1
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Andrikopoulos KC, Tselekidou D, Anastasopoulos C, Papadopoulos K, Kyriazopoulos V, Logothetidis S, Kallitsis JK, Gioti M, Andreopoulou AK. Fluorescent Aromatic Polyether Sulfones: Processable, Scalable, Efficient, and Stable Polymer Emitters and Their Single-Layer Polymer Light-Emitting Diodes. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:1246. [PMID: 39120351 PMCID: PMC11313940 DOI: 10.3390/nano14151246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/12/2024] [Accepted: 07/15/2024] [Indexed: 08/10/2024]
Abstract
In this study, fully aromatic polyether sulfones were developed, bearing blue, yellow, and orange-red π-conjugated semiconducting units. Carbazole-, anthracene-, and benzothiadiazole-based fluorophores are copolymerized with a diphenylsulfone moiety. A diphenylpyridine comonomer was additionally utilized, acting as both a solubilizing unit and a weak blue fluorescent group. Using this rationale, fluorescent polyarylethers with high molecular weights, up to 70 kDa, were developed, showing film formation ability and high thermal stability, while preserving excellent solubility in common organic, nonvolatile, and nonchlorinated solvents. Fine-tuning of the emission color was achieved through subtle changes of the comonomers' type and ratio. Single-chromophore-bearing copolymers emitted in the blue or the yellow region of the visible spectrum, while the dual-chromophore-bearing terpolymers emitted throughout the visible spectrum, resulting in white light emission. Solutions of 20 wt% in polar aprotic solvents at ambient conditions allowed the deposition of fluorescent copolyethers and printing from non-chlorinated solvents. All polyethers were evaluated for their structural and optoelectronic properties, and selected copolymers were successfully used in the emitting layer (EML) of organic light-emitting diode (OLED) devices, using either rigid or flexible substrates. Remarkable color stability was displayed in all cases for up to 15 V of bias voltage. The Commission Internationale de L'Eclairage (CIE) of the fabricated devices is located in the blue (0.16, 0.16), yellow (0.44, 0.50), or white region of the visible spectrum (0.33, 0.38) with minimal changes according to the ratio of the comonomers. The versatile methodology toward semiconducting polyethersulfones for polymer light-emitting diodes (PLEDs) developed herein led to the scaled-up production of luminescent polymers of up to 25 g of high-molecular-weight single batches, demonstrating the effectiveness of this approach as a straightforward tool to facilitate the synthesis of flexible and printable EMLs for large-area PLED coverage.
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Affiliation(s)
| | - Despoina Tselekidou
- Nanotechnology Laboratory LTFN, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (D.T.); (S.L.)
| | | | - Kyparisis Papadopoulos
- Nanotechnology Laboratory LTFN, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (D.T.); (S.L.)
| | - Vasileios Kyriazopoulos
- Organic Electronic Technologies P.C. (OET), 20th KM Thessaloniki—Tagarades, 57001 Thermi, Greece
| | - Stergios Logothetidis
- Nanotechnology Laboratory LTFN, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (D.T.); (S.L.)
- Organic Electronic Technologies P.C. (OET), 20th KM Thessaloniki—Tagarades, 57001 Thermi, Greece
| | - Joannis K. Kallitsis
- Department of Chemistry, University of Patras, University Campus, 26504 Rio-Patras, Greece (C.A.)
- Foundation for Research and Technology Hellas/Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Platani Str., 26504 Patras, Greece
| | - Maria Gioti
- Nanotechnology Laboratory LTFN, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (D.T.); (S.L.)
| | - Aikaterini K. Andreopoulou
- Department of Chemistry, University of Patras, University Campus, 26504 Rio-Patras, Greece (C.A.)
- Foundation for Research and Technology Hellas/Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Platani Str., 26504 Patras, Greece
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2
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Neu YC, Lin YS, Weng YH, Chen WC, Liu CL, Lin BH, Lin YC, Chen WC. Reversible Molecular Conformation Transitions of Smectic Liquid Crystals for Light/Bias-Gated Transistor Memory. ACS APPLIED MATERIALS & INTERFACES 2024; 16:7500-7511. [PMID: 38300744 PMCID: PMC10875644 DOI: 10.1021/acsami.3c16882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 02/03/2024]
Abstract
In recent years, organic photonic field-effect transistors have made remarkable progress with the rapid development of conjugated polycrystalline materials. Liquid crystals, with their smooth surface, defined layer thickness, and crystalline structures, are commonly used for these advantages. In this work, a series of smectic liquid crystalline molecules, 2,9-didecyl-dinaphtho-thienothiophene (C10-DNTT), 2,7-didecyl-benzothieno-benzothiopene (C10-BTBT), 3,9-didecyl-dinaphtho-thiophene (C10-DNT), and didecyl-sexithiophene (C10-6T), have been used in photonic transistor memory, functioning as both hole-transport channels and electron traps to investigate systematically the reasons and mechanisms behind the memory behavior of smectic liquid crystals. After thermal annealing, C10-BTBT and C10-6T/C10-DNTT are homeotropically aligned from the smectic A and smectic X phases, respectively. The 3D-ordered structure of these smectic-aligned crystals contributed to efficient photowriting and electrical erasing processes. Among them, the device performance of C10-BTBT was particularly significant, with a memory window of 21 V. The memory ratio could reach 1.5 × 106 and maintain a memory ratio of over 3 orders after 10,000 s, contributing to its smectic A structure. Through the research, we confirmed the memory and light/bias-gated behaviors of these smectic liquid crystalline molecules, attributing them to reversible molecular conformation transitions and the inherent structural inhomogeneity inside the polycrystalline channel layer.
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Affiliation(s)
- Yi-Chieh Neu
- Department
of Chemical Engineering, National Taiwan
University, Taipei 10617, Taiwan
| | - Yi-Sa Lin
- Department
of Chemical Engineering, National Taiwan
University, Taipei 10617, Taiwan
| | - Yi-Hsun Weng
- Department
of Chemical Engineering, National Taiwan
University, Taipei 10617, Taiwan
| | - Wei-Cheng Chen
- Department
of Chemical Engineering, National Taiwan
University, Taipei 10617, Taiwan
| | - Cheng-Liang Liu
- Department
of Materials Science and Engineering, National
Taiwan University, Taipei 10617, Taiwan
- Advanced
Research Center for Green Materials Science and Technology, National Taiwan University, Taipei 10617, Taiwan
| | - Bi-Hsuan Lin
- National
Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Yan-Cheng Lin
- Advanced
Research Center for Green Materials Science and Technology, National Taiwan University, Taipei 10617, Taiwan
- Department
of Chemical Engineering, National Cheng
Kung University, Tainan 70101, Taiwan
| | - Wen-Chang Chen
- Department
of Chemical Engineering, National Taiwan
University, Taipei 10617, Taiwan
- Advanced
Research Center for Green Materials Science and Technology, National Taiwan University, Taipei 10617, Taiwan
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3
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Zhao H, Cheng X. Fluorene Thiophene α-Cyanostilbene Hexacatenar-Generating LCs with Hexagonal Columnar Phases and Gels with Helical Morphologies as Well as a Light-Emitting LC Display. Int J Mol Sci 2023; 24:ijms24119337. [PMID: 37298292 DOI: 10.3390/ijms24119337] [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: 04/30/2023] [Revised: 05/20/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
Two series of novel synthesized hexacatenars, O/n and M/n, containing two thiophene-cyanostilbene units interconnected by central fluorene units (fluorenone or dicyanovinyl fluorene) using a donor-acceptor-acceptor-donor (A-D-A-D-A) rigid core, with three alkoxy chains at each end, can self-assemble into hexagonal columnar mesophases with wide liquid crystal (LC) ranges and aggregate into organogels with flowerlike and helical cylinder morphologies, as revealed via POM, DSC, XRD and SEM investigation. Furthermore, these compounds were observed to emit yellow luminescence in both solution and solid states which can be adopted to manufacture a light-emitting liquid crystal display (LE-LCD) by doping with commercially available nematic LC.
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Affiliation(s)
- Hongmei Zhao
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Research & Development Center for Natural Products, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
- School of Science, Yunnan Agricultural University, Kunming 650201, China
| | - Xiaohong Cheng
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Research & Development Center for Natural Products, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
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4
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Chatterjee D, Huang S, Gu K, Ju J, Yu J, Bock H, Yu L, Ediger MD, Voyles PM. Using 4D STEM to Probe Mesoscale Order in Molecular Glass Films Prepared by Physical Vapor Deposition. NANO LETTERS 2023; 23:2009-2015. [PMID: 36799489 DOI: 10.1021/acs.nanolett.3c00197] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Physical vapor deposition can be used to prepare highly stable organic glass systems where the molecules show orientational and translational ordering at the nanoscale. We have used low-dose four-dimensional scanning transmission electron microscopy (4D STEM), enabled by a fast direct electron detector, to map columnar order in glassy samples of a discotic mesogen using a 2 nm probe. Both vapor-deposited and liquid-cooled glassy films show domains of similar orientation, but their size varies from tens to hundreds of nanometers, depending on processing. Domain sizes are consistent with surface-diffusion-mediated ordering during film deposition. These results demonstrate the ability of low-dose 4D STEM to characterize a mesoscale structure in a molecular glass system which may be relevant to organic electronics.
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Affiliation(s)
- Debaditya Chatterjee
- Department of Materials Science and Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
- Applied Materials Inc., Santa Clara, California, 95054 United States
| | - Shuoyuan Huang
- Department of Materials Science and Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Kaichen Gu
- Department of Chemistry, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Jianzhu Ju
- Department of Chemistry, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Junguang Yu
- School of Pharmacy, University of Wisconsin─Madison, Madison, Wisconsin 53705, United States
| | - Harald Bock
- Centre de Recherche Paul Pascal-CNRS & Université de Bordeaux, 33600 Pessac, France
| | - Lian Yu
- School of Pharmacy, University of Wisconsin─Madison, Madison, Wisconsin 53705, United States
| | - M D Ediger
- Department of Chemistry, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Paul M Voyles
- Department of Materials Science and Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
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5
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Huang KC, Chen JY, Lin YH, Juang FS, Tsai YS. Lifetime Comparisons of Organic Light-Emitting Diodes Fabricated by Solution and Evaporation Processes. MICROMACHINES 2023; 14:278. [PMID: 36837978 PMCID: PMC9967824 DOI: 10.3390/mi14020278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
In this paper, a blue fluorescent organic light-emitting diode (OLED) with a 1 cm2 emitting area was fabricated by a solution process. The ITO/spin MADN:13% UBD-07/TPBi/Al was used as the basic structure in which to add a hole-injection layer PEDOT:PSS and an electron-injection layer LiF, respectively. The device structure was optimized to obtain a longer lifetime. Firstly, the TPBi, which is an electron transport layer and a hole-blocking layer, was added to the structure to increase the electron transport rate. When the TPBi thickness was increased to 20 nm, the luminance was 221 cd/m2, and the efficiency was 0.52 cd/A at a voltage of 8 V. Since the addition of the hole-injection layer (HIL) increased the hole current but did not increase the electron current, the electron transport layer (ETL) Alq3 with the lowest unoccupied molecular orbital (LUMO) was added as stepped ETL to help the TPBi transport more electron current into the emitting layer. When the thickness of the TPBi/Alq3 was 10 nm/15 nm, the luminance reached 862 cd/m2, the efficiency was 1.29 cd/A, and the lifetime increased to 252 min. Subsequently, a hole-injection layer PEDOT:PSS with a thickness of 55 nm was added to make the ITO surface flatter and to reduce the probability of a short circuit caused by the spike effect. At this time, the luminance of 311 cd/m2, the efficiency of 0.64 cd/A, and the lifetime of 121 min were obtained. Following this, the thickness of the emitting layer was doubled to increase the recombination probability of the electrons and the holes. When the thickness of the emitting layer was 90 nm, and the thermal evaporation method was used, the efficiency was 3.23 cd/A at a voltage of 8V, and the lifetime was improved to 482 min. Furthermore, when the thickness of the hole-injection layer PEDOT:PSS was increased to 220 nm, the efficiency increased to 3.86 cd/A, and the lifetime was increased to 529 min. An infrared thermal image camera was employed to detect the temperature variation of the blue OLEDs. After the current was gradually increased, it was found that the heat accumulation of the device became more and more significant. When the driving current reached 50 mA, the device burnt out. It was found that the maximum temperature that the OLED device could withstand was approximately 58.83 degrees C at a current of 36.36 mA.
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Affiliation(s)
- Kuo-Chun Huang
- Department of Electro-Optical Engineering, National Formosa University, Huwei, Yunlin 632-08, Taiwan
| | - Jeng-Yue Chen
- Department of Electrical Engineering, National Formosa University, Huwei, Yunlin 632-08, Taiwan
| | - Yen-Hua Lin
- Department of Electro-Optical Engineering, National Formosa University, Huwei, Yunlin 632-08, Taiwan
| | - Fuh-Shyang Juang
- Department of Electro-Optical Engineering, National Formosa University, Huwei, Yunlin 632-08, Taiwan
| | - Yu-Sheng Tsai
- Department of Electro-Optical Engineering, National Formosa University, Huwei, Yunlin 632-08, Taiwan
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Chen S, Ma T, Du X, Mo M, Wang Z, Cheng X. D-A-D hexacatenar LCs containing bulky N-trialkoxylbenzyl carbazole caps with RGB emissions for full color palette and white LED applications. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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7
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Balzer F, Breuer T, Witte G, Schiek M. Template and Temperature-Controlled Polymorph Formation in Squaraine Thin Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:9266-9277. [PMID: 35858043 PMCID: PMC9352357 DOI: 10.1021/acs.langmuir.2c01023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/06/2022] [Indexed: 06/15/2023]
Abstract
Controlling the polymorph formation in organic semiconductor thin films by the choice of processing parameters is a key factor for targeted device performance. Small molecular semiconductors such as the prototypical anilino squaraine compound with branched butyl chains as terminal functionalization (SQIB) allow both solution and vapor phase deposition methods. SQIB has been considered for various photovoltaic applications mainly as amorphous isotropic thin films due to its broad absorption within the visible to deep-red spectral range. The two known crystalline polymorphs adopting a monoclinic and orthorhombic crystal phase show characteristic Frenkel excitonic spectral signatures of overall H-type and J-type aggregates, respectively, with additional pronounced Davydov splitting. This gives a recognizable polarized optical response of crystalline thin films suitable for identification of the polymorphs. Both phases emerge with a strongly preferred out-of-plane and rather random in-plane orientation in spin-casted thin films depending on subsequent thermal annealing. By contrast, upon vapor deposition on dielectric and conductive substrates, such as silicon dioxide, potassium chloride, graphene, and gold, the polymorph expression depends basically on the choice of growth substrate. The same pronounced out-of-plane orientation is adopted in all crystalline cases, but with a surface templated in-plane alignment in case of crystalline substrates. Strikingly, the amorphous isotropic thin films obtained by vapor deposition cannot be crystallized by thermal postannealing, which is a key feature for the spin-casted thin films, here monitored by polarized in situ microscopy. Combining X-ray diffraction, atomic force microscopy, ellipsometry, and polarized spectro-microscopy, we identify the processing-dependent evolution of the crystal phases, correlating morphology and molecular orientations within the textured SQIB films.
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Affiliation(s)
- Frank Balzer
- SDU
Centre for Photonics Engineering, University
of Southern Denmark, Sønderborg DK-6400, Denmark
| | - Tobias Breuer
- Department
of Physics, Philipps University of Marburg, Marburg D-35032, Germany
| | - Gregor Witte
- Department
of Physics, Philipps University of Marburg, Marburg D-35032, Germany
| | - Manuela Schiek
- Institute
of Physics, University of Oldenburg, Oldenburg D-26111, Germany
- Center
for Surface- and Nanoanalytics (ZONA), Institute for Physical Chemistry
(IPC) & Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University, Linz A-4040, Austria
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8
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Franca LG, dos Santos PL, Pander P, Cabral MB, Cristiano R, Cazati T, Monkman AP, Bock H, Eccher J. Delayed Fluorescence by Triplet-Triplet Annihilation from Columnar Liquid Crystal Films. ACS APPLIED ELECTRONIC MATERIALS 2022; 4:3486-3494. [PMID: 35910938 PMCID: PMC9330766 DOI: 10.1021/acsaelm.2c00432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Delayed fluorescence (DF) by triplet-triplet annihilation (TTA) is observed in solutions of a benzoperylene-imidoester mesogen that shows a hexagonal columnar mesophase at room temperature in the neat state. A similar benzoperylene-imide with a slightly smaller HOMO-LUMO gap, that also is hexagonal columnar liquid crystalline at room temperature, does not show DF in solution, and mixtures of the two mesogens show no DF in solution either, because of collisional quenching of the excited triplet states on the imidoester by the imide. In contrast, DF by TTA from the imide but not from the imidoester is observed in condensed films of such mixtures, even though neat films of either single material are not displaying DF. In contrast to the DF from the monomeric imidoester in solution, DF of the imide occurs from dimeric aggregates in the blend films, assisted by the imidoester. Thus, the close contact of intimately stacked molecules of the two different species in the columnar mesophase leads to a unique mesophase-assisted aggregate DF. This constitutes the first observation of DF by TTA from the columnar liquid crystalline state. If the imide is dispersed in films of polybromostyrene, which provides an external heavy-atom effect facilitating triplet formation, DF is also observed. Organic light-emitting diodes (OLEDs) devices incorporating these liquid crystal molecules demonstrated high external quantum efficiency (EQE). On the basis of the literature and to the best of our knowledge, the EQE reported is the highest among nondoped solution-processed OLED devices using a columnar liquid crystal molecule as the emitting layer.
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Affiliation(s)
- Larissa G. Franca
- Department
of Physics, Durham University, South Road, Durham, DH1 3LE, United
Kingdom
- Departamento
de Física, Universidade Federal de
Santa Catarina, 88040900, Florianópolis, Santa Catarina, Brazil
| | - Paloma L. dos Santos
- Department
of Physics, Durham University, South Road, Durham, DH1 3LE, United
Kingdom
| | - Piotr Pander
- Department
of Physics, Durham University, South Road, Durham, DH1 3LE, United
Kingdom
- Faculty
of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice, Poland
| | - Marília
G. B. Cabral
- Departamento
de Química, Universidade Federal
da Paraíba, CEP 58051-900, João Pessoa, Paraíba, Brazil
- Centre
de Recherche Paul-Pascal, CNRS & Université
de Bordeaux, 33600, Pessac, France
| | - Rodrigo Cristiano
- Departamento
de Química, Universidade Federal
da Paraíba, CEP 58051-900, João Pessoa, Paraíba, Brazil
| | - Thiago Cazati
- Departamento
de Física, Universidade Federal de
Ouro Preto − UFOP, 35400-000, Ouro Preto, Minas
Gerais, Brazil
| | - Andrew P. Monkman
- Department
of Physics, Durham University, South Road, Durham, DH1 3LE, United
Kingdom
| | - Harald Bock
- Centre
de Recherche Paul-Pascal, CNRS & Université
de Bordeaux, 33600, Pessac, France
| | - Juliana Eccher
- Departamento
de Física, Universidade Federal de
Santa Catarina, 88040900, Florianópolis, Santa Catarina, Brazil
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9
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Unni AB, Winkler R, Duarte DM, Tu W, Chat K, Adrjanowicz K. Vapor-Deposited Thin Films: Studying Crystallization and α-relaxation Dynamics of the Molecular Drug Celecoxib. J Phys Chem B 2022; 126:3789-3798. [PMID: 35580265 PMCID: PMC9150116 DOI: 10.1021/acs.jpcb.2c01284] [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] [Indexed: 12/13/2022]
Abstract
Crystallization is one of the major challenges in using glassy solids for technological applications. Considering pharmaceutical drugs, maintaining a stable amorphous form is highly desirable for improved solubility. Glasses prepared by the physical vapor deposition technique got attention because they possess very high stability, taking thousands of years for an ordinary glass to achieve. In this work, we have investigated the effect of reducing film thickness on the α-relaxation dynamics and crystallization tendency of vapor-deposited films of celecoxib (CXB), a pharmaceutical substance. We have scrutinized its crystallization behavior above and below the glass-transition temperature (Tg). Even though vapor deposition of CXB cannot inhibit crystallization completely, we found a significant decrease in the crystallization rate with decreasing film thickness. Finally, we have observed striking differences in relaxation dynamics of vapor-deposited thin films above the Tg compared to spin-coated counterparts of the same thickness.
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Affiliation(s)
- Aparna Beena Unni
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland.,Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Roksana Winkler
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland.,Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Daniel Marques Duarte
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland.,Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Wenkang Tu
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland.,Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Katarzyna Chat
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland.,Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Karolina Adrjanowicz
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland.,Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
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10
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Hengge M, Hänsch P, Ehjeij D, Benneckendorf FS, Freudenberg J, Bunz UHF, Müllen K, List‐Kratochvil EJW, Hermerschmidt F. Crosslinking Super Yellow to produce super OLEDs: Crosslinking with azides enables improved performance. JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1002/pol.20220120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Michael Hengge
- Helmholtz‐Zentrum Berlin für Materialien und Energie GmbH Berlin Germany
| | - Paul Hänsch
- Humboldt‐Universität zu Berlin, Institut für Physik, Institut für Chemie, IRIS Adlershof Berlin Germany
| | - Daniel Ehjeij
- Organisch‐Chemisches Institut, Ruprecht‐Karls‐Universität Heidelberg Heidelberg Germany
- InnovationLab Heidelberg Germany
- Max Planck Institute for Polymer Research Mainz Germany
| | - Frank S. Benneckendorf
- Organisch‐Chemisches Institut, Ruprecht‐Karls‐Universität Heidelberg Heidelberg Germany
- InnovationLab Heidelberg Germany
| | - Jan Freudenberg
- Organisch‐Chemisches Institut, Ruprecht‐Karls‐Universität Heidelberg Heidelberg Germany
- InnovationLab Heidelberg Germany
| | - Uwe H. F. Bunz
- Organisch‐Chemisches Institut, Ruprecht‐Karls‐Universität Heidelberg Heidelberg Germany
- InnovationLab Heidelberg Germany
- Centre for Advanced Materials Ruprecht‐Karls‐Universität Heidelberg Heidelberg Germany
| | - Klaus Müllen
- Max Planck Institute for Polymer Research Mainz Germany
| | - Emil J. W. List‐Kratochvil
- Helmholtz‐Zentrum Berlin für Materialien und Energie GmbH Berlin Germany
- Humboldt‐Universität zu Berlin, Institut für Physik, Institut für Chemie, IRIS Adlershof Berlin Germany
| | - Felix Hermerschmidt
- Humboldt‐Universität zu Berlin, Institut für Physik, Institut für Chemie, IRIS Adlershof Berlin Germany
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11
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Pelczarski D, Korolevych O, Gierczyk B, Zalas M, Makowska-Janusik M, Stampor W. Electronic States of Tris(bipyridine) Ruthenium(II) Complexes in Neat Solid Films Investigated by Electroabsorption Spectroscopy. MATERIALS (BASEL, SWITZERLAND) 2022; 15:2278. [PMID: 35329728 PMCID: PMC8950412 DOI: 10.3390/ma15062278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/04/2022] [Accepted: 03/16/2022] [Indexed: 02/04/2023]
Abstract
We present the electric field-induced absorption (electroabsorption, EA) spectra of the solid neat films of tris(bipyridine) Ru(II) complexes, which were recently functionalized in our group as photosensitizers in dye-sensitized solar cells, and we compare them with the results obtained for an archetypal [Ru(bpy)3]2+ ion (RBY). We argue that it is difficult to establish a unique set of molecular parameter values by discrete parametrization of the EA spectra under the Liptay formalism for non-degenerate excited states. Therefore, the experimental EA spectra are compared with the spectra computed by the TDDFT (time-dependent density-functional theory) method, which for the first time explains the mechanism of electroabsorption in tris(bipyridine) Ru complexes without any additional assumptions about the spectral lineshape of the EA signal. We have shown that the main EA feature, in a form close to the absorption second derivative observed in the spectral range of the first MLCT (metal-to-ligand charge transfer) absorption band in Ru(bpy)3(PF6)2, can be attributed to a delocalized and orbitally degenerate excited state. This result may have key implications for the EA mechanism in RBY-based systems that exhibit similar EA spectra due to the robust nature of MLCT electronic states in such systems.
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Affiliation(s)
- Daniel Pelczarski
- Department of Molecular Photophysics, Institute of Applied Physics and Mathematics, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Oleksandr Korolevych
- Faculty of Science and Technology, Jan Długosz University, Armii Krajowej 13/15, 42-200 Częstochowa, Poland; (O.K.); (M.M.-J.)
| | - Błażej Gierczyk
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland; (B.G.); (M.Z.)
| | - Maciej Zalas
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland; (B.G.); (M.Z.)
| | - Małgorzata Makowska-Janusik
- Faculty of Science and Technology, Jan Długosz University, Armii Krajowej 13/15, 42-200 Częstochowa, Poland; (O.K.); (M.M.-J.)
| | - Waldemar Stampor
- Department of Molecular Photophysics, Institute of Applied Physics and Mathematics, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
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12
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Shoji Y, Kobayashi M, Kosaka A, Haruki R, Kumai R, Adachi SI, Kajitani T, Fukushima T. Design of discotic liquid crystal enabling complete switching between and memory of two alignment states over a large area. Chem Sci 2022; 13:9891-9901. [PMID: 36128239 PMCID: PMC9430577 DOI: 10.1039/d2sc03677k] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 07/19/2022] [Indexed: 11/21/2022] Open
Abstract
The alignment control of discotic columnar liquid crystals (LCs), featuring a low motility of the constituent molecules and thus having a large viscosity, is a challenging task. Here we show that triphenylene hexacarboxylic ester, when functionalized with hybrid side chains consisting of alkyl and perfluoroalkyl groups in an appropriate ratio, gives a hexagonal columnar (Colh) LC capable of selectively forming large-area uniform homeotropic or homogeneous alignments, upon cooling from its isotropic melt or upon application of a shear force at its LC temperature, respectively. In addition to the alignment switching ability, each alignment state remains persistent unless the LC is heated to its melting temperature. In situ X-ray diffraction analysis under the application of a shear force, together with polarized optical microscopy observations, revealed how the columnar assembly is changed during the alignment-switching process. The remarkable behavior of the discotic LC is discussed in terms of its rheological properties. A columnar liquid crystal consisting of a triphenylene hexacarboxylic ester mesogen and semifluoroalkyl side chains shows complete switching between homeotropic and homogeneous alignments, each of which remains persistent up to its melting point.![]()
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Affiliation(s)
- Yoshiaki Shoji
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology 4259 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology 4259 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
| | - Miki Kobayashi
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology 4259 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
| | - Atsuko Kosaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology 4259 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
| | - Rie Haruki
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization 1-1 Oho Tsukuba 305-0801 Japan
| | - Reiji Kumai
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization 1-1 Oho Tsukuba 305-0801 Japan
| | - Shin-Ichi Adachi
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization 1-1 Oho Tsukuba 305-0801 Japan
| | - Takashi Kajitani
- Open Facility Development Office, Open Facility Center, Tokyo Institute of Technology 4259 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
- RIKEN SPring-8 Center 1-1-1 Kouto, Sayo Hyogo 679-5148 Japan
| | - Takanori Fukushima
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology 4259 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology 4259 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
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13
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Vadivel M, Singh S, Singh DP, Raghunathan VA, Kumar S. Ambipolar Charge Transport Properties of Naphthophenanthridine Discotic Liquid Crystals. J Phys Chem B 2021; 125:10364-10372. [PMID: 34482689 DOI: 10.1021/acs.jpcb.1c06009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of novel naphthophenanthridine derivatives are synthesized via N-annulation of hexabutoxytriphenylene-1-amine with various aliphatic aldehydes through the Pictet-Spengler reaction. The synthesized derivatives have been found to self-assemble into a columnar hexagonal mesophase over a wide temperature range, as validated through polarized optical microscopy, differential scanning calorimetry and X-ray diffraction experiments. The photophysical properties of these compounds were studied using UV-visible and emission spectroscopy. The synthesized compounds exhibit ambipolar charge transport, showing temperature-independent electron and hole mobility on the order of 3 × 10-4 cm2/V s, as evaluated by the time-of-flight technique. These novel N-annulated derivatives can be of immense potential toward semiconducting applications of self-assembling supramolecular systems.
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Affiliation(s)
- Marichandran Vadivel
- Soft Condensed Matter Group, Raman Research Institute, C.V.Raman Avenue, Bengaluru 560080, India
| | - Shikha Singh
- Soft Condensed Matter Group, Raman Research Institute, C.V.Raman Avenue, Bengaluru 560080, India
| | - Dharmendra Pratap Singh
- Université du Littoral Côte d'Opale, UR 4476, UDSMM, Unité de Dynamique et Structure des Matériaux Moléculaires, Calais F-62228, France
| | - V A Raghunathan
- Soft Condensed Matter Group, Raman Research Institute, C.V.Raman Avenue, Bengaluru 560080, India
| | - Sandeep Kumar
- Soft Condensed Matter Group, Raman Research Institute, C.V.Raman Avenue, Bengaluru 560080, India.,Department of Chemistry, Nitte Meenakshi Institute of Technology (NMIT), Yelahanka, Bengaluru 560064, India
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14
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Cuerva C, Cano M, Lodeiro C. Advanced Functional Luminescent Metallomesogens: The Key Role of the Metal Center. Chem Rev 2021; 121:12966-13010. [PMID: 34370446 DOI: 10.1021/acs.chemrev.1c00011] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The use of liquid crystals for the fabrication of displays incorporated in technological devices (TVs, calculators, screens of eBook's, tablets, watches) demonstrates the relevance that these materials have had in our way of living. However, society evolves, and improved devices are looked for as we create a more efficient and safe technology. In this context, metallomesogens can behave as multifunctional materials because they can combine the fluidic state of the mesophases with properties such as photo and electroluminescence, which offers new exciting possibilities in the field of optoelectronics, energy, environment, and even biomedicine. Herein, it has been established the role of the molecular geometry induced by the metal center in metallomesogens to achieve the self-assembly required in the liquid-crystalline mesophase. Likewise, the effect of the coordination environment in metallomesogens has been further analyzed because of its importance to induce mesomorphism. The structural analysis has been combined with an in-depth discussion of the properties of these materials, including their current and potential future applications. This review will provide a solid background to stimulate the development of novel and attractive metallomesogens that allow designing improved optoelectronic and microelectronic components. Additionally, nanoscience and nanotechnology could be used as a tool to approach the design of nanosystems based on luminescent metallomesogens for use in bioimaging or drug delivery.
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Affiliation(s)
- Cristián Cuerva
- BIOSCOPE Research Group, LAQV@REQUIMTE Chemistry Department, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal
| | - Mercedes Cano
- Department of Inorganic Chemistry, Complutense University of Madrid, Ciudad Universitaria, 28040 Madrid, Spain
| | - Carlos Lodeiro
- BIOSCOPE Research Group, LAQV@REQUIMTE Chemistry Department, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal.,PROTEOMASS Scientific Society, Rua dos Inventores, Madam Parque, Caparica Campus, 2829-516 Caparica, Portugal
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15
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Zhu M, Chen M, Guo H, Yang F. Fluorescein-bridged Perylene Bisimide Dimer for Use as Liquid Crystal: Studies on Mesomorphic and Fluorescence Properties. J Fluoresc 2021; 31:1555-1565. [PMID: 34338968 DOI: 10.1007/s10895-021-02793-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 07/26/2021] [Indexed: 10/20/2022]
Abstract
A novel fluorescein-bridged perylene bisimide (PBI) dimer for liquid crystal (LC) with geometrically symmetric structure was developed. The mesomorphic results indicated that the energetically stable and unstable conformers of fluorescein fragments could lead to the transformation of mesophases from a hexagonal columnar mesophase to an uncertain phase at 136.9 °C in heating, whilst a stable hexagonal columnar mesophase maintained between 175.6 °C and 58.6 °C in cooling. The selectively excited fluorescence characters in THF solution demonstrated that the fluorescence resonance energy transfer (FRET) effect between fluorescein fragments and PBI unites could provide a means to effectively impose strong fluorescence of the dimeric PBIs modified with suitable chromophore at the N-imide position, which alternatively serves as a platform for the further study of multi-functional PBI-based LCs.
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Affiliation(s)
- Mingguang Zhu
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, P. R. China. .,College of Chemistry and Chemical Engineering, Neijiang Normal University, Neijiang, 641100, P. R. China.
| | - Meihui Chen
- College of Chemistry and Chemical Engineering, Neijiang Normal University, Neijiang, 641100, P. R. China
| | - Hongyu Guo
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, P. R. China.,Fujian Key Laboratory of Polymer Materials, Fuzhou, 350007, P. R. China
| | - Fafu Yang
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, P. R. China. .,Fujian Provincial Key Laboratory of Advanced, Materials Oriented Chemical Engineering, Fuzhou, 350007, P. R. China.
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16
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Bishop C, Chen Z, Toney MF, Bock H, Yu L, Ediger MD. Using Deposition Rate and Substrate Temperature to Manipulate Liquid Crystal-Like Order in a Vapor-Deposited Hexagonal Columnar Glass. J Phys Chem B 2021; 125:2761-2770. [PMID: 33683124 DOI: 10.1021/acs.jpcb.0c11564] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We investigate vapor-deposited glasses of a phenanthroperylene ester, known to form an equilibrium hexagonal columnar phase, and show that liquid crystal-like order can be manipulated by the choice of deposition rate and substrate temperature during deposition. We find that rate-temperature superposition (RTS)-the equivalence of lowering the deposition rate and increasing the substrate temperature-can be used to predict and control the molecular orientation in vapor-deposited glasses over a wide range of substrate temperatures (0.75-1.0 Tg). This work extends RTS to a new structural motif, hexagonal columnar liquid crystal order, which is being explored for organic electronic applications. By several metrics, including the apparent average face-to-face nearest-neighbor distance, physical vapor deposition (PVD) glasses of the phenanthroperylene ester are as ordered as the glass prepared by cooling the equilibrium liquid crystal. By other measures, the PVD glasses are less ordered than the cooled liquid crystal. We explain the difference in the maximum attainable order with the existence of a gradient in molecular mobility at the free surface of a liquid crystal and its impact upon different mechanisms of structural rearrangement. This free surface equilibration mechanism explains the success of the RTS principle and provides guidance regarding the types of order most readily enhanced by vapor deposition. This work extends the applicability of RTS to include molecular systems with a diverse range of higher-order liquid-crystalline morphologies that could be useful for new organic electronic applications.
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Affiliation(s)
- Camille Bishop
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, Wisconsin 53706, United States
| | - Zhenxuan Chen
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Ave, Madison, Wisconsin 53705, United States
| | - Michael F Toney
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Harald Bock
- Centre de Recherche Paul Pascal, CNRS & Université de Bordeaux, 115, av. Schweitzer, 33600 Pessac, France
| | - Lian Yu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, Wisconsin 53706, United States.,School of Pharmacy, University of Wisconsin-Madison, 777 Highland Ave, Madison, Wisconsin 53705, United States
| | - M D Ediger
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, Wisconsin 53706, United States
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17
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Birudula S, Prabhu DD, Ghosh T, B A, Das S, Vijayaraghavan RK. Directed Self-Organization Ensured Enhancement of Charge Carrier Mobilities in a Star-Shaped Organic Semiconductor. Chemistry 2020; 26:11135-11140. [PMID: 32428357 DOI: 10.1002/chem.202001615] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/02/2020] [Indexed: 12/25/2022]
Abstract
Controlled self-organization of organic semiconductor molecules into specifically desired architectures on substrates of interest is one of the most imperative challenges faced in the fabrication of high-performance organic electronic devices. Herein, we report the self-organization of a star-shaped molecule FDT-8 into a highly favored structure, namely, a vertical stack. Thermal annealing of films of FDT-8 deposited on PEDOT: PSS coated ITO substrates was observed to assist the organization of the molecules into columnar stacks. A significant enhancement in the hole (≈50-fold) and the electron (≈13-fold) carrier mobility was observed in single-carrier devices upon thermal annealing that could be attributed to the aforementioned self-organization. The ability of these molecules to spontaneously self-organize was utilized to fabricate bilayer light-emitting devices.
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Affiliation(s)
- Srikanth Birudula
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
| | - Deepak D Prabhu
- Photosciences and Photonics, Chemical Science and Technology Division, NIIST (CSIR), Trivandrum, 695019, India
| | - Tapan Ghosh
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
| | - Adara B
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
| | - Suresh Das
- Photosciences and Photonics, Chemical Science and Technology Division, NIIST (CSIR), Trivandrum, 695019, India.,School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, 695551, India
| | - Ratheesh K Vijayaraghavan
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
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18
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Lehmann M, Dechant M, Weh D, Freytag E. Metal Phthalocyanine−Fullerene Dyads: Promising Lamellar Columnar Donor−Acceptor Liquid Crystal Phases. Chempluschem 2020; 85:1934-1938. [DOI: 10.1002/cplu.202000540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/01/2020] [Indexed: 11/08/2022]
Affiliation(s)
- Matthias Lehmann
- Institute of Organic ChemistryUniversity of Würzburg Am Hubland 97074 Würzburg Germany
- Center for Nanosystems Chemistryand Bavarian Polymer Institute Theodor-Boveri-Weg 4 97074 Würzburg Germany
| | - Moritz Dechant
- Institute of Organic ChemistryUniversity of Würzburg Am Hubland 97074 Würzburg Germany
| | - Dominik Weh
- Institute of Organic ChemistryUniversity of Würzburg Am Hubland 97074 Würzburg Germany
| | - Emely Freytag
- Institute of Organic ChemistryUniversity of Würzburg Am Hubland 97074 Würzburg Germany
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19
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Fujimoto K, Takahashi M, Izawa S, Hiramoto M. Development of Perylene-Based Non-Fullerene Acceptors through Bay-Functionalization Strategy. MATERIALS 2020; 13:ma13092148. [PMID: 32384804 PMCID: PMC7254288 DOI: 10.3390/ma13092148] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 12/15/2022]
Abstract
Perylene has had a tremendous impact in the history of material research for the molecular semiconductors. Among numerous derivatives of this polyaromatic hydrocarbon, perylene diimide (PDI) represents a promising class of organic materials envisioned as non-fullerene acceptors (NFAs) for the practical organic photovoltaic (OPV) applications due to their enhanced photo- and thermal stability and remarkably high electron affinity, some of which realize band-like transport properties. The present review guides some of the representative achievements in the development of rationally designed PDI systems, highlighting synthetic methodologies based on bay-functionalization strategies for creating well-designed molecular nanostructures and structure-performance relationship of perylene-based small molecular acceptors (SMAs) for the photovoltaic outcomes.
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Affiliation(s)
- Keisuke Fujimoto
- Department of Applied Chemistry, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka 432-8561, Japan;
| | - Masaki Takahashi
- Department of Applied Chemistry, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka 432-8561, Japan;
- Correspondence: ; Tel.: +81-53-478-1621
| | - Seiichiro Izawa
- Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; (S.I.); (M.H.)
| | - Masahiro Hiramoto
- Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; (S.I.); (M.H.)
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20
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Vapor deposition of a nonmesogen prepares highly structured organic glasses. Proc Natl Acad Sci U S A 2019; 116:21421-21426. [PMID: 31527259 DOI: 10.1073/pnas.1908445116] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We show that glasses with aligned smectic liquid crystal-like order can be produced by physical vapor deposition of a molecule without any equilibrium liquid crystal phases. Smectic-like order in vapor-deposited films was characterized by wide-angle X-ray scattering. A surface equilibration mechanism predicts the highly smectic-like vapor-deposited structure to be a result of significant vertical anchoring at the surface of the equilibrium liquid, and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy orientation analysis confirms this prediction. Understanding of the mechanism enables informed engineering of different levels of smectic order in vapor-deposited glasses to suit various applications. The preparation of a glass with orientational and translational order from a nonliquid crystal opens up an exciting paradigm for accessing extreme anisotropy in glassy solids.
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21
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Kong S, Wang X, Bai L, Song Y, Meng F. Multi-arm ionic liquid crystals formed by pyridine-mesophase and copper phthalocyanine. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111012] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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22
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Gupta RK, Sudhakar AA. Perylene-Based Liquid Crystals as Materials for Organic Electronics Applications. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:2455-2479. [PMID: 29929366 DOI: 10.1021/acs.langmuir.8b01081] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Columnar phases formed by the stacking of disclike molecules with an intimate π-π overlap forms a 1D pathway for the anisotropic charge migration along the columns. Columnar phases have great potential in organic electronic devices to be utilized as active semiconducting layers in comparison to organic single crystals or amorphous polymers in terms of processability, ease of handling, and high charge carrier mobility. Intelligent molecular engineering of perylene and its derivatives provided access to tune the physical properties and self-assembly behavior. The columnar phase formed by perylene derivatives has great potential in the fabrication of organic electronic devices. There are several positions on the perylene molecule, which can be functionalized to tune its self-assembly, as well as optoelectronic properties. Thus, many liquid-crystalline molecules stabilizing the columnar phase, which are based on perylene tetraesters, perylene diester imides, and perylene bisimides, have been synthesized over the years. Their longitudinal and laterally extended derivatives, bay-substituted derivatives exhibiting a columnar phase, are reported. In addition, several liquid-crystalline oligomers and polymers based on perylene derivatives were also reported. All such modifications provide an option to tune the energy levels of frontier molecular orbitals with respect to the work function of the electrodes in devices and also the processability of such materials. In this feature article, we attempt to provide an overview of the molecular design developed to tune the applicable properties and self-assembly of perylene derivatives as well as recent developments related to their application in the fabrication of organic solar cells, organic light-emitting diodes, and organic field-effect transistors.
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Affiliation(s)
- Ravindra Kumar Gupta
- Department of Chemistry , Indian Institute of Technology Guwahati , Guwahati 781039 , Assam , India
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23
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Abstract
The term "organic solids" encompasses both crystals and glasses. Organic crystals are commonly grown for purification and structure determination and are being extensively explored for applications in organic electronics including field effect transistors. The ability to control the packing of one molecule relative to its neighbors is of critical importance for most uses of organic crystals. Often, anisotropic packing is also highly desirable as it enhances charge transport and optimizes light absorption/emission. When compared to crystals, the local packing in organic glasses is highly disordered and often isotropic. Glasses, however, offer two key advantages with respect to crystals. First, glasses typically lack grain boundaries and thus exhibit better macroscopic homogeneity. Second, glass composition can often be varied over a wide range while maintaining homogeneity. Besides electronic materials, many modern plastics used in a wide range of technologies are organic glasses, and the glassy state is being increasingly utilized to deliver pharmaceuticals because of higher bioavailability. In this article, we introduce vapor-deposited organic glasses as hybrid materials that combine some of the useful features of crystals and traditional liquid-cooled glasses. Physical vapor deposition produces glasses by directly condensing molecules from the gas phase onto a temperature-controlled substrate and allows film thickness to be controlled with nanometer precision. Just as liquid-cooled glasses, vapor-deposited glasses have smooth surfaces and lack grain boundaries. These attributes are critical for applications such as organic light emitting diodes (OLEDs), in which vapor-deposited glasses of organic semiconductors form the active layers. In common with crystals, vapor-deposited glasses can exhibit anisotropic packing, and the extent of anisotropy can be comparable to that of the typical organic crystal. For vapor-deposited glasses, in contrast to crystals, anisotropic packing can generally be controlled as a continuous variable. Deposition conditions can be chosen to produce glasses with significant molecular orientation (molecules "standing up" or "lying down" relative to the substrate), and π-stacking can be directed along different directions relative to the substrate. Over the last five years, we have gained a fundamental understanding of the mechanism that controls the anisotropy of vapor-deposited glasses and learned how to control many aspects of anisotropic packing. Two key elements that enable such control are the high mobility present at the surface of an organic glass and the tendency of the surface to promote anisotropic packing of molecules. In contrast to traditional epitaxial growth, for vapor-deposited glasses, the free surface (not the substrate) acts as a template that controls the structure of a growing film. The structure of any given layer is decoupled from those beneath it, thereby providing considerable freedom in producing layered glassy structures.
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Affiliation(s)
- M. D. Ediger
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Juan de Pablo
- Institute of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Lian Yu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705, United States
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24
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Kong S, Song Y, Bai L, Tang X, Meng F. Supramolecular complexes based on liquid-crystalline polysiloxanes and copper phthalocyanine. POLYM INT 2018. [DOI: 10.1002/pi.5720] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Shengwen Kong
- College of Science; Northeastern University; Shenyang China
| | - Ying Song
- College of Science; Northeastern University; Shenyang China
| | - Lu Bai
- College of Science; Northeastern University; Shenyang China
| | - Xinqiao Tang
- College of Science; Northeastern University; Shenyang China
| | - Fanbao Meng
- College of Science; Northeastern University; Shenyang China
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25
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Echeverri M, Martín I, Concellón A, Ruiz C, Anselmo MS, Gutiérrez-Puebla E, Serrano JL, Gómez-Lor B. Fluorescent and Electroactive Monoalkyl BTD-Based Liquid Crystals with Tunable Self-Assembling and Electronic Properties. ACS OMEGA 2018; 3:11857-11864. [PMID: 31459271 PMCID: PMC6644942 DOI: 10.1021/acsomega.8b01696] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 09/11/2018] [Indexed: 06/10/2023]
Abstract
We report here on a series of redox active benzothiadiazole-based luminophores functionalized on one edge with a phenyl-nonyl substituent, which confers these molecules a rodlike shape and a tendency to self-assemble into layered superstructures. On the other edge, the molecules are endowed with different p-substituted phenyl rings, which allows the modulation of their redox and optical properties on the basis of the electronic nature of the terminal substituents. We have found that just one lateral alkyl chain is sufficient to induce mesomorphism in these molecules, which present nematic or smectic mesophases upon thermal treatment. Single-crystal analysis allows us to get an insight into the nature of the forces responsible for different supramolecular assemblies in these derivatives, and point to a strong contribution of the terminal groups in the different arrangements observed. The interesting redox and optical properties together with their self-assembling tendencies render these new materials interesting candidates for optoelectronics.
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Affiliation(s)
- Marcelo Echeverri
- Material
Science Factory, Instituto de Ciencia de
Materiales de Madrid, Cantoblanco, 20849 Madrid, Spain
| | - Irene Martín
- Material
Science Factory, Instituto de Ciencia de
Materiales de Madrid, Cantoblanco, 20849 Madrid, Spain
| | - Alberto Concellón
- Dpto.
Química Orgánica, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Constanza Ruiz
- Material
Science Factory, Instituto de Ciencia de
Materiales de Madrid, Cantoblanco, 20849 Madrid, Spain
| | - María San Anselmo
- Dpto.
Química Orgánica, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Enrique Gutiérrez-Puebla
- Material
Science Factory, Instituto de Ciencia de
Materiales de Madrid, Cantoblanco, 20849 Madrid, Spain
| | - José L. Serrano
- Dpto.
Química Orgánica, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Berta Gómez-Lor
- Material
Science Factory, Instituto de Ciencia de
Materiales de Madrid, Cantoblanco, 20849 Madrid, Spain
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26
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Zhu M, Chen Y, Zhang X, Chen M, Guo H, Yang F. Perylene bisimide with diphenylacrylonitrile on side-chain: strongly fluorescent liquid crystal with large pseudo Stokes shift based on AIE and FRET effect. SOFT MATTER 2018; 14:6737-6744. [PMID: 30062329 DOI: 10.1039/c8sm01183d] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A novel perylene bisimide (PBI) derivative with an AIE-active diphenylacrylonitrile unit positioned at the terminal N-imide position through a flexible spacer has been synthesized and characterized. The DSC, POM and XRD studies confirmed that it could self-assemble into a stable hexagonal columnar liquid-crystalline phase between 56 °C and 160 °C. This PBI derivative also exhibited strong fluorescence in solution, thin film and mesophase based on the cooperative mechanism of AIE and FRET between the diphenylacrylonitrile group and perylene moiety. The pseudo Stokes shift was as large as 283 nm, and the fluorescence quantum yields were as high as 0.62-0.79 in solution and 0.68-0.86 in solid state. This study provides a good strategy for converting the columnar liquid crystal with ACQ effect to one with the AIE effect, successfully filling the gap between the excellent columnar mesomorphic properties and strong fluorescence in solid state.
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Affiliation(s)
- Mingguang Zhu
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, P. R. China.
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27
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Zhu M, Chen Y, Guo H, Yang F, Song X. Perylene liquid crystals with multiple alkyl chains: investigation of the influence of peripheral alkyl chain number on mesomorphic and photophysical properties. NEW J CHEM 2018. [DOI: 10.1039/c8nj00480c] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Novel perylene liquid crystals with 2, 4 and 6 peripheral alkyl chains or 6, 8 and 10 peripheral alkyl chains at both the imide and bay-positions were investigated.
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Affiliation(s)
- Mingguang Zhu
- College of Chemistry and Materials Science
- Fujian Normal University
- Fuzhou 350007
- P. R. China
| | - Yongzhu Chen
- College of Chemistry and Materials Science
- Fujian Normal University
- Fuzhou 350007
- P. R. China
| | - Hongyu Guo
- College of Chemistry and Materials Science
- Fujian Normal University
- Fuzhou 350007
- P. R. China
| | - Fafu Yang
- College of Chemistry and Materials Science
- Fujian Normal University
- Fuzhou 350007
- P. R. China
- Fujian Key Laboratory of Polymer Materials
| | - Xuchun Song
- College of Chemistry and Materials Science
- Fujian Normal University
- Fuzhou 350007
- P. R. China
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28
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Wang YF, Iino H, Hanna JI. Fabrication of planarly-oriented polycrystalline thin films of smectic liquid crystalline organic semiconductors. SOFT MATTER 2017; 13:6499-6505. [PMID: 28890976 DOI: 10.1039/c7sm01303e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Fabrication of planarly-oriented polycrystalline thin films of organic semiconductors was investigated, in which molecules sit parallel, i.e., "face-on" on the substrate so as to allow vertical charge transport favorably through a thin film. With the aid of self-organization of liquid crystalline molecules and an over-coated orientation layer, tens of nm thin films vertically oriented can be re-oriented from "hemeotropic, or vertical" to "homogenous or planar" to achieve polycrystalline thin films planarly oriented after removing the over-coated orientation layer. We investigated the key factors to affect re-orientation of the films and uniformity and surface morphology of the resulting films, including conditions required for the re-orientation and properties of the orientation layer materials and liquid crystals.
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Affiliation(s)
- Yi-Fei Wang
- Imaging Science and Engineering Research Center, Tokyo Institute of Technology, 4259-J1-2 Nagatsuta Midori-ku, Yokohama 226-8503, Japan.
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29
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Vollbrecht J, Blazy S, Dierks P, Peurifoy S, Bock H, Kitzerow H. Electroluminescent and Optoelectronic Properties of OLEDs with Bay-Extended, Distorted Perylene Esters as Emitter Materials. Chemphyschem 2017; 18:2024-2032. [PMID: 28488359 DOI: 10.1002/cphc.201700502] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Indexed: 11/10/2022]
Abstract
Three esters with a perylene, a unilaterally, and a bilaterally extended perylene core, respectively, were used as emitter materials for organic light-emitting diodes. The electroluminescent properties of these devices were studied. Different spectral shifts were found, which can be attributed to the formation of excited dimers (excimers) in the nanofilms of the emitter materials. Thermal treatment of the unilaterally extended derivative resulted in a red-shift of the electroluminescence owing to the formation of a denser nanofilm. The luminance and efficiency of optoelectronic devices employing the extended perylene esters exceed those of devices using an emitter layer comprised of the perylene ester. Different deposition methods, limitations in the deposition process, and the role of hole-transporting materials are compared.
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Affiliation(s)
- Joachim Vollbrecht
- Department of Chemistry, Physical Chemistry, Universität Paderborn, Warburger Strasse 100, 33098, Paderborn, Germany.,Center for Optoelectronics and Photonics Paderborn, Universität Paderborn, Warburger Strasse 100, 33098, Paderborn, Germany
| | - Simon Blazy
- Department of Chemistry, Physical Chemistry, Universität Paderborn, Warburger Strasse 100, 33098, Paderborn, Germany
| | - Philipp Dierks
- Department of Chemistry, Physical Chemistry, Universität Paderborn, Warburger Strasse 100, 33098, Paderborn, Germany
| | - Samuel Peurifoy
- Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | - Harald Bock
- Centre de Recherche Paul Pascal (CRPP), CNRS, Universite Bordeaux, 33600, Pessac, France
| | - Heinz Kitzerow
- Department of Chemistry, Physical Chemistry, Universität Paderborn, Warburger Strasse 100, 33098, Paderborn, Germany.,Center for Optoelectronics and Photonics Paderborn, Universität Paderborn, Warburger Strasse 100, 33098, Paderborn, Germany
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30
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Cuerva C, Campo JA, Cano M, Schmidt R. Nanostructured discotic Pd(ii) metallomesogens as one-dimensional proton conductors. Dalton Trans 2017; 46:96-105. [DOI: 10.1039/c6dt03521c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Bis(isoquinolinylpyrazolate) Pd(ii) metallomesogens may be a promising step forward in the design of highly-stable proton conducting water-free electrolyte materials.
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Affiliation(s)
- Cristián Cuerva
- Departamento de Química Inorgánica I
- Facultad de Ciencias Químicas
- Universidad Complutense de Madrid
- Ciudad Universitaria
- E-28040 Madrid
| | - José A. Campo
- Departamento de Química Inorgánica I
- Facultad de Ciencias Químicas
- Universidad Complutense de Madrid
- Ciudad Universitaria
- E-28040 Madrid
| | - Mercedes Cano
- Departamento de Química Inorgánica I
- Facultad de Ciencias Químicas
- Universidad Complutense de Madrid
- Ciudad Universitaria
- E-28040 Madrid
| | - Rainer Schmidt
- GFMC. Departamento de Física Aplicada III
- Universidad Complutense de Madrid
- Ciudad Universitaria
- E-28040 Madrid
- Spain
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31
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Ruiz C, Pandey UK, Termine R, García-Frutos EM, López-Espejo G, Ortiz RP, Huang W, Marks TJ, Facchetti A, Ruiz Delgado MC, Golemme A, Gómez-Lor B. Mobility versus Alignment of a Semiconducting π-Extended Discotic Liquid-Crystalline Triindole. ACS APPLIED MATERIALS & INTERFACES 2016; 8:26964-26971. [PMID: 27643623 DOI: 10.1021/acsami.6b06241] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The p-type semiconducting properties of a triphenylene-fused triindole mesogen, have been studied by applying two complementary methods which have different alignment requirements. The attachment of only three flexible alkyl chains to the nitrogen atoms of this π-extended core is sufficient to induce columnar mesomorphism. High hole mobility values (0.65 cm2 V-1 s-1) have been estimated by space-charge limited current (SCLC) measurements in a diode-like structure which are easily prepared from the melt, rendering this material a good candidate for OPVs and OLEDs devices. The mobility predicted theoretically via a hole-hopping mechanism is in very good agreement with the experimental values determined at the SCLC regime. On the other hand the hole mobility determined on solution processed thin film transistors (OFETs) is significantly lower, which can be rationalized by the high tendency of these large molecules to align on surfaces with their extended π-conjugated core parallel to the substrate as demonstrated by SERS. Despite the differences obtained with the two methods, the acceptable performance found on OFETs fabricated by simple drop-casting processing of such an enlarged aromatic core is remarkable and suggests facile hopping between neighboring molecular columns owing to the large conducting/isolating ratio found in this discotic compound.
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Affiliation(s)
- Constanza Ruiz
- Instituto de Ciencia de Materiales de Madrid, CSIC , Cantoblanco, 28049, Madrid, Spain
- Department of Chemistry and the Materials Research Center, the Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Upendra K Pandey
- LASCAMM CR-INSTM, CNR-NANOTEC Lab LiCryL, Dipartimento di Fisica, Università della Calabria , 87036 Rende, Italy
- Interdisciplinary Centre for Energy Research, Indian Institute of Science , Bangalore, 560012, India
| | - Roberto Termine
- LASCAMM CR-INSTM, CNR-NANOTEC Lab LiCryL, Dipartimento di Fisica, Università della Calabria , 87036 Rende, Italy
| | - Eva M García-Frutos
- Instituto de Ciencia de Materiales de Madrid, CSIC , Cantoblanco, 28049, Madrid, Spain
| | - Guzmán López-Espejo
- Department of Physical Chemistry, University of Málaga , 29071, Málaga, Spain
| | - Rocío Ponce Ortiz
- Department of Physical Chemistry, University of Málaga , 29071, Málaga, Spain
| | - Wei Huang
- Department of Chemistry and the Materials Research Center, the Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Tobin J Marks
- Department of Chemistry and the Materials Research Center, the Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Antonio Facchetti
- Department of Chemistry and the Materials Research Center, the Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | | | - Attilio Golemme
- LASCAMM CR-INSTM, CNR-NANOTEC Lab LiCryL, Dipartimento di Fisica, Università della Calabria , 87036 Rende, Italy
| | - Berta Gómez-Lor
- Instituto de Ciencia de Materiales de Madrid, CSIC , Cantoblanco, 28049, Madrid, Spain
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32
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Gómez J, Jiang J, Gujral A, Huang C, Yu L, Ediger MD. Vapor deposition of a smectic liquid crystal: highly anisotropic, homogeneous glasses with tunable molecular orientation. SOFT MATTER 2016; 12:2942-2947. [PMID: 26875700 DOI: 10.1039/c5sm02944a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Physical vapor deposition (PVD) has been used to prepare glasses of itraconazole, a smectic A liquid crystal. Glasses were deposited onto subtrates at a range of temperatures (Tsubstrate) near the glass transition temperature (Tg), with Tsubstrate/Tg ranging from 0.70 to 1.02. Infrared spectroscopy and spectroscopic ellipsometry were used to characterize the molecular orientation using the orientational order parameter, Sz, and the birefringence. We find that the molecules in glasses deposited at Tsubstrate = Tg are nearly perpendicular to the substrate (Sz = +0.66) while at lower Tsubstrate molecules are nearly parallel to the substrate (Sz = -0.45). The molecular orientation depends on the temperature of the substrate during preparation, allowing layered samples with differing orientations to be readily prepared. In addition, these vapor-deposited glasses are macroscopically homogeneous and molecularly flat. We interpret the combination of properties obtained for vapor-deposited glasses of itraconazole to result from a process where molecular orientation is determined by the structure and dynamics at the free surface of the glass during deposition. Vapor deposition of liquid crystals is likely a general approach for the preparation of highly anisotropic glasses with tunable molecular orientation for use in organic electronics and optoelectronics.
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Affiliation(s)
- Jaritza Gómez
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA.
| | - Jing Jiang
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Ankit Gujral
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA.
| | - Chengbin Huang
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705-2222, USA
| | - Lian Yu
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705-2222, USA
| | - M D Ediger
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA.
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33
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Apostol P, Eccher J, Dotto MER, Costa CB, Cazati T, Hillard EA, Bock H, Bechtold IH. High rectification in organic diodes based on liquid crystalline phthalocyanines. Phys Chem Chem Phys 2015; 17:32390-7. [PMID: 26585027 DOI: 10.1039/c5cp05582b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The optical and electrical properties of mesogenic metal-free and metalated phthalocyanines (PCs) with a moderately sized and regioregular alkyl periphery were investigated. In solution, the individualized molecules show fluorescence lifetimes of 4-6 ns in THF. When deposited as solid thin films the materials exhibit significantly shorter fluorescence lifetimes with bi-exponential decay (1.4-1.8 ns; 0.2-0.4 ns) that testify to the formation of aggregates viaπ-π intermolecular interactions. In diode structures, their pronounced columnar order outbalances the unfavorable planar alignment and leads to excellent rectification behavior. Field-dependent charge carrier mobilities are obtained from the J-V curves in the trap-limited space-charge-limited current regime and demonstrate that the metalated PCs display an improved electrical response with respect to the metal-free homologue. The excited-state lifetime characterization suggest that the π-π intermolecular interactions are stronger for the metal-free PC, confirming that the metallic centre plays an important role in the charge transport inside these materials.
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Affiliation(s)
- Petru Apostol
- Centre de Recherche Paul Pascal, Université de Bordeaux & CNRS, 115 Avenue Schweitzer, 33600 Pessac, France
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