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Smit R, Ristanović Z, Deperasińska I, Kozankiewicz B, Orrit M. Probing the in-plane dipole moment vector between ground and excited state of single molecules by the Stark effect. Chemphyschem 2024; 25:e202300881. [PMID: 38206192 DOI: 10.1002/cphc.202300881] [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: 11/17/2023] [Revised: 12/22/2023] [Accepted: 01/02/2024] [Indexed: 01/12/2024]
Abstract
Single molecules, embedded inside a well-defined insertion site of a single-crystalline host matrix, are sensitive probes of electric field via the induced Stark shift on their lifetime-limited electronic transition. Though the response of molecules to electric field has been shown to be relatively homogeneous, crystal symmetry allows for several, spectroscopically-indistinguishable, orientations of the net permanent dipole moment between the ground and excited state - the dipole vector - and this is problematic for measuring field orientation and magnitude. In this work, we measure for each terrylene molecule, embedded inside a new host matrix, the dipole vector independently by an electric field that we can rotate in the plane of the crystal. This single crystal host matrix, called [1]BenzoThieno[3,2-b]BenzoThiophene, induces a moderate symmetry breaking of the embedded centrosymmetric terrylene molecule, and gives rise to a net dipole moment of 0.28±0.09 Debye. Based on quantum chemistry calculations we propose an insertion site that best matches the experimental findings.
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Affiliation(s)
- Robert Smit
- Huygens-Kamerlingh Onnes Laboratory, LION, Postbus 9504, 2300, RA Leiden, The Netherlands
| | - Zoran Ristanović
- Huygens-Kamerlingh Onnes Laboratory, LION, Postbus 9504, 2300, RA Leiden, The Netherlands
| | - Irena Deperasińska
- Institute of Physics, Polish Academy of Sciences Al., Lotnikow 32/46, 02-668, Warsaw, Poland
| | - Bolesław Kozankiewicz
- Institute of Physics, Polish Academy of Sciences Al., Lotnikow 32/46, 02-668, Warsaw, Poland
| | - Michel Orrit
- Huygens-Kamerlingh Onnes Laboratory, LION, Postbus 9504, 2300, RA Leiden, The Netherlands
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2
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Chen D, Tenopala‐Carmona F, Knöller JA, Mischok A, Hall D, Madayanad Suresh S, Matulaitis T, Olivier Y, Nacke P, Gießelmann F, Laschat S, Gather MC, Zysman‐Colman E. Mesogenic Groups Control the Emitter Orientation in Multi-Resonance TADF Emitter Films. Angew Chem Int Ed Engl 2023; 62:e202218911. [PMID: 36760211 PMCID: PMC10947294 DOI: 10.1002/anie.202218911] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023]
Abstract
The use of thermally activated delayed fluorescence (TADF) emitters and emitters that show preferential horizontal orientation of their transition dipole moment (TDM) are two emerging strategies to enhance the efficiency of OLEDs. We present the first example of a liquid crystalline multi-resonance TADF (MR-TADF) emitter, DiKTa-LC. The compound possesses a nematic liquid crystalline phase between 80 °C and 110 °C. Importantly, the TDM of the spin-coated film shows preferential horizontal orientation, with an anisotropy factor, a, of 0.28, which is preserved in doped poly(vinylcarbazole) films. Green-emitting (λEL =492 nm) solution-processed OLEDs based on DiKTa-LC showed an EQEmax of 13.6 %. We thus demonstrate for the first time how self-assembly of a liquid crystalline TADF emitter can lead to the so-far elusive control of the orientation of the transition dipole in solution-processed films, which will be of relevance for high-performance solution-processed OLEDs.
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Affiliation(s)
- Dongyang Chen
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
| | - Francisco Tenopala‐Carmona
- Humboldt Centre for Nano- and BiophotonicsDepartment of ChemistryUniversity of CologneGreinstr. 4-650939KölnGermany
| | - Julius A. Knöller
- Institut für Organische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Andreas Mischok
- Humboldt Centre for Nano- and BiophotonicsDepartment of ChemistryUniversity of CologneGreinstr. 4-650939KölnGermany
| | - David Hall
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
- Laboratory for Chemistry of Novel MaterialsUniversity of MonsMonsBelgium
| | - Subeesh Madayanad Suresh
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
| | - Tomas Matulaitis
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
| | - Yoann Olivier
- Laboratory for Computational Modeling of Functional MaterialsNamur Institute of Structured MatterUniversité de NamurRue de Bruxelles 615000NamurBelgium
| | - Pierre Nacke
- Institut für Physikalische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Frank Gießelmann
- Institut für Physikalische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Sabine Laschat
- Institut für Organische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Malte C. Gather
- Humboldt Centre for Nano- and BiophotonicsDepartment of ChemistryUniversity of CologneGreinstr. 4-650939KölnGermany
| | - Eli Zysman‐Colman
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
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3
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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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4
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Yang Y, Wang Y, Qiao J, Zhao W, Yu Y, Feng S, An X, Zhang J, Ji W, Wang X, Lu J, Ni Z. Aggregation-Dependent Dielectric Permittivity in 2D Molecular Crystals. SMALL METHODS 2022; 6:e2101198. [PMID: 35174978 DOI: 10.1002/smtd.202101198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 01/13/2022] [Indexed: 06/14/2023]
Abstract
The functionality of 2D molecular crystal-based devices crucially depends on their intrinsic properties, such as molecular energy levels, light absorption efficiency, and dielectric permittivity, which are highly sensitive to molecular aggregation. Here, it is demonstrated that the dielectric permittivity of the 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8 -BTBT) molecular crystals on monolayer WS2 substrates can be tuned from 4.62 in the wetting layer to 2.25 in the second layer. Its origin lies in the different molecular orientations in the wetting layer (lying-down) and in the subsequently stacked layers (standing-up), which lead to a positive Coulomb coupling (JCoup ) value (H-aggregation) and a negative JCoup value (J-aggregation), respectively. Polarized optical contrast spectroscopy reveals that the permittivity of C8 -BTBT is anisotropic, and its direction is related to the underlying substrate. The study offers guidelines for future manipulation of the permittivity of 2D molecular crystals, which may promote their applications toward various electronic and optoelectronic devices.
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Affiliation(s)
- Yutian Yang
- School of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing, 211189, P. R. China
| | - Yingying Wang
- Department of Optoelectronic Science, Harbin Institute of Technology at Weihai, Weihai, 264209, P. R. China
| | - Jingsi Qiao
- Beijing Key Laboratory of Optoelectronic Functional Materials & MicroNano Devices, Renmin University of China, Beijing, 100872, P. R. China
| | - Weiwei Zhao
- School of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing, 211189, P. R. China
| | - Yuanfang Yu
- School of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing, 211189, P. R. China
| | - Shaopeng Feng
- School of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing, 211189, P. R. China
| | - Xuhong An
- School of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing, 211189, P. R. China
| | - Jialin Zhang
- School of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing, 211189, P. R. China
| | - Wei Ji
- Beijing Key Laboratory of Optoelectronic Functional Materials & MicroNano Devices, Renmin University of China, Beijing, 100872, P. R. China
| | - Xinran Wang
- National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, P. R. China
| | - Junpeng Lu
- School of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing, 211189, P. R. China
| | - Zhenhua Ni
- School of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing, 211189, P. R. China
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5
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Light Propagation in Confined Nematic Liquid Crystals and Device Applications. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11188713] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Liquid crystals are interesting linear and nonlinear optical materials used to make a wide variety of devices beyond flat panel displays. Liquid crystalline materials can be used either as core or as cladding of switchable/reconfigurable waveguides with either an electrical or an optical control or both. In this paper, materials and main device structures of liquid crystals confined in different waveguide geometries are presented using different substrate materials, such as silicon, soda lime or borosilicate glass and polydimethylsiloxane. Modelling of the behaviour of liquid crystal nanometric molecular reorientation and related refractive index distribution under both low-frequency electric and intense optical fields is reported considering optical anisotropy of liquid crystals. A few examples of integrated optic devices based on waveguides using liquid crystalline materials as core for optical switching and filtering are reviewed. Reported results indicate that low-power control signals represent a significant feature of photonic devices based on light propagation in liquid crystals, with performance, which are competitive with analogous integrated optic devices based on other materials for optical communications and optical sensing systems.
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6
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Hole Injection Role of p-Type Conjugated Polymer Nanolayers in Phosphorescent Organic Light-Emitting Devices. ELECTRONICS 2021. [DOI: 10.3390/electronics10182283] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Here, we report the hole injection role of p-type conjugated polymer layer in phosphorescent organic light-emitting devices (OLEDs). Poly(3-hexylthiophene) (P3HT) nanolayers (thickness = ~1 nm thick), which were subjected to thermal annealing at 140 °C by varying annealing time, were inserted between indium tin oxide (ITO) anodes and hole transport layers (N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-benzidine, NPB). The 1 nm-thick P3HT layers showed very weak absorption in the visible light range of 500~650 nm. The device results disclosed that the presence of P3HT layers were just able to improve the charge injection of OLEDs leading to an enhanced luminance irrespective of thermal annealing condition. The highest luminance and efficiency were achieved for the OLEDs with the P3HT layers annealed at 140 °C for 10 min. Further annealing for 30 min resulted in turn-down of device performances. The emission color was almost unchanged by the presence of P3HT layers even though the color coordinates were marginally fluctuated according to the annealing time. The present result delivers the possibility to use p-type conjugated polymers (i.e., P3HT) as a hole injection layer in OLEDs.
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7
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Sutherland GA, Polak D, Swainsbury DJK, Wang S, Spano FC, Auman DB, Bossanyi DG, Pidgeon JP, Hitchcock A, Musser AJ, Anthony JE, Dutton PL, Clark J, Hunter CN. A Thermostable Protein Matrix for Spectroscopic Analysis of Organic Semiconductors. J Am Chem Soc 2020; 142:13898-13907. [PMID: 32672948 DOI: 10.1021/jacs.0c05477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Advances in protein design and engineering have yielded peptide assemblies with enhanced and non-native functionalities. Here, various molecular organic semiconductors (OSCs), with known excitonic up- and down-conversion properties, are attached to a de novo-designed protein, conferring entirely novel functions on the peptide scaffolds. The protein-OSC complexes form similarly sized, stable, water-soluble nanoparticles that are robust to cryogenic freezing and processing into the solid-state. The peptide matrix enables the formation of protein-OSC-trehalose glasses that fix the proteins in their folded states under oxygen-limited conditions. The encapsulation dramatically enhances the stability of protein-OSC complexes to photodamage, increasing the lifetime of the chromophores from several hours to more than 10 weeks under constant illumination. Comparison of the photophysical properties of astaxanthin aggregates in mixed-solvent systems and proteins shows that the peptide environment does not alter the underlying electronic processes of the incorporated materials, exemplified here by singlet exciton fission followed by separation into weakly bound, localized triplets. This adaptable protein-based approach lays the foundation for spectroscopic assessment of a broad range of molecular OSCs in aqueous solutions and the solid-state, circumventing the laborious procedure of identifying the experimental conditions necessary for aggregate generation or film formation. The non-native protein functions also raise the prospect of future biocompatible devices where peptide assemblies could complex with native and non-native systems to generate novel functional materials.
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Affiliation(s)
- George A Sutherland
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, U.K
| | - Daniel Polak
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
| | - David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, U.K
| | - Shuangqing Wang
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
| | - Frank C Spano
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Dirk B Auman
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - David G Bossanyi
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
| | - James P Pidgeon
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
| | - Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, U.K
| | - Andrew J Musser
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
| | - John E Anthony
- Department of Chemistry, University of Kentucky, Kentucky 40511, United States
| | - P Leslie Dutton
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jenny Clark
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, U.K
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8
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Ester DF, McKearney D, Herasymchuk K, Williams VE. Heterocycle Effects on the Liquid Crystallinity of Terthiophene Analogues. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E2314. [PMID: 31331059 PMCID: PMC6678929 DOI: 10.3390/ma12142314] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/06/2019] [Accepted: 07/13/2019] [Indexed: 01/01/2023]
Abstract
Liquid crystalline self-assembly offers the potential to create highly ordered, uniformly aligned, and defect-free thin-film organic semiconductors. Analogues of one of the more promising classes of liquid crystal semiconductors, 5,5"-dialkyl-α-terthiophenes, were prepared in order to investigate the effects of replacing the central thiophene with either an oxadiazole or a thiadiazole ring. The phase behaviour was examined by differential scanning calorimetry, polarized optical microscopy, and variable temperature x-ray diffraction. While the oxadiazole derivative was not liquid crystalline, thiadiazole derivatives formed smectic C and soft crystal lamellar phases, and maintained lamellar order down to room temperature. Variation of the terminal alkyl chains also influenced the observed phase sequence. Single crystal structures revealed the face-to-face orientation of molecules within the layers in the solid-state, a packing motif that is rationalized based on the shape and dipole of the thiadiazole ring, as corroborated by density functional theory (DFT) calculations. The solution opto-electronic properties of the systems were characterized by absorption and emission spectroscopy, cyclic voltammetry, and time-dependent density functional theory (TD-DFT).
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Affiliation(s)
- David F Ester
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Declan McKearney
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Khrystyna Herasymchuk
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Vance E Williams
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada.
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9
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Xu X, Deng W, Zhang X, Huang L, Wang W, Jia R, Wu D, Zhang X, Jie J, Lee ST. Dual-Band, High-Performance Phototransistors from Hybrid Perovskite and Organic Crystal Array for Secure Communication Applications. ACS NANO 2019; 13:5910-5919. [PMID: 31067403 DOI: 10.1021/acsnano.9b01734] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
High-performance phototransistors made from organic semiconductor single crystals (OSSCs) have attracted much attention due to the high responsivity and solution-processing capability of OSSCs. However, OSSC-based phototransistors capable of dual-band spectral response remain a difficult challenge to achieve because organic semiconductors usually possess only narrow single-band absorption. Here, we report the fabrication of high-performance, dual-band phototransistors from a hybrid structure of a 2,7-dioctyl[1]benzothieno[3,2- b][1]benzothiophene (C8-BTBT) single-crystal array coated with CH3NH3PbI3 nanoparticles (NPs) synthesized by a simple, one-step solution method. In contrast to C8-BTBT and CH3NH3PbI3 NPs with respective absorption in the ultraviolet (UV) and visible (vis) region, their hybrid structure shows broad absorption covering the entire UV-vis range. The hybrid-based phototransistors exhibit an ultrahigh responsivity of >1.72 × 104 A/W in the 252-780 nm region, which represents the best performance for solution-processing, broadband photodetectors. Moreover, integrated phototransistor circuitries from the hybrid CH3NH3PbI3 NPs/C8-BTBT single-crystal array show applications for high-security communication.
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Affiliation(s)
- Xiuzhen Xu
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou , Jiangsu 215000 , People's Republic of China
| | - Wei Deng
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou , Jiangsu 215000 , People's Republic of China
| | - Xiujuan Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou , Jiangsu 215000 , People's Republic of China
| | - Liming Huang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou , Jiangsu 215000 , People's Republic of China
| | - Wei Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou , Jiangsu 215000 , People's Republic of China
| | - Ruofei Jia
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou , Jiangsu 215000 , People's Republic of China
| | - Di Wu
- School of Physics and Engineering and Key Laboratory of Material Physics, Ministry of Education , Zhengzhou University , Zhengzhou , Henan 450052 , People's Republic of China
| | - Xiaohong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou , Jiangsu 215000 , People's Republic of China
| | - Jiansheng Jie
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou , Jiangsu 215000 , People's Republic of China
| | - Shuit-Tong Lee
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou , Jiangsu 215000 , People's Republic of China
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10
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Zhang C, Gao M, Ribeiro de Almeida RR, Weissflog W, Lavrentovich OD, Jákli A. Polarization-Modulated Bent-Core Liquid Crystal Thin Films without Layer Undulation. PHYSICAL REVIEW LETTERS 2019; 122:137801. [PMID: 31012615 DOI: 10.1103/physrevlett.122.137801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Indexed: 06/09/2023]
Abstract
Spatial confinement is known to affect molecular organizations of soft matter. We present an important manifestation of this statement for thin films of bent-core smectic liquid crystals. Prior freeze-fracture transmission electron microscopy (FFTEM) studies carried out on nitro-substituted bent-core mesogens (n-OPIMB-NO_{2}) revealed an undulated smectic layer structure with an undulation periodicity of ∼8 nm. We report cryogenic TEM measurements on ∼100 nm thick 8-OPIMB-NO_{2} films. In contrast to FFTEM results, our studies show only density modulation with periodicity b=16.2 nm, and no smectic layer undulation. We show that the discrepancy between the FFTEM and cryogenic transmission electron microscopy (cryo-TEM) results can be attributed to the different sample thicknesses used in the experiments. FFTEM monitors cracked surfaces of a relatively thick (5-10 μm) frozen sample, whereas cryo-TEM visualizes the volume of a thin (0.1 μm) film that was quenched from its partially fluid phase. These results have importance in possible photovoltaics and organic electronics applications where submicron thin films are used.
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Affiliation(s)
- Cuiyu Zhang
- Chemical Physics Interdisciplinary Program and Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA
| | - Min Gao
- Chemical Physics Interdisciplinary Program and Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA
| | - R R Ribeiro de Almeida
- Chemical Physics Interdisciplinary Program and Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA
- Department of Physics, Federal University of Technology, Apucarana, PR 86812-460, Brazil
| | - Wolfgang Weissflog
- Martin Luther University Halle-Wittenberg, Department of Chemistry, Physical Chemistry, von-Danckelmann-Platz 4, 06120 Halle, Germany
| | - Oleg D Lavrentovich
- Chemical Physics Interdisciplinary Program and Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA
- Department of Physics, Kent State University, Kent, Ohio 44242, USA
| | - Antal Jákli
- Chemical Physics Interdisciplinary Program and Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA
- Department of Physics, Kent State University, Kent, Ohio 44242, USA
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11
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Liu C, Zhang X, Pan X, Yang G. Unveiling the Photophysical Properties of Boron Heptaaryldipyrromethene Derivatives. Chemphyschem 2018; 19:2751-2757. [PMID: 29992730 DOI: 10.1002/cphc.201800452] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Indexed: 12/27/2022]
Abstract
Increased interest has been devoted to the discovery of multifunctional materials with desirable properties, as continuous performance enhancement of various devices mainly depends on high-performance materials. Now, density functional theory has become a powerful tool to design new materials and rationalize experimental observations. In this work, we explored the photophysical properties origin of chiral boron heptaaryldipyrromethene (heptaaryl-BODIPY), which has charming optoelectronic properties. At the same time, we designed the other five compounds on the basis of heptaaryl-BODIPY. The simulated electronic absorption and emission spectra of heptaaryl-BODIPY are in agreement with experimental ones, allowing us to reliably assign its electronic transition property. The designed compound 6 shows remarkably large first hyperpolarizability value up to 82.78×10-30 esu. For this kind of compounds, their NLO response values associate with not only position but also electronic nature of substituent groups. Moreover, electron reorganization energies of compounds 1-4 are comparable to tris(8-hydroxyquinolinato)aluminium(III) which is a typical electron transport material. Intriguingly, the studied compounds are the excellent fluorescent probe materials from the standpoint of large Stokes shift and high emission efficiency. Our work enables an opportunity for understanding the relationship between microelectronic structure and macroscopic performance of BODIPY derivatives.
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Affiliation(s)
- Chunyu Liu
- Institute of Functional Material Chemistry, National & Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Xue Zhang
- Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, National Demonstration Center for Experimental Physics Education, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Xiumei Pan
- Institute of Functional Material Chemistry, National & Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Guochun Yang
- Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, National Demonstration Center for Experimental Physics Education, Northeast Normal University, Changchun, 130024, Jilin, China
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