 2020; 11:1292. [PMID: 32157092 PMCID: PMC7064524 DOI: 10.1038/s41467-020-15034-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 02/12/2020] [Indexed: 12/05/2022] Open
Abstract
Exciton management in organic light-emitting diodes (OLEDs) is vital for improving efficiency, reducing device aging, and creating new device architectures. In particular in white OLEDs, exothermic Förster-type exciton transfer, e.g. from blue to red emitters, plays a crucial role. It is known that a small exothermicity partially overcomes the spectral Stokes shift, enhancing the fraction of resonant donor-acceptor pair states and thus the Förster transfer rate. We demonstrate here a second enhancement mechanism, setting in when the exothermicity exceeds the Stokes shift: transfer to multiple higher-lying electronically excited states of the acceptor molecules. Using a recently developed computational method we evaluate the Förster transfer rate for 84 different donor–acceptor pairs of phosphorescent emitters. As a result of the enhancement the Förster radius tends to increase with increasing exothermicity, from around 1 nm to almost 4 nm. The enhancement becomes particularly strong when the excited states have a large spin-singlet character. Exciton management in phosphorescent organic light-emitting diodes is critical to the optimal design and performance of these devices. Here, the authors report a computational method to elucidate the enhancement in exothermic exciton transfer between different phosphorescent emitters.
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10
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Symalla F, Heidrich S, Friederich P, Strunk T, Neumann T, Minami D, Jeong D, Wenzel W. Multiscale Simulation of Photoluminescence Quenching in Phosphorescent OLED Materials. ADVANCED THEORY AND SIMULATIONS 2020. [DOI: 10.1002/adts.201900222] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Franz Symalla
- Nanomatch GmbHHermann‐von‐Helmholtz‐Platz 1 Bau 640 76344 Eggenstein‐Leopoldshafen Germany
| | - Shahriar Heidrich
- Institute of Nanotechnology (INT)Karlsruhe Institute of Technology (KIT) Hermann‐von‐Helmholtz‐Platz 1 76344 Eggenstein‐Leopoldshafen Germany
| | - Pascal Friederich
- Institute of Nanotechnology (INT)Karlsruhe Institute of Technology (KIT) Hermann‐von‐Helmholtz‐Platz 1 76344 Eggenstein‐Leopoldshafen Germany
| | - Timo Strunk
- Nanomatch GmbHHermann‐von‐Helmholtz‐Platz 1 Bau 640 76344 Eggenstein‐Leopoldshafen Germany
| | - Tobias Neumann
- Nanomatch GmbHHermann‐von‐Helmholtz‐Platz 1 Bau 640 76344 Eggenstein‐Leopoldshafen Germany
| | - Daiki Minami
- Samsung Advanced Institute of TechnologySamsung Electronics Co. Ltd. 130 Samsung‐ro, Yeongtong‐gu Suwon‐si Gyeonggi‐do 16678 Republic of Korea
| | - Daun Jeong
- Samsung Advanced Institute of TechnologySamsung Electronics Co. Ltd. 130 Samsung‐ro, Yeongtong‐gu Suwon‐si Gyeonggi‐do 16678 Republic of Korea
| | - Wolfgang Wenzel
- Institute of Nanotechnology (INT)Karlsruhe Institute of Technology (KIT) Hermann‐von‐Helmholtz‐Platz 1 76344 Eggenstein‐Leopoldshafen Germany
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11
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Friederich P, Fediai A, Kaiser S, Konrad M, Jung N, Wenzel W. Toward Design of Novel Materials for Organic Electronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1808256. [PMID: 31012166 DOI: 10.1002/adma.201808256] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Indexed: 06/09/2023]
Abstract
Materials for organic electronics are presently used in prominent applications, such as displays in mobile devices, while being intensely researched for other purposes, such as organic photovoltaics, large-area devices, and thin-film transistors. Many of the challenges to improve and optimize these applications are material related and there is a nearly infinite chemical space that needs to be explored to identify the most suitable material candidates. Established experimental approaches struggle with the size and complexity of this chemical space. Herein, the development of simulation methods is addressed, with a particular emphasis on predictive multiscale protocols, to complement experimental research in the identification of novel materials and illustrate the potential of these methods with a few prominent recent applications. Finally, the potential of machine learning and methods based on artificial intelligence is discussed to further accelerate the search for new materials.
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Affiliation(s)
- Pascal Friederich
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
- Department of Chemistry, University of Toronto, 80 St. George Street, M5S 3H6, Toronto, Ontario, Canada
| | - Artem Fediai
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Simon Kaiser
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Manuel Konrad
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Nicole Jung
- Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
| | - Wolfgang Wenzel
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
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12
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Tuning the charge flow between Marcus regimes in an organic thin-film device. Nat Commun 2019; 10:2089. [PMID: 31064992 PMCID: PMC6504872 DOI: 10.1038/s41467-019-10114-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 04/15/2019] [Indexed: 11/08/2022] Open
Abstract
Marcus’s theory of electron transfer, initially formulated six decades ago for redox reactions in solution, is now of great importance for very diverse scientific communities. The molecular scale tunability of electronic properties renders organic semiconductor materials in principle an ideal platform to test this theory. However, the demonstration of charge transfer in different Marcus regions requires a precise control over the driving force acting on the charge carriers. Here, we make use of a three-terminal hot-electron molecular transistor, which lets us access unconventional transport regimes. Thanks to the control of the injection energy of hot carriers in the molecular thin film we induce an effective negative differential resistance state that is a direct consequence of the Marcus Inverted Region. To demonstrate charge transfer in different Marcus regimes in an organic semiconductor, precise tuning of the material’s electronic properties is required. Here, the authors use a three-terminal hot-electron technique to access the Marcus regimes for electronic transport in organic thin films.
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13
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Roland S, Kniepert J, Love JA, Negi V, Liu F, Bobbert P, Melianas A, Kemerink M, Hofacker A, Neher D. Equilibrated Charge Carrier Populations Govern Steady-State Nongeminate Recombination in Disordered Organic Solar Cells. J Phys Chem Lett 2019; 10:1374-1381. [PMID: 30829040 DOI: 10.1021/acs.jpclett.9b00516] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We employed bias-assisted charge extraction techniques to investigate the transient and steady-state recombination of photogenerated charge carriers in complete devices of a disordered polymer-fullerene blend. Charge recombination is shown to be dispersive, with a significant slowdown of the recombination rate over time, consistent with the results from kinetic Monte Carlo simulations. Surprisingly, our experiments reveal little to no contributions from early time recombination of nonequilibrated charge carriers to the steady-state recombination properties. We conclude that energetic relaxation of photogenerated carriers outpaces any significant nongeminate recombination under application-relevant illumination conditions. With equilibrated charges dominating the steady-state recombination, quasi-equilibrium concepts appear suited for describing the open-circuit voltage of organic solar cells despite pronounced energetic disorder.
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Affiliation(s)
- Steffen Roland
- Department of Physics and Astronomy , Universität Potsdam , 14476 Potsdam , Germany
| | - Juliane Kniepert
- Department of Physics and Astronomy , Universität Potsdam , 14476 Potsdam , Germany
| | - John A Love
- Department of Physics and Astronomy , Universität Potsdam , 14476 Potsdam , Germany
| | - Vikas Negi
- Molecular Materials and Nanosystems, Department of Applied Physics , Eindhoven University of Technology , P.O. Box 513, 5600 MB Eindhoven , The Netherlands
| | - Feilong Liu
- Molecular Materials and Nanosystems, Department of Applied Physics , Eindhoven University of Technology , P.O. Box 513, 5600 MB Eindhoven , The Netherlands
| | - Peter Bobbert
- Molecular Materials and Nanosystems, Department of Applied Physics , Eindhoven University of Technology , P.O. Box 513, 5600 MB Eindhoven , The Netherlands
| | - Armantas Melianas
- Biomolecular and Organic Electronics, Department of Physics, Chemistry and Biology , Linköping University , 58183 Linköping , Sweden
| | - Martijn Kemerink
- Complex Materials and Devices, Department of Physics, Chemistry and Biology , Linköping University , 58183 Linköping , Sweden
| | - Andreas Hofacker
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics , Technische Universität Dresden , 01187 Dresden , Germany
| | - Dieter Neher
- Department of Physics and Astronomy , Universität Potsdam , 14476 Potsdam , Germany
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14
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Pashaei B, Karimi S, Shahroosvand H, Abbasi P, Pilkington M, Bartolotta A, Fresta E, Fernandez-Cestau J, Costa RD, Bonaccorso F. Polypyridyl ligands as a versatile platform for solid-state light-emitting devices. Chem Soc Rev 2019; 48:5033-5139. [DOI: 10.1039/c8cs00075a] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A comprehensive review of tuneable polypyridine complexes as the emissive components of OLED and LEC devices is presented, with a view to bridging the gap between molecular design and commercialization.
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Affiliation(s)
- Babak Pashaei
- Group for Molecular Engineering of Advanced Functional Materials (GMA)
- Department of Chemistry
- University of Zanjan
- Zanjan
- Iran
| | - Soheila Karimi
- Group for Molecular Engineering of Advanced Functional Materials (GMA)
- Department of Chemistry
- University of Zanjan
- Zanjan
- Iran
| | - Hashem Shahroosvand
- Group for Molecular Engineering of Advanced Functional Materials (GMA)
- Department of Chemistry
- University of Zanjan
- Zanjan
- Iran
| | - Parisa Abbasi
- Department of Chemistry
- Brock University
- St. Catharines
- Canada
| | | | | | - Elisa Fresta
- IMDEA Materials Institute
- Madrid
- Spain
- Universidad Autónoma de Madrid
- Departamento de Física Aplicada
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15
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Chiykowski VA, Cao Y, Tan H, Tabor DP, Sargent EH, Aspuru‐Guzik A, Berlinguette CP. Precise Control of Thermal and Redox Properties of Organic Hole‐Transport Materials. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201810809] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Valerie A. Chiykowski
- Department of Chemistry The University of British Columbia 2036 Main Mall Vancouver British Columbia V6T 1Z1 Canada
| | - Yang Cao
- Department of Chemistry The University of British Columbia 2036 Main Mall Vancouver British Columbia V6T 1Z1 Canada
| | - Hairen Tan
- Department of Electrical and Computer Engineering University of Toronto 10 King's College Road Toronto Ontario M5S 3G4 Canada
| | - Daniel P. Tabor
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
| | - Edward H. Sargent
- Department of Electrical and Computer Engineering University of Toronto 10 King's College Road Toronto Ontario M5S 3G4 Canada
| | - Alán Aspuru‐Guzik
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
- Department of Chemistry and Department of Computer Science University of Toronto Toronto Ontario M5S 3H6 Canada
- Vector Institute Toronto ON M5G 1M1 Canada
| | - Curtis P. Berlinguette
- Department of Chemistry The University of British Columbia 2036 Main Mall Vancouver British Columbia V6T 1Z1 Canada
- Department of Chemical and Biological Engineering The University of British Columbia 2360 East Mall Vancouver British Columbia V6Y 1Z3 Canada
- Stewart Blusson Quantum Matter Institute The University of British Columbia 2355 East Mall Vancouver British Columbia V6T 1Z4 Canada
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16
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Chiykowski VA, Cao Y, Tan H, Tabor DP, Sargent EH, Aspuru‐Guzik A, Berlinguette CP. Precise Control of Thermal and Redox Properties of Organic Hole‐Transport Materials. Angew Chem Int Ed Engl 2018; 57:15529-15533. [PMID: 30267466 DOI: 10.1002/anie.201810809] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Valerie A. Chiykowski
- Department of Chemistry The University of British Columbia 2036 Main Mall Vancouver British Columbia V6T 1Z1 Canada
| | - Yang Cao
- Department of Chemistry The University of British Columbia 2036 Main Mall Vancouver British Columbia V6T 1Z1 Canada
| | - Hairen Tan
- Department of Electrical and Computer Engineering University of Toronto 10 King's College Road Toronto Ontario M5S 3G4 Canada
| | - Daniel P. Tabor
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
| | - Edward H. Sargent
- Department of Electrical and Computer Engineering University of Toronto 10 King's College Road Toronto Ontario M5S 3G4 Canada
| | - Alán Aspuru‐Guzik
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
- Department of Chemistry and Department of Computer Science University of Toronto Toronto Ontario M5S 3H6 Canada
- Vector Institute Toronto ON M5G 1M1 Canada
| | - Curtis P. Berlinguette
- Department of Chemistry The University of British Columbia 2036 Main Mall Vancouver British Columbia V6T 1Z1 Canada
- Department of Chemical and Biological Engineering The University of British Columbia 2360 East Mall Vancouver British Columbia V6Y 1Z3 Canada
- Stewart Blusson Quantum Matter Institute The University of British Columbia 2355 East Mall Vancouver British Columbia V6T 1Z4 Canada
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17
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Popp J, Kaiser W, Gagliardi A. Impact of Phosphorescent Sensitizers and Morphology on the Photovoltaic Performance in Organic Solar Cells. ADVANCED THEORY AND SIMULATIONS 2018. [DOI: 10.1002/adts.201800114] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Johannes Popp
- Department of Electrical and Computer EngineeringTechnical University of MunichArcisstraße 21 80333 Munich Germany
| | - Waldemar Kaiser
- Department of Electrical and Computer EngineeringTechnical University of MunichArcisstraße 21 80333 Munich Germany
| | - Alessio Gagliardi
- Department of Electrical and Computer EngineeringTechnical University of MunichArcisstraße 21 80333 Munich Germany
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18
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Regnat M, Pernstich KP, Züfle S, Ruhstaller B. Analysis of the Bias-Dependent Split Emission Zone in Phosphorescent OLEDs. ACS APPLIED MATERIALS & INTERFACES 2018; 10:31552-31559. [PMID: 30148341 DOI: 10.1021/acsami.8b09595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
From s-polarized, angle-dependent measurements of the electroluminescence spectra in a three-layer phosphorescent organic light-emitting diode, we calculate the exciton distribution inside the 35 nm thick emission layer. The shape of the exciton profile changes with the applied bias due to differing field dependencies of the electron and hole mobilities. A split emission zone with high exciton densities at both sides of the emission layer is obtained, which is explained by the presence of energy barriers and similar electron and hole mobilities. A peak in the transient electroluminescence signal after turn-off and the application of a reverse bias is identified as a signature of a split emission zone.
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Affiliation(s)
- Markus Regnat
- Institute of Computational Physics , Zurich University of Applied Sciences (ZHAW) , Technikumstrasse 9 , 8400 Winterthur , Switzerland
- Institut des Matériaux , Ecole Polytechnique Fédérale de Lausanne, EPFL , Station 12 , 1015 Lausanne , Switzerland
| | - Kurt P Pernstich
- Institute of Computational Physics , Zurich University of Applied Sciences (ZHAW) , Technikumstrasse 9 , 8400 Winterthur , Switzerland
| | - Simon Züfle
- Institute of Computational Physics , Zurich University of Applied Sciences (ZHAW) , Technikumstrasse 9 , 8400 Winterthur , Switzerland
- Fluxim AG , Katharina-Sulzer-Platz 2 , 8400 Winterthur , Switzerland
| | - Beat Ruhstaller
- Institute of Computational Physics , Zurich University of Applied Sciences (ZHAW) , Technikumstrasse 9 , 8400 Winterthur , Switzerland
- Fluxim AG , Katharina-Sulzer-Platz 2 , 8400 Winterthur , Switzerland
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19
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Rosławska A, Merino P, Große C, Leon CC, Gunnarsson O, Etzkorn M, Kuhnke K, Kern K. Single Charge and Exciton Dynamics Probed by Molecular-Scale-Induced Electroluminescence. NANO LETTERS 2018; 18:4001-4007. [PMID: 29799760 DOI: 10.1021/acs.nanolett.8b01489] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Excitons and their constituent charge carriers play the central role in electroluminescence mechanisms determining the ultimate performance of organic optoelectronic devices. The involved processes and their dynamics are often studied with time-resolved techniques limited by spatial averaging that obscures the properties of individual electron-hole pairs. Here, we overcome this limit and characterize single charge and exciton dynamics at the nanoscale by using time-resolved scanning tunneling microscopy-induced luminescence (TR-STML) stimulated with nanosecond voltage pulses. We use isolated defects in C60 thin films as a model system into which we inject single charges and investigate the formation dynamics of a single exciton. Tunable hole and electron injection rates are obtained from a kinetic model that reproduces the measured electroluminescent transients. These findings demonstrate that TR-STML can track dynamics at the quantum limit of single charge injection and can be extended to other systems and materials important for nanophotonic devices.
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Affiliation(s)
- Anna Rosławska
- Max Planck Institute for Solid State Research , Heisenbergstraße 1 , 70569 Stuttgart , Germany
| | - Pablo Merino
- Max Planck Institute for Solid State Research , Heisenbergstraße 1 , 70569 Stuttgart , Germany
| | - Christoph Große
- Max Planck Institute for Solid State Research , Heisenbergstraße 1 , 70569 Stuttgart , Germany
| | - Christopher C Leon
- Max Planck Institute for Solid State Research , Heisenbergstraße 1 , 70569 Stuttgart , Germany
| | - Olle Gunnarsson
- Max Planck Institute for Solid State Research , Heisenbergstraße 1 , 70569 Stuttgart , Germany
| | - Markus Etzkorn
- Max Planck Institute for Solid State Research , Heisenbergstraße 1 , 70569 Stuttgart , Germany
| | - Klaus Kuhnke
- Max Planck Institute for Solid State Research , Heisenbergstraße 1 , 70569 Stuttgart , Germany
| | - Klaus Kern
- Max Planck Institute for Solid State Research , Heisenbergstraße 1 , 70569 Stuttgart , Germany
- Institut de Physique , École Polytechnique Fédérale de Lausanne , 1015 Lausanne , Switzerland
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20
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Lorenzoni A, Mosca Conte A, Pecchia A, Mercuri F. Nanoscale morphology and electronic coupling at the interface between indium tin oxide and organic molecular materials. NANOSCALE 2018; 10:9376-9385. [PMID: 29738001 DOI: 10.1039/c8nr02341g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The correlation between nanoscale morphology and charge injection rates at the interface between an organic semiconductor layer and a transparent metal oxide electrode was investigated by integrating molecular dynamics simulations with electronic structure calculations. The simulation approach proposed has been applied to the analysis of the hole injection mechanism at the interface between an amorphous layer of tris[(3-phenyl-1H-benzimidazol-1-yl-2(3H)-ylidene)-1,2-phenylene]Ir (DPBIC), a hole transport and emitter molecule, and the surface of indium tin oxide (ITO), a material commonly used as anode in OLEDs. The link between interface morphology and charge injection was investigated by implementing a two-step, top-down simulation approach. Namely, nanoscale molecular aggregation phenomena at the organic/electrode interface were first assessed by molecular dynamics simulations, mimicking different processing conditions, and followed by density functional theory calculations of the electronic coupling between molecular levels and the manifold of electrode states involved in the charge injection process. The correlation between structural parameters and electronic coupling suggests a significant role of specific molecule/electrode configurations on charge transport processes at the interface, resulting in a broad distribution of charge injection rates, and highlights the link between molecular structure, nanoscale aggregation and processing in the realization of heterointerfaces for efficient charge injection in organic electronic devices.
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Affiliation(s)
- Andrea Lorenzoni
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN), Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, Italy.
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21
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Abstract
In this paper, we present our generalized kinetic Monte Carlo (kMC) framework for the simulation of organic semiconductors and electronic devices such as solar cells (OSCs) and light-emitting diodes (OLEDs). Our model generalizes the geometrical representation of the multifaceted properties of the organic material by the use of a non-cubic, generalized Voronoi tessellation and a model that connects sites to polymer chains. Herewith, we obtain a realistic model for both amorphous and crystalline domains of small molecules and polymers. Furthermore, we generalize the excitonic processes and include triplet exciton dynamics, which allows an enhanced investigation of OSCs and OLEDs. We outline the developed methods of our generalized kMC framework and give two exemplary studies of electrical and optical properties inside an organic semiconductor.
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22
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Machine learning of correlated dihedral potentials for atomistic molecular force fields. Sci Rep 2018; 8:2559. [PMID: 29416116 PMCID: PMC5803249 DOI: 10.1038/s41598-018-21070-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 01/19/2018] [Indexed: 11/14/2022] Open
Abstract
Computer simulation increasingly complements experimental efforts to describe nanoscale structure formation. Molecular mechanics simulations and related computational methods fundamentally rely on the accuracy of classical atomistic force fields for the evaluation of inter- and intramolecular energies. One indispensable component of such force fields, in particular for large organic molecules, is the accuracy of molecule-specific dihedral potentials which are the key determinants of molecular flexibility. We show in this work that non-local correlations of dihedral potentials play a decisive role in the description of the total molecular energy—an effect which is neglected in most state-of-the-art dihedral force fields. We furthermore present an efficient machine learning approach to compute intramolecular conformational energies. We demonstrate with the example of α-NPD, a molecule frequently used in organic electronics, that this approach outperforms traditional force fields by decreasing the mean absolute deviations by one order of magnitude to values smaller than 0.37 kcal/mol (16.0 meV) per dihedral angle.
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23
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Park JW, Lee KI, Choi YS, Kim JH, Jeong D, Kwon YN, Park JB, Ahn HY, Park JI, Lee HS, Shin J. The prediction of hole mobility in organic semiconductors and its calibration based on the grain-boundary effect. Phys Chem Chem Phys 2018; 18:21371-80. [PMID: 27425259 DOI: 10.1039/c6cp02993k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A new reliable computational model to predict the hole mobility of poly-crystalline organic semiconductors in thin films was developed. Site energy differences and transfer integrals in crystalline morphologies of organic molecules were obtained from quantum chemical calculations, in which periodic boundary conditions were efficiently applied to capture the interactions with the surrounding molecules in the crystalline organic layer. Then the parameters were employed in kinetic Monte Carlo (kMC) simulations to estimate the carrier mobility. Carrier transport in multiple directions has been considered in the kMC simulation to mimic poly-crystalline characteristics under thin-film conditions. Furthermore, the calculated mobility was corrected using a calibration equation based on microscopy images of the thin films to take the effect of grain boundaries into account. As a result, good agreement was observed between the predicted and measured hole mobility values for 21 molecular species: the coefficient of determination (R(2)) was estimated to be 0.83 and the mean absolute error was 1.32 cm(2) V(-1) s(-1). This numerical approach can be applied to any molecules for which crystal structures are available and will provide a rapid and precise way of predicting device performance.
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Affiliation(s)
- Jin Woo Park
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16678, Republic of Korea.
| | - Kyu Il Lee
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16678, Republic of Korea.
| | - Youn-Suk Choi
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16678, Republic of Korea.
| | - Jung-Hwa Kim
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16678, Republic of Korea.
| | - Daun Jeong
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16678, Republic of Korea.
| | - Young-Nam Kwon
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16678, Republic of Korea.
| | - Jong-Bong Park
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16678, Republic of Korea.
| | - Ho Young Ahn
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16678, Republic of Korea.
| | - Jeong-Il Park
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16678, Republic of Korea.
| | - Hyo Sug Lee
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16678, Republic of Korea.
| | - Jaikwang Shin
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16678, Republic of Korea.
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24
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Keum CM, Liu S, Al-Shadeedi A, Kaphle V, Callens MK, Han L, Neyts K, Zhao H, Gather MC, Bunge SD, Twieg RJ, Jakli A, Lüssem B. Tuning charge carrier transport and optical birefringence in liquid-crystalline thin films: A new design space for organic light-emitting diodes. Sci Rep 2018; 8:699. [PMID: 29335503 PMCID: PMC5768873 DOI: 10.1038/s41598-018-19157-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 12/12/2017] [Indexed: 11/09/2022] Open
Abstract
Liquid-crystalline organic semiconductors exhibit unique properties that make them highly interesting for organic optoelectronic applications. Their optical and electrical anisotropies and the possibility to control the alignment of the liquid-crystalline semiconductor allow not only to optimize charge carrier transport, but to tune the optical property of organic thin-film devices as well. In this study, the molecular orientation in a liquid-crystalline semiconductor film is tuned by a novel blading process as well as by different annealing protocols. The altered alignment is verified by cross-polarized optical microscopy and spectroscopic ellipsometry. It is shown that a change in alignment of the liquid-crystalline semiconductor improves charge transport in single charge carrier devices profoundly. Comparing the current-voltage characteristics of single charge carrier devices with simulations shows an excellent agreement and from this an in-depth understanding of single charge carrier transport in two-terminal devices is obtained. Finally, p-i-n type organic light-emitting diodes (OLEDs) compatible with vacuum processing techniques used in state-of-the-art OLEDs are demonstrated employing liquid-crystalline host matrix in the emission layer.
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Affiliation(s)
- Chang-Min Keum
- Department of Physics, Kent State University, Kent, OH, 44242, USA.
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom.
| | - Shiyi Liu
- Department of Physics, Kent State University, Kent, OH, 44242, USA
| | - Akram Al-Shadeedi
- Department of Physics, Kent State University, Kent, OH, 44242, USA
- Department of physics, University of Baghdad, Al-Jadriya, Baghdad, 10071, Iraq
| | - Vikash Kaphle
- Department of Physics, Kent State University, Kent, OH, 44242, USA
| | - Michiel Koen Callens
- Department of Electronics and Information Systems, Ghent University, Ghent, B-9000, Belgium
| | - Lu Han
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Kristiaan Neyts
- Department of Electronics and Information Systems, Ghent University, Ghent, B-9000, Belgium
| | - Hongping Zhao
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Malte C Gather
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom
| | - Scott D Bunge
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA
| | - Robert J Twieg
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA
| | - Antal Jakli
- Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
| | - Björn Lüssem
- Department of Physics, Kent State University, Kent, OH, 44242, USA
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25
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Rozycka A, Iwan A, Bogdanowicz KA, Filapek M, Górska N, Hreniak A, Marzec M. Structural and electrochemical studies of TiO2 complexes with (4,4′-((1E,1′E)-(2,5-bis(octyloxy)-1,4-phenylene)bis(ethene-2,1-diyl))bis-(E)-N-(2,5-bis(octyloxy)benzylidene)) imine derivative bases towards organic devices. Dalton Trans 2018; 47:7682-7693. [DOI: 10.1039/c8dt01418c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structural, thermal, optical, electrochemical and photovoltaic properties were investigated to check the influence of TiO2 on the imine properties.
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Affiliation(s)
- Anna Rozycka
- Institute of Physics
- Jagiellonian University
- 30-348 Krakow
- Poland
| | - Agnieszka Iwan
- General Tadeusz Kosciuszko Military University of Land Forces
- Wroclaw
- MULF Wroclaw
- Faculty of Security and Safety Research
- 51-147 Wroclaw
| | | | - Michal Filapek
- Institute of Chemistry
- University of Silesia
- 40-006 Katowice
- Poland
| | - Natalia Górska
- Faculty of Chemistry
- Jagiellonian University
- 30-387 Kraków
- Poland
| | - Agnieszka Hreniak
- Electrotechnical Institute
- Division of Electrotechnology and Materials Science
- 50-369 Wroclaw
- Poland
| | - Monika Marzec
- Institute of Physics
- Jagiellonian University
- 30-348 Krakow
- Poland
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26
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Milichko VA, Khramenkova EV, Dzyuba VP, Pidko EA. Response to Comment "On the Existence of Excitonic Signatures in the Optical Response of Metal-Organic Frameworks". ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1705261. [PMID: 29239521 DOI: 10.1002/adma.201705261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/14/2017] [Indexed: 06/07/2023]
Abstract
This is a response to a comment on the interpretation of the origin of the nonlinear changes of optical properties of van der Waals' metal-organic frameworks (MOFs). The concerns are addressed by clarifying potential pitfalls in density functional theory (DFT) simulations, careful analysis of prior literature, and additionally discussing the previous experimental results to emphasize the applicability of the excitonic concept in molecular crystals, such as MOFs.
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Affiliation(s)
- Valentin A Milichko
- Department of Nanophotonics and Metamaterials, ITMO University, St. Petersburg, 197101, Russia
| | - Elena V Khramenkova
- TheoMAT group, International Laboratory "Solution Chemistry of Advanced Materials and Technologies", ITMO University, St. Petersburg, 197101, Russia
| | - Vladimir P Dzyuba
- Institute of Automation and Control Processes FEB RAS, Vladivostok, 690041, Russia
| | - Evgeny A Pidko
- TheoMAT group, International Laboratory "Solution Chemistry of Advanced Materials and Technologies", ITMO University, St. Petersburg, 197101, Russia
- Inorganic Systems Engineering group, Department of Chemical Engineering, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ, Delft, The Netherlands
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27
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Peng C, Salehi A, Chen Y, Danz M, Liaptsis G, So F. Probing the Emission Zone Length in Organic Light Emitting Diodes via Photoluminescence and Electroluminescence Degradation Analysis. ACS APPLIED MATERIALS & INTERFACES 2017; 9:41421-41427. [PMID: 29090901 DOI: 10.1021/acsami.7b13537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The understanding and control of the emission zone in organic light emitting diodes (OLEDs) is crucial to the device operational stability. Using the photoluminescence and electroluminescence degradation data, we have developed a modeling methodology to quantitatively determine the length of the emission zone and correlate that with the degradation mechanism. We first validate the modeling results by studying the emitter concentration effect on operational stability of devices using the well-studied thermal activated delayed fluorescent (TADF) emitter (4s,6s)-2,4,5,6-tetra(9H-carbazol-9-yl)isophthalonitrile (4CzIPN), and our results are consistent with previous published data. We further applied this methodology to study the emitter concentration effect using another TADF emitter, 4-carbazolyl-2-methylisoindole-1,3-dione (dopant 1). The results show that the emission zone of the dopant 1 devices is narrower than the 4CzIPN device, leading to faster degradation. While a higher emitter concentration does not result in widening of the emission zone, we were able to widen the emission zone and hence extend the device lifetime using a mixed host.
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Affiliation(s)
- Cheng Peng
- Department of Materials Science and Engineering, University of Florida , Gainesville, Florida 32611, United States
| | | | | | - Michael Danz
- CYNORA, GmbH , Werner-von-Siemens-Straße 2-6, Building 5110, 76646 Bruchsal, Germany
| | - Georgios Liaptsis
- CYNORA, GmbH , Werner-von-Siemens-Straße 2-6, Building 5110, 76646 Bruchsal, Germany
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28
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Design rules for light-emitting electrochemical cells delivering bright luminance at 27.5 percent external quantum efficiency. Nat Commun 2017; 8:1190. [PMID: 29085078 PMCID: PMC5662711 DOI: 10.1038/s41467-017-01339-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 09/12/2017] [Indexed: 11/08/2022] Open
Abstract
The light-emitting electrochemical cell promises cost-efficient, large-area emissive applications, as its characteristic in-situ doping enables use of air-stabile electrodes and a solution-processed single-layer active material. However, mutual exclusion of high efficiency and high brightness has proven a seemingly fundamental problem. Here we present a generic approach that overcomes this critical issue, and report on devices equipped with air-stabile electrodes and outcoupling structure that deliver a record-high efficiency of 99.2 cd A-1 at a bright luminance of 1910 cd m-2. This device significantly outperforms the corresponding optimized organic light-emitting diode despite the latter employing calcium as the cathode. The key to this achievement is the design of the host-guest active material, in which tailored traps suppress exciton diffusion and quenching in the central recombination zone, allowing efficient triplet emission. Simultaneously, the traps do not significantly hamper electron and hole transport, as essentially all traps in the transport regions are filled by doping.
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29
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Felekidis N, Melianas A, Kemerink M. Design Rule for Improved Open-Circuit Voltage in Binary and Ternary Organic Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2017; 9:37070-37077. [PMID: 28967245 DOI: 10.1021/acsami.7b08276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Mixing different compounds to improve functionality is one of the pillars of the organic electronics field. Here, the degree to which the charge transport properties of the constituent materials are simply additive when materials are mixed is quantified. It is demonstrated that in bulk heterojunction organic solar cells, hole mobility in the donor phase depends critically on the choice of the acceptor material, which may alter the energetic disorder of the donor. The same holds for electron mobility and disorder in the acceptor. The associated mobility differences can exceed an order of magnitude compared to pristine materials. Quantifying these effects by a state-filling model for the open-circuit voltage (VOC) of ternary Donor:Acceptor1:Acceptor2 (D:A1:A2) organic solar cells leads to a physically transparent description of the surprising, nearly linear tunability of the VOC with the A1:A2 weight ratio. It is predicted that in binary OPV systems, suitably chosen donor and acceptor materials can improve the device power conversion efficiency (PCE) by several percentage points, for example from 11 to 13.5% for a hypothetical state-of-the-art organic solar cell, highlighting the importance of this design rule.
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Affiliation(s)
- Nikolaos Felekidis
- Complex Materials and Devices and ‡Biomolecular and Organic Electronics, Department of Physics, Chemistry and Biology (IFM), Linköping University , SE-581 83 Linköping, Sweden
| | - Armantas Melianas
- Complex Materials and Devices and ‡Biomolecular and Organic Electronics, Department of Physics, Chemistry and Biology (IFM), Linköping University , SE-581 83 Linköping, Sweden
| | - Martijn Kemerink
- Complex Materials and Devices and ‡Biomolecular and Organic Electronics, Department of Physics, Chemistry and Biology (IFM), Linköping University , SE-581 83 Linköping, Sweden
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30
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Li H, Brédas JL. Kinetic Monte Carlo Modeling of Charge Carriers in Organic Electronic Devices: Suppression of the Self-Interaction Error. J Phys Chem Lett 2017; 8:2507-2512. [PMID: 28520427 DOI: 10.1021/acs.jpclett.7b01161] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Kinetic Monte Carlo (KMC) simulations have emerged as an important tool to help improve the efficiency of organic electronic devices by providing a better understanding of their device physics. In the KMC simulation of an organic device, the reliability of the results depends critically on the accuracy of the chosen charge-transfer rates, which are themselves strongly influenced by the site-energy differences. These site-energy differences include components coming from the electrostatic forces present in the system, which are often evaluated through electric potentials described by the Poisson equation. Here we show that the charge-carrier self-interaction errors that appear when evaluating the site-energy differences can lead to unreliable simulation results. To eliminate these errors, we propose two approaches that are also found to reduce the impact of finite-size effects. As a consequence, reliable results can be obtained at reduced computational costs. The proposed methodologies can be extended to other device simulation techniques as well.
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Affiliation(s)
- Haoyuan Li
- Laboratory for Computational and Theoretical Chemistry of Advanced Materials, Physical Science and Engineering Division, King Abdullah University of Science and Technology , Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Jean-Luc Brédas
- Laboratory for Computational and Theoretical Chemistry of Advanced Materials, Physical Science and Engineering Division, King Abdullah University of Science and Technology , Thuwal 23955-6900, Kingdom of Saudi Arabia
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31
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Fathollahi M, Ameri M, Mohajerani E, Mehrparvar E, Babaei M. Organic/Organic Heterointerface Engineering to Boost Carrier Injection in OLEDs. Sci Rep 2017; 7:42787. [PMID: 28218246 PMCID: PMC5316975 DOI: 10.1038/srep42787] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 01/17/2017] [Indexed: 12/03/2022] Open
Abstract
We investigate dynamic formation of nanosheet charge accumulations by heterointerface engineering in double injection layer (DIL) based organic light emitting diodes (OLEDs). Our experimental results show that the device performance is considerably improved for the DIL device as the result of heterointerface injection layer (HIIL) formation, in comparison to reference devices, namely, the current density is doubled and even quadrupled and the turn-on voltage is favorably halved, to 3.7 V, which is promising for simple small-molecule OLEDs. The simulation reveals the (i) formation of dynamic p-type doping (DPD) region which treats the quasi Fermi level at the organic/electrode interface, and (ii) formation of dynamic dipole layer (DDL) and the associated electric field at the organic/organic interface which accelerates the ejection of the carriers and their transference to the successive layer. HIIL formation proposes alternate scenarios for device design. For instance, no prerequisite for plasma treatment of transparent anode electrode, our freedom in varying the thicknesses of the organic layers between 10 nm and 60 nm for the first layer and between 6 nm and 24 nm for the second layer. The implications of the present work give insight into the dynamic phenomena in OLEDs and facilitates the development of their inexpensive fabrication for lighting applications.
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Affiliation(s)
- Mohammadreza Fathollahi
- Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113, Iran
| | - Mohsen Ameri
- Department of Physics, Bu-Ali Sina University, P.O. Box 65174, Hamedan, Iran
| | - Ezeddin Mohajerani
- Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113, Iran
| | - Ebrahim Mehrparvar
- Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113, Iran
| | - Mohammadrasoul Babaei
- Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113, Iran
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32
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Groves C. Simulating charge transport in organic semiconductors and devices: a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:026502. [PMID: 27991440 DOI: 10.1088/1361-6633/80/2/026502] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Charge transport simulation can be a valuable tool to better understand, optimise and design organic transistors (OTFTs), photovoltaics (OPVs), and light-emitting diodes (OLEDs). This review presents an overview of common charge transport and device models; namely drift-diffusion, master equation, mesoscale kinetic Monte Carlo and quantum chemical Monte Carlo, and a discussion of the relative merits of each. This is followed by a review of the application of these models as applied to charge transport in organic semiconductors and devices, highlighting in particular the insights made possible by modelling. The review concludes with an outlook for charge transport modelling in organic electronics.
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Affiliation(s)
- C Groves
- Durham University, School of Engineering and Computing Sciences, South Road, Durham, DH1 3LE, UK
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33
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Symalla F, Friederich P, Massé A, Meded V, Coehoorn R, Bobbert P, Wenzel W. Charge Transport by Superexchange in Molecular Host-Guest Systems. PHYSICAL REVIEW LETTERS 2016; 117:276803. [PMID: 28084749 DOI: 10.1103/physrevlett.117.276803] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Indexed: 06/06/2023]
Abstract
Charge transport in disordered organic semiconductors is generally described as a result of incoherent hopping between localized states. In this work, we focus on multicomponent emissive host-guest layers as used in organic light-emitting diodes (OLEDs), and show using multiscale ab initio based modeling that charge transport can be significantly enhanced by the coherent process of molecular superexchange. Superexchange increases the rate of emitter-to-emitter hopping, in particular if the emitter molecules act as relatively deep trap states, and allows for percolation path formation in charge transport at low guest concentrations.
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Affiliation(s)
- Franz Symalla
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Hermann von Helmholtz-Platz 1,76344 Eggenstein-Leopoldshafen, Germany
| | - Pascal Friederich
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Hermann von Helmholtz-Platz 1,76344 Eggenstein-Leopoldshafen, Germany
| | - Andrea Massé
- Department of Applied Physics and Institute for Complex Molecular systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Velimir Meded
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Hermann von Helmholtz-Platz 1,76344 Eggenstein-Leopoldshafen, Germany
| | - Reinder Coehoorn
- Department of Applied Physics and Institute for Complex Molecular systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Peter Bobbert
- Department of Applied Physics and Institute for Complex Molecular systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Wolfgang Wenzel
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Hermann von Helmholtz-Platz 1,76344 Eggenstein-Leopoldshafen, Germany
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34
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Aghazada S, Huckaba AJ, Pertegas A, Babaei A, Grancini G, Zimmermann I, Bolink H, Nazeeruddin MK. Molecular Engineering of Iridium Blue Emitters Using Aryl N-Heterocyclic Carbene Ligands. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201600971] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Sadig Aghazada
- Group for Molecular Engineering of Functional Materials; Ecole Polytechnique Federale de Lausanne Valais Wallis; Rue de l'Indutrie 17 1950 Sion Valais Switzerland
| | - Aron J. Huckaba
- Group for Molecular Engineering of Functional Materials; Ecole Polytechnique Federale de Lausanne Valais Wallis; Rue de l'Indutrie 17 1950 Sion Valais Switzerland
| | - Antonio Pertegas
- Instituto de Ciencia Molecular; Universidad de Valencia; c/Catedrático J. Beltrán 2 46980 Paterna Spain
| | - Azin Babaei
- Instituto de Ciencia Molecular; Universidad de Valencia; c/Catedrático J. Beltrán 2 46980 Paterna Spain
| | - Giulia Grancini
- Instituto de Ciencia Molecular; Universidad de Valencia; c/Catedrático J. Beltrán 2 46980 Paterna Spain
| | - Iwan Zimmermann
- Group for Molecular Engineering of Functional Materials; Ecole Polytechnique Federale de Lausanne Valais Wallis; Rue de l'Indutrie 17 1950 Sion Valais Switzerland
| | - Henk Bolink
- Instituto de Ciencia Molecular; Universidad de Valencia; c/Catedrático J. Beltrán 2 46980 Paterna Spain
| | - Mohammad Khaja Nazeeruddin
- Group for Molecular Engineering of Functional Materials; Ecole Polytechnique Federale de Lausanne Valais Wallis; Rue de l'Indutrie 17 1950 Sion Valais Switzerland
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35
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Han TH, Choi MR, Jeon CW, Kim YH, Kwon SK, Lee TW. Ultrahigh-efficiency solution-processed simplified small-molecule organic light-emitting diodes using universal host materials. SCIENCE ADVANCES 2016; 2:e1601428. [PMID: 27819053 PMCID: PMC5091357 DOI: 10.1126/sciadv.1601428] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 09/27/2016] [Indexed: 05/06/2023]
Abstract
Although solution processing of small-molecule organic light-emitting diodes (OLEDs) has been considered as a promising alternative to standard vacuum deposition requiring high material and processing cost, the devices have suffered from low luminous efficiency and difficulty of multilayer solution processing. Therefore, high efficiency should be achieved in simple-structured small-molecule OLEDs fabricated using a solution process. We report very efficient solution-processed simple-structured small-molecule OLEDs that use novel universal electron-transporting host materials based on tetraphenylsilane with pyridine moieties. These materials have wide band gaps, high triplet energy levels, and good solution processabilities; they provide balanced charge transport in a mixed-host emitting layer. Orange-red (~97.5 cd/A, ~35.5% photons per electron), green (~101.5 cd/A, ~29.0% photons per electron), and white (~74.2 cd/A, ~28.5% photons per electron) phosphorescent OLEDs exhibited the highest recorded electroluminescent efficiencies of solution-processed OLEDs reported to date. We also demonstrate a solution-processed flexible solid-state lighting device as a potential application of our devices.
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Affiliation(s)
- Tae-Hee Han
- Department of Materials Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyungbuk 790-784, Republic of Korea
- Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Mi-Ri Choi
- Department of Materials Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyungbuk 790-784, Republic of Korea
| | - Chan-Woo Jeon
- Department of Chemistry and Research Institute of Natural Science, Gyeongsang National University, Gyeongnam, Republic of Korea
| | - Yun-Hi Kim
- Department of Chemistry and Research Institute of Natural Science, Gyeongsang National University, Gyeongnam, Republic of Korea
- Corresponding author. (T.-W.L.); (Y.-H.K.)
| | - Soon-Ki Kwon
- School of Materials Science and Engineering and Engineering Research Institute, Gyeongsang National University, Gyeongnam, Republic of Korea
| | - Tae-Woo Lee
- Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
- Corresponding author. (T.-W.L.); (Y.-H.K.)
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36
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Vij V, Bhalla V, Kumar M. Hexaarylbenzene: Evolution of Properties and Applications of Multitalented Scaffold. Chem Rev 2016; 116:9565-627. [DOI: 10.1021/acs.chemrev.6b00144] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Varun Vij
- Department of Chemistry,
UGC Centre for Advanced Studies, Guru Nanak Dev University, Amritsar, Punjab 143005, India
| | - Vandana Bhalla
- Department of Chemistry,
UGC Centre for Advanced Studies, Guru Nanak Dev University, Amritsar, Punjab 143005, India
| | - Manoj Kumar
- Department of Chemistry,
UGC Centre for Advanced Studies, Guru Nanak Dev University, Amritsar, Punjab 143005, India
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37
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Peng C, Liu S, Fu X, Pan Z, Chen Y, So F, Schanze KS. Corrugated Organic Light Emitting Diodes Using Low Tg Electron Transporting Materials. ACS APPLIED MATERIALS & INTERFACES 2016; 8:16192-16199. [PMID: 27245622 DOI: 10.1021/acsami.6b02669] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A corrugated organic light emitting diode (OLED) with enhanced light extraction is realized by incorporating a corrugated composite electron transport layer (ETL) consisting of two ETLs with different glass transition temperatures. The morphology of the corrugated structure is characterized with atomic force microscopy. The results show that the corrugation can be controlled by the layer thicknesses and annealing temperature. Compared with the control planar device, the corrugated OLED shows a more than 35% enhancement in current efficiency from 31 cd/A to 43 cd/A and a 20% enhancement in external quantum efficiency from 10% to 12% at 100 cd/m(2). In addition, the corrugated OLED also has a greatly improved operational stability. The LT90 lifetime of a device operated at 1000 cd/m(2) is improved greater than 100-fold in the corrugated OLED.
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Affiliation(s)
- Cheng Peng
- Department of Materials Science and Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States
| | - Shuyi Liu
- Department of Materials Science and Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States
| | - Xiangyu Fu
- Department of Materials Science and Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States
| | | | - Ying Chen
- Department of Materials Science and Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States
| | - Franky So
- Department of Materials Science and Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States
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38
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Zhang L, van Eersel H, Bobbert P, Coehoorn R. Clarifying the mechanism of triplet–triplet annihilation in phosphorescent organic host–guest systems: A combined experimental and simulation study. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.04.043] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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39
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Friederich P, Symalla F, Meded V, Neumann T, Wenzel W. Ab Initio Treatment of Disorder Effects in Amorphous Organic Materials: Toward Parameter Free Materials Simulation. J Chem Theory Comput 2015; 10:3720-5. [PMID: 26588517 DOI: 10.1021/ct500418f] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Disordered organic materials have a wide range of interesting applications, such as organic light emitting diodes, organic photovoltaics, and thin film electronics. To model electronic transport through such materials it is essential to describe the energy distribution of the available electronic states of the carriers in the material. Here, we present a self-consistent, linear-scaling first-principles approach to model environmental effects on the electronic properties of disordered molecular systems. We apply our parameter free approach to calculate the energy disorder distribution of localized charge states in a full polaron model for two widely used benchmark-systems (tris(8-hydroxyquinolinato)aluminum (Alq3) and N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD)) and accurately reproduce the experimental charge carrier mobility over a range of 4 orders of magnitude. The method can be generalized to determine electronic and optical properties of more complex systems, e.g. guest-host morphologies, organic-organic interfaces, and thus offers the potential to significantly contribute to de novo materials design.
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Affiliation(s)
- Pascal Friederich
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT) , Karlsruhe 76021, Germany
| | - Franz Symalla
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT) , Karlsruhe 76021, Germany
| | - Velimir Meded
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT) , Karlsruhe 76021, Germany
| | - Tobias Neumann
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT) , Karlsruhe 76021, Germany
| | - Wolfgang Wenzel
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT) , Karlsruhe 76021, Germany
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40
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Oehzelt M, Akaike K, Koch N, Heimel G. Energy-level alignment at organic heterointerfaces. SCIENCE ADVANCES 2015; 1:e1501127. [PMID: 26702447 PMCID: PMC4681341 DOI: 10.1126/sciadv.1501127] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 10/18/2015] [Indexed: 05/17/2023]
Abstract
Today's champion organic (opto-)electronic devices comprise an ever-increasing number of different organic-semiconductor layers. The functionality of these complex heterostructures largely derives from the relative alignment of the frontier molecular-orbital energies in each layer with respect to those in all others. Despite the technological relevance of the energy-level alignment at organic heterointerfaces, and despite continued scientific interest, a reliable model that can quantitatively predict the full range of phenomena observed at such interfaces is notably absent. We identify the limitations of previous attempts to formulate such a model and highlight inconsistencies in the interpretation of the experimental data they were based on. We then develop a theoretical framework, which we demonstrate to accurately reproduce experiment. Applying this theory, a comprehensive overview of all possible energy-level alignment scenarios that can be encountered at organic heterojunctions is finally given. These results will help focus future efforts on developing functional organic interfaces for superior device performance.
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Affiliation(s)
- Martin Oehzelt
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Bereich Solarenergieforschung, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Institut für Physik, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
- Corresponding author. E-mail:
| | - Kouki Akaike
- Institut für Physik, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
| | - Norbert Koch
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Bereich Solarenergieforschung, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Institut für Physik, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
| | - Georg Heimel
- Institut für Physik, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
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41
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Park MH, Kim JY, Han TH, Kim TS, Kim H, Lee TW. Flexible Lamination Encapsulation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:4308-14. [PMID: 26102425 DOI: 10.1002/adma.201501856] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Revised: 05/16/2015] [Indexed: 05/14/2023]
Abstract
A novel flexible encapsulation method (Flex Lami-capsulation) is reported, which can be applied in the roll-to-roll process for mass production of organic electronic devices. Flex Lami-capsulation is very simple, fast, and getter-free, and is as effective as glass encapsulation. Use of this method is feasible in large-area flexible displays and does not have the drawbacks of conventional encapsulation methods.
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Affiliation(s)
- Min-Ho Park
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-gu, Pohang, Gyungbuk, 790-784, Republic of Korea
| | - Jin-You Kim
- POSCO 1 Goedong-dong, Nam-gu, Pohang, P.O. Box 36, Gyungbuk, 790-300, Republic of Korea
| | - Tae-Hee Han
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-gu, Pohang, Gyungbuk, 790-784, Republic of Korea
| | - Tae-Sik Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-gu, Pohang, Gyungbuk, 790-784, Republic of Korea
| | - Hobeom Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-gu, Pohang, Gyungbuk, 790-784, Republic of Korea
| | - Tae-Woo Lee
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-gu, Pohang, Gyungbuk, 790-784, Republic of Korea
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42
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Scholz S, Kondakov D, Lüssem B, Leo K. Degradation Mechanisms and Reactions in Organic Light-Emitting Devices. Chem Rev 2015; 115:8449-503. [DOI: 10.1021/cr400704v] [Citation(s) in RCA: 418] [Impact Index Per Article: 46.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Sebastian Scholz
- Institut
für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Strasse 1, 01069 Dresden, Germany
- Fraunhofer-Institut für Photonische Mikrosysteme, Maria-Reiche-Strasse 2, 01199 Dresden, Germany
| | - Denis Kondakov
- DuPont Displays Inc., 4417 Lancaster
Pike, Wilmington, Delaware 19805, United States
| | - Björn Lüssem
- Institut
für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Strasse 1, 01069 Dresden, Germany
| | - Karl Leo
- Institut
für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Strasse 1, 01069 Dresden, Germany
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43
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Moral M, Son WJ, Sancho-García JC, Olivier Y, Muccioli L. Cost-Effective Force Field Tailored for Solid-Phase Simulations of OLED Materials. J Chem Theory Comput 2015; 11:3383-92. [DOI: 10.1021/acs.jctc.5b00164] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M. Moral
- Departamento
de Química Física, Universidad de Alicante, 03080 Alicante, Spain
| | - W.-J. Son
- Samsung Advanced Institute of Technology, Suwon, 443-803 Gyeonggi-do, South Korea
| | - J. C. Sancho-García
- Departamento
de Química Física, Universidad de Alicante, 03080 Alicante, Spain
| | - Y. Olivier
- Laboratory
for Chemistry of Novel Materials, University of Mons, 7000 Mons, Belgium
| | - L. Muccioli
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, 40136 Bologna, Italy
- Laboratoire
de Chimie des Polymères Organiques (LCPO), UMR 5629, University of Bordeaux, 33607 Pessac, France
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44
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Friederich P, Meded V, Symalla F, Elstner M, Wenzel W. QM/QM approach to model energy disorder in amorphous organic semiconductors. J Chem Theory Comput 2015; 11:560-7. [PMID: 26580913 DOI: 10.1021/ct501023n] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is an outstanding challenge to model the electronic properties of organic amorphous materials utilized in organic electronics. Computation of the charge carrier mobility is a challenging problem as it requires integration of morphological and electronic degrees of freedom in a coherent methodology and depends strongly on the distribution of polaron energies in the system. Here we represent a QM/QM model to compute the polaron energies combining density functional methods for molecules in the vicinity of the polaron with computationally efficient density functional based tight binding methods in the rest of the environment. For seven widely used amorphous organic semiconductor materials, we show that the calculations are accelerated up to 1 order of magnitude without any loss in accuracy. Considering that the quantum chemical step is the efficiency bottleneck of a workflow to model the carrier mobility, these results are an important step toward accurate and efficient disordered organic semiconductors simulations, a prerequisite for accelerated materials screening and consequent component optimization in the organic electronics industry.
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Affiliation(s)
- Pascal Friederich
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (INT) , Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Velimir Meded
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (INT) , Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Franz Symalla
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (INT) , Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Marcus Elstner
- Institute of Physical Chemistry (IPC), Karlsruhe Institute of Technology (KIT) , Kaiserstraße 12, 76131 Karlsruhe, Germany
| | - Wolfgang Wenzel
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (INT) , Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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45
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Lorenzoni A, Muccini M, Mercuri F. Correlation between gate-dielectric morphology at the nanoscale and charge transport properties in organic field-effect transistors. RSC Adv 2015. [DOI: 10.1039/c4ra10954f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Initial preparation, thermal treatment, and microscopic structure of gate dielectric polymer materials impact on the transport properties of organic field-effect transistors, as revealed by an integrated computational approach.
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Affiliation(s)
- Andrea Lorenzoni
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN)
- Consiglio Nazionale delle Ricerche (CNR)
- 40129 Bologna
- Italy
| | - Michele Muccini
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN)
- Consiglio Nazionale delle Ricerche (CNR)
- 40129 Bologna
- Italy
| | - Francesco Mercuri
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN)
- Consiglio Nazionale delle Ricerche (CNR)
- 40129 Bologna
- Italy
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46
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Mendels D, Tessler N. Thermoelectricity in Disordered Organic Semiconductors under the Premise of the Gaussian Disorder Model and Its Variants. J Phys Chem Lett 2014; 5:3247-3253. [PMID: 26276340 DOI: 10.1021/jz5016058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Using Monte Carlo simulations, we investigate the thermoelectric properties of disordered organic semiconductors under the premise of the Gaussian disorder model and its variants. In doing so, we provide much needed additional dimensions for comparison between these theoretical frameworks and real systems beyond those based on extensively studied charge-transport properties and aim to provide a frame-of-reference for rising interest in these systems for thermoelectric-based applications. To illustrate the potential existing in the implementation of combined transport and thermoelectric investigation, we discuss strategies to experimentally deduce a system's DOS shape and the temperature dependence of its transport energy (which can discern hopping transport from multiple trapping transport), infer whether a system's activation energy originates from inherent energetic disorder or a polaron activation energy (while deducing the given polaron activation energy), and discerning whether a system's energetic disorder is spatially correlated or accompanied by off-diagonal disorder.
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Affiliation(s)
- Dan Mendels
- The Sarah and Moshe Zisapel Nanoelectronic Center, Electrical Engineering Department, Technion Israel Institute of Technology, Haifa 32000, Israel
| | - Nir Tessler
- The Sarah and Moshe Zisapel Nanoelectronic Center, Electrical Engineering Department, Technion Israel Institute of Technology, Haifa 32000, Israel
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47
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Massé A, Coehoorn R, Bobbert PA. Universal size-dependent conductance fluctuations in disordered organic semiconductors. PHYSICAL REVIEW LETTERS 2014; 113:116604. [PMID: 25259995 DOI: 10.1103/physrevlett.113.116604] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Indexed: 06/03/2023]
Abstract
Numerically exact results of hopping charge transport in disordered organic semiconductors show for uncorrelated and dipole-correlated Gaussian energy disorder a universal, power-law, and non-power-law dependence, respectively, of the relative conductance fluctuations on the size of the considered region. Data collapse occurs upon scaling with a characteristic length having a power-law temperature dependence. Below this length, which can be as high as 100 nm for correlated disorder in a realistic case, fluctuations dominate and a continuum description of charge transport breaks down.
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Affiliation(s)
- A Massé
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
| | - R Coehoorn
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands and Philips Research Laboratories, High Tech Campus 4, 5656 AE Eindhoven, Netherlands
| | - P A Bobbert
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
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48
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Kroese DP, Brereton T, Taimre T, Botev ZI. Why the Monte Carlo method is so important today. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/wics.1314] [Citation(s) in RCA: 289] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Dirk P. Kroese
- School of Mathematics and Physics The University of Queensland Brisbane Queensland Australia
| | - Tim Brereton
- Institute for Stochastics Ulm University Ulm Baden‐Württemburg Germany
| | - Thomas Taimre
- School of Mathematics and Physics The University of Queensland Brisbane Queensland Australia
| | - Zdravko I. Botev
- School of Mathematics and Statistics The University of New South Wales Sydney New South Wales Australia
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49
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Adachi T, Vogelsang J, Lupton JM. Unraveling the Electronic Heterogeneity of Charge Traps in Conjugated Polymers by Single-Molecule Spectroscopy. J Phys Chem Lett 2014; 5:573-577. [PMID: 26276611 DOI: 10.1021/jz402621y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Charge trapping is taken for granted in modeling the characteristics of organic semiconductor devices, but very few techniques actually exist to spectroscopically pinpoint trap states. For example, trap levels are often assumed to be discrete in energy. Using the well-known keto defect in polyfluorene as a model, we demonstrate how single-molecule spectroscopy can directly track the formation of charge and exciton traps in conjugated polymers in real time, providing crucial information on the energetic distribution of trap sites relative to the polymer optical gap. Charge traps with universal spectral fingerprints scatter by almost 1 eV in depth, implying that substantial heterogeneity must be taken into account when modeling devices.
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Affiliation(s)
- Takuji Adachi
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Jan Vogelsang
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - John M Lupton
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
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50
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Fornari RP, Troisi A. Theory of charge hopping along a disordered polymer chain. Phys Chem Chem Phys 2014; 16:9997-10007. [DOI: 10.1039/c3cp54661f] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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