1
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Wang CI, Maier JC, Jackson NE. Accessing the electronic structure of liquid crystalline semiconductors with bottom-up electronic coarse-graining. Chem Sci 2024; 15:8390-8403. [PMID: 38846409 PMCID: PMC11151863 DOI: 10.1039/d3sc06749a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 05/01/2024] [Indexed: 06/09/2024] Open
Abstract
Understanding the relationship between multiscale morphology and electronic structure is a grand challenge for semiconducting soft materials. Computational studies aimed at characterizing these relationships require the complex integration of quantum-chemical (QC) calculations, all-atom and coarse-grained (CG) molecular dynamics simulations, and back-mapping approaches. However, these methods pose substantial computational challenges that limit their application to the requisite length scales of soft material morphologies. Here, we demonstrate the bottom-up electronic coarse-graining (ECG) of morphology-dependent electronic structure in the liquid-crystal-forming semiconductor, 2-(4-methoxyphenyl)-7-octyl-benzothienobenzothiophene (BTBT). ECG is applied to construct density functional theory (DFT)-accurate valence band Hamiltonians of the isotropic and smectic liquid crystal (LC) phases using only the CG representation of BTBT. By bypassing the atomistic resolution and its prohibitive computational costs, ECG enables the first calculations of the morphology dependence of the electronic structure of charge carriers across LC phases at the ∼20 nm length scale, with robust statistical sampling. Kinetic Monte Carlo (kMC) simulations reveal a strong morphology dependence on zero-field charge mobility among different LC phases as well as the presence of two-molecule charge carriers that act as traps and hinder charge transport. We leverage these results to further evaluate the feasibility of developing mesoscopic, field-based ECG models in future works. The fully CG approach to electronic property predictions in LC semiconductors opens a new computational direction for designing electronic processes in soft materials at their characteristic length scales.
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Affiliation(s)
- Chun-I Wang
- Department of Chemistry, University of Illinois at Urbana-Champaign 505 S Mathews Avenue Urbana Illinois 61801 USA
| | - J Charlie Maier
- Department of Chemistry, University of Illinois at Urbana-Champaign 505 S Mathews Avenue Urbana Illinois 61801 USA
| | - Nicholas E Jackson
- Department of Chemistry, University of Illinois at Urbana-Champaign 505 S Mathews Avenue Urbana Illinois 61801 USA
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2
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Ni F, Huang Y, Qiu L, Yang C. Synthetic progress of organic thermally activated delayed fluorescence emitters via C-H activation and functionalization. Chem Soc Rev 2024; 53:5904-5955. [PMID: 38717257 DOI: 10.1039/d3cs00871a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Thermally activated delayed fluorescence (TADF) emitters have become increasingly prominent due to their promising applications across various fields, prompting a continuous demand for developing reliable synthetic methods to access them. This review aims to highlight the progress made in the last decade in synthesizing organic TADF compounds through C-H bond activation and functionalization. The review begins with a brief introduction to the basic features and design principles of TADF emitters. It then provides an overview of the advantages and concise development of C-H bond transformations in constructing TADF emitters. Subsequently, it summarizes both transition-metal-catalyzed and non-transition-metal-promoted C-H bond transformations used for the synthesis of TADF emitters. Finally, the review gives an outlook on further challenges and potential directions in this field.
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Affiliation(s)
- Fan Ni
- National Engineering Lab of Special Display Technology, State Key Lab of Advanced Display Technology, Academy of Opto-Electronic Technology, Intelligent Interconnected Systems Laboratory of Anhui, Anhui Province Key Laboratory of Measuring Theory and Precision Instrument, School of Instrument Science and Optoelectronic Engineering, Hefei University of Technology, Hefei, Anhui 230009, P. R. China.
| | - Yipan Huang
- National Engineering Lab of Special Display Technology, State Key Lab of Advanced Display Technology, Academy of Opto-Electronic Technology, Intelligent Interconnected Systems Laboratory of Anhui, Anhui Province Key Laboratory of Measuring Theory and Precision Instrument, School of Instrument Science and Optoelectronic Engineering, Hefei University of Technology, Hefei, Anhui 230009, P. R. China.
| | - Longzhen Qiu
- National Engineering Lab of Special Display Technology, State Key Lab of Advanced Display Technology, Academy of Opto-Electronic Technology, Intelligent Interconnected Systems Laboratory of Anhui, Anhui Province Key Laboratory of Measuring Theory and Precision Instrument, School of Instrument Science and Optoelectronic Engineering, Hefei University of Technology, Hefei, Anhui 230009, P. R. China.
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, Guangdong 518060, P. R. China.
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3
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Mandal B, Mandal S, Halder S, Adhikari D. Photocatalytic α-arylation of cyclic ketones by a thermally activated delayed fluorescence molecule. Chem Commun (Camb) 2024; 60:5852-5855. [PMID: 38752485 DOI: 10.1039/d4cc01287a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
α-Arylation of cyclic ketones via an organophotocatalytic route has been described utilizing PXZ-TRZ, a molecule displaying thermally activated delayed fluorescence (TADF). Using this route, a plethora of cyclic ketones including cyclohexanone, cyclopentanone and even cyclooctanone can be effectively arylated with many aryl iodides or bromides under mild conditions.
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Affiliation(s)
- Baishanal Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector-81, Knowledge City, Manauli-140306, India.
| | - Sourav Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector-81, Knowledge City, Manauli-140306, India.
| | - Supriya Halder
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector-81, Knowledge City, Manauli-140306, India.
| | - Debashis Adhikari
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector-81, Knowledge City, Manauli-140306, India.
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4
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Roy R, Brouillac C, Jacques E, Quinton C, Poriel C. π-Conjugated Nanohoops: A New Generation of Curved Materials for Organic Electronics. Angew Chem Int Ed Engl 2024:e202402608. [PMID: 38744668 DOI: 10.1002/anie.202402608] [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: 02/05/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/16/2024]
Abstract
Nanohoops, cyclic association of π-conjugated systems to form a hoop-shaped molecule, have been widely developed in the last 15 years. Beyond the synthetic challenge, the strong interest towards these molecules arises from their radially oriented π-orbitals, which provide singular properties to these fascinating structures. Thanks to their particular cylindrical arrangement, this new generation of curved molecules have been already used in many applications such as host-guest complexation, biosensing, bioimaging, solid-state emission and catalysis. However, their potential in organic electronics has only started to be explored. From the first incorporation as an emitter in a fluorescent organic light emitting diode (OLED), to the recent first incorporation as a host in phosphorescent OLEDs or as charge transporter in organic field-effect transistors and in organic photovoltaics, this field has shown important breakthroughs in recent years. These findings have revealed that curved materials can play a key role in the future and can even be more efficient than their linear counterparts. This can have important repercussions for the future of electronics. Time has now come to overview the different nanohoops used to date in electronic devices in order to stimulate the future molecular designs of functional materials based on these macrocycles.
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Affiliation(s)
- Rupam Roy
- Univ Rennes, CNRS, ISCR-UMR CNRS 6226, F-35000, Rennes, France
- Department of Chemistry, University of Florida, Gainesville, Florida, United States, 32603
| | | | | | | | - Cyril Poriel
- Univ Rennes, CNRS, ISCR-UMR CNRS 6226, F-35000, Rennes, France
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5
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Gao Y, Wang Y, Guo Z, Wan Y, Xue Z, Han Y, Yang W, Ma X. Ultrafast photophysics of an orange-red thermally activated delayed fluorescence emitter: the role of external structural restraint. Chem Sci 2024; 15:6410-6420. [PMID: 38699269 PMCID: PMC11062098 DOI: 10.1039/d4sc00460d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/21/2024] [Indexed: 05/05/2024] Open
Abstract
The application of thermally activated delay fluorescence (TADF) emitters in the orange-red regime usually suffers from the fast non-radiative decay of emissive singlet states (kSNR), leading to low emitting efficiency in corresponding organic light-emitting diode (OLED) devices. Although kSNR has been quantitatively described by energy gap law, how ultrafast molecular motions are associated with the kSNR of TADF emitters remains largely unknown, which limits the development of new strategies for improving the emitting efficiency of corresponding OLED devices. In this work, we employed two commercial TADF emitters (TDBA-Ac and PzTDBA) as a model system and attempted to clarify the relationship between ultrafast excited-state structural relaxation (ES-SR) and kSNR. Spectroscopic and theoretical investigations indicated that S1/S0 ES-SR is directly associated with promoting vibrational modes, which are considerably involved in electronic-vibrational coupling through the Huang-Rhys factor, while kSNR is largely affected by the reorganization energy of the promoting modes. By restraining S1/S0 ES-SR in doping films, the kSNR of TADF emitters can be greatly reduced, resulting in high emitting efficiency. Therefore, by establishing the connection among S1/S0 ES-SR, promoting modes and kSNR of TADF emitters, our work clarified the key role of external structural restraint for achieving high emitting efficiency in TADF-based OLED devices.
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Affiliation(s)
- Yixuan Gao
- Institute of Molecular Plus, Tianjin University Tianjin 300072 P. R. China
| | - Yaxin Wang
- Institute of Molecular Plus, Tianjin University Tianjin 300072 P. R. China
| | - Zilong Guo
- Institute of Molecular Plus, Tianjin University Tianjin 300072 P. R. China
| | - Yan Wan
- College of Chemistry, Beijing Normal University Beijing 100875 P. R. China
| | - Zheng Xue
- Engineering Research Center for Nanomaterials, Henan University Kaifeng 475004 P. R. China
| | - Yandong Han
- Engineering Research Center for Nanomaterials, Henan University Kaifeng 475004 P. R. China
| | - Wensheng Yang
- Institute of Molecular Plus, Tianjin University Tianjin 300072 P. R. China
- Engineering Research Center for Nanomaterials, Henan University Kaifeng 475004 P. R. China
| | - Xiaonan Ma
- Institute of Molecular Plus, Tianjin University Tianjin 300072 P. R. China
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6
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Govindharaj P, Wierzba AJ, Kęska K, Kochman MA, Wiosna-Sałyga G, Kubas A, Data P, Lindner M. Regioisomerism vs Conformation: Impact of Molecular Design on the Emission Pathway in Organic Light-Emitting Device Emitters. ACS APPLIED MATERIALS & INTERFACES 2024; 16. [PMID: 38668584 PMCID: PMC11082840 DOI: 10.1021/acsami.3c19212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/14/2024] [Accepted: 04/17/2024] [Indexed: 05/12/2024]
Abstract
Despite the design and proposal of several new structural motifs as thermally activated delayed fluorescent (TADF) emitters for organic light-emitting device (OLED) applications, the nature of their interaction with the host matrix in the emissive layer of the device and their influence on observed photophysical outputs remain unclear. To address this issue, we present, for the first time, the use of up to four regioisomers bearing a donor-acceptor-donor electronic structure based on the desymmetrized naphthalene benzimidazole scaffold, equipped with various electron-donating units and possessing distinguished conformational lability. Quantum chemical calculations allow us to identify the most favorable conformations adopted by the electron-rich groups across the entire pool of regioisomers. These conformations were then compared with conformational changes caused by the interaction of the emitter with the Zeonex and 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP) matrices, and the correlation with observed photophysics was monitored by UV-vis absorption and steady-state photoluminescence spectra, combined with time-resolved spectroscopic techniques. Importantly, a CBP matrix was found to have a significant impact on the conformational change of regioisomers, leading to unique TADF emission mechanisms that encompass dual emission and inversion of the singlet-triplet excited-state energies and result in the enhancement of TADF efficiency. As a proof of concept, regioisomers with optimal donor positions were utilized to fabricate an OLED, revealing, with the best-performing dye, an external quantum emission of 11.6%, accompanied by remarkable luminance (28,000 cd/m2). These observations lay the groundwork for a better understanding of the role of the host matrix. In the long term, this new knowledge can lead to predicting the influence of the host matrix and adopting the structure of the emitter in a way that allows the development of highly efficient and efficient OLEDs.
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Affiliation(s)
- Prasannamani Govindharaj
- Department
of Molecular Physics, Faculty of Chemistry, Łódź University of Technology, Stefana Żeromskiego 114, 90-543 Łódź, Poland
| | - Aleksandra J. Wierzba
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Karolina Kęska
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Michał Andrzej Kochman
- Institute
of Physical Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Gabriela Wiosna-Sałyga
- Department
of Molecular Physics, Faculty of Chemistry, Łódź University of Technology, Stefana Żeromskiego 114, 90-543 Łódź, Poland
| | - Adam Kubas
- Institute
of Physical Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Przemysław Data
- Department
of Molecular Physics, Faculty of Chemistry, Łódź University of Technology, Stefana Żeromskiego 114, 90-543 Łódź, Poland
| | - Marcin Lindner
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
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7
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Di Maiolo F, Phan Huu DKA, Giavazzi D, Landi A, Racchi O, Painelli A. Shedding light on thermally-activated delayed fluorescence. Chem Sci 2024; 15:5434-5450. [PMID: 38638233 PMCID: PMC11023041 DOI: 10.1039/d4sc00033a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 02/17/2024] [Indexed: 04/20/2024] Open
Abstract
Thermally activated delayed fluorescence (TADF) is a hot research topic in view of its impressive applications in a wide variety of fields from organic LEDs to photodynamic therapy and metal-free photocatalysis. TADF is a rare and fragile phenomenon that requires a delicate equilibrium between tiny singlet-triplet gaps, sizable spin-orbit couplings, conformational flexibility and a balanced contribution of charge transfer and local excited states. To make the picture more complex, this precarious equilibrium is non-trivially affected by the interaction of the TADF dye with its local environment. The concurrent optimization of the dye and of the embedding medium is therefore of paramount importance to boost practical applications of TADF. Towards this aim, refined theoretical and computational approaches must be cleverly exploited, paying attention to the reliability of adopted approximations. In this perspective, we will address some of the most important issues in the field. Specifically, we will critically review theoretical and computational approaches to TADF rates, highlighting the limits of widespread approaches. Environmental effects on the TADF photophysics are discussed in detail, focusing on the major role played by dielectric and conformational disorder in liquid solutions and amorphous matrices.
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Affiliation(s)
- Francesco Di Maiolo
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
| | - D K Andrea Phan Huu
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
| | - Davide Giavazzi
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
| | - Andrea Landi
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
| | - Ottavia Racchi
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
| | - Anna Painelli
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
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8
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Cho HH, Congrave DG, Gillett AJ, Montanaro S, Francis HE, Riesgo-Gonzalez V, Ye J, Chowdury R, Zeng W, Etherington MK, Royakkers J, Millington O, Bond AD, Plasser F, Frost JM, Grey CP, Rao A, Friend RH, Greenham NC, Bronstein H. Suppression of Dexter transfer by covalent encapsulation for efficient matrix-free narrowband deep blue hyperfluorescent OLEDs. NATURE MATERIALS 2024; 23:519-526. [PMID: 38480865 PMCID: PMC10990937 DOI: 10.1038/s41563-024-01812-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 01/18/2024] [Indexed: 03/21/2024]
Abstract
Hyperfluorescence shows great promise for the next generation of commercially feasible blue organic light-emitting diodes, for which eliminating the Dexter transfer to terminal emitter triplet states is key to efficiency and stability. Current devices rely on high-gap matrices to prevent Dexter transfer, which unfortunately leads to overly complex devices from a fabrication standpoint. Here we introduce a molecular design where ultranarrowband blue emitters are covalently encapsulated by insulating alkylene straps. Organic light-emitting diodes with simple emissive layers consisting of pristine thermally activated delayed fluorescence hosts doped with encapsulated terminal emitters exhibit negligible external quantum efficiency drops compared with non-doped devices, enabling a maximum external quantum efficiency of 21.5%. To explain the high efficiency in the absence of high-gap matrices, we turn to transient absorption spectroscopy. It is directly observed that Dexter transfer from a pristine thermally activated delayed fluorescence sensitizer host can be substantially reduced by an encapsulated terminal emitter, opening the door to highly efficient 'matrix-free' blue hyperfluorescence.
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Affiliation(s)
- Hwan-Hee Cho
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Daniel G Congrave
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK.
| | | | - Stephanie Montanaro
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Haydn E Francis
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot, UK
| | - Víctor Riesgo-Gonzalez
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot, UK
| | - Junzhi Ye
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | - Weixuan Zeng
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Marc K Etherington
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Ellison Place, Newcastle upon Tyne, UK
| | - Jeroen Royakkers
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Oliver Millington
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Andrew D Bond
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Felix Plasser
- Department of Chemistry, Loughborough University, Loughborough, UK
| | | | - Clare P Grey
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot, UK
| | - Akshay Rao
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | - Neil C Greenham
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
| | - Hugo Bronstein
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK.
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9
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Li J, Sun X, Dmitrieva E, Israel N, Wu F, Yang L, Liu R, Feng X, Plietker B. Tosylazide as N1-Synthon: Iron-Catalyzed Nitrogenative Dimerization of Indoles to p-Bisindolopyrazine Derivatives. Org Lett 2024; 26:1046-1050. [PMID: 38294841 DOI: 10.1021/acs.orglett.3c04209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
We present a straightforward one-step process to access a range of novel p-diindolepyrazines via an unprecedented [n-Bu4N][Fe(CO)3(NO)] (TBA[Fe])-catalyzed intermolecular nitrogenative dimerization of various indole derivatives. Remarkably, tosylazide functions as a N1-synthon forming the central pyrazine unit that joins the two indole subunits. The catalytic transformation shows a good substrate scope, and the obtained products show interesting electronic properties.
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Affiliation(s)
- Jianan Li
- Chair of Organic Chemistry I, Faculty of Chemistry and Food Chemistry, TU Dresden, Bergstraße 66, DE-01069 Dresden, Germany
| | - Xiaohan Sun
- Chair of Organic Chemistry I, Faculty of Chemistry and Food Chemistry, TU Dresden, Bergstraße 66, DE-01069 Dresden, Germany
| | - Evgenia Dmitrieva
- Leibniz Institute for Solid State and Materials Research, DE-01069 Dresden, Germany
| | - Noel Israel
- Leibniz Institute for Solid State and Materials Research, DE-01069 Dresden, Germany
| | - Fupeng Wu
- Center for Advancing Electronics Dresden (cfaed), Faculty of Chemistry and Food Chemistry, TU Dresden, Mommsenstrasse 4, DE-01062 Dresden, Germany
- Max Planck Institute of Microstructure Physics Weinberg 2, 06120 Halle, Germany
| | - Lin Yang
- Center for Advancing Electronics Dresden (cfaed), Faculty of Chemistry and Food Chemistry, TU Dresden, Mommsenstrasse 4, DE-01062 Dresden, Germany
| | - Renxiang Liu
- Center for Advancing Electronics Dresden (cfaed), Faculty of Chemistry and Food Chemistry, TU Dresden, Mommsenstrasse 4, DE-01062 Dresden, Germany
| | - Xinliang Feng
- Center for Advancing Electronics Dresden (cfaed), Faculty of Chemistry and Food Chemistry, TU Dresden, Mommsenstrasse 4, DE-01062 Dresden, Germany
- Max Planck Institute of Microstructure Physics Weinberg 2, 06120 Halle, Germany
| | - Bernd Plietker
- Chair of Organic Chemistry I, Faculty of Chemistry and Food Chemistry, TU Dresden, Bergstraße 66, DE-01069 Dresden, Germany
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10
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Wang H, Chen JX, Shi YZ, Zhang X, Zhou L, Hao XY, Yu J, Wang K, Zhang XH. An A-D-A-Type Thermally Activated Delayed Fluorescence Emitter with Intrinsic Yellow Emission Realizing Record-High Red/NIR OLEDs upon Modulating Intermolecular Aggregations. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2307725. [PMID: 37792472 DOI: 10.1002/adma.202307725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/22/2023] [Indexed: 10/06/2023]
Abstract
Realizing efficient red/near-infrared (NIR) electroluminescence (EL) by precisely modulating molecular aggregations of thermally activated delayed fluorescence (TADF) emitters is an attractive pathway, yet the molecular designs are elusive. Here, a new approach is proposed to manage molecular aggregation via a mild-twist acceptor-donor-acceptor (A-D-A)-type molecular design. A proof-of-concept TADF molecule, QCN-PhSAC-QCN, is developed that furnishes a fast radiative rate and obvious aggregation-induced emission feature. Its emission bands can be facilely shifted from intrinsic yellow to the red/NIR region via fine-tuning doping levels and molecular aggregates while maintaining elegant photoluminescence quantum yields benefiting from suppressed exciton annihilation processes. As a result, a QCN-PhSAC-QCN-based organic light-emitting diode (OLED) exhibits a record-setting external quantum efficiency (EQE) of 39.1% at a doping ratio of 10 wt.%, peaking at 620 nm. Moreover, its nondoped NIR OLED affords a champion EQE of 14.3% at 711 nm and retains outstanding EQEs of 5.40% and 2.35% at current densities of 10 and 100 mA cm-2 , respectively, which are the highest values among all NIR-TADF OLEDs at similar density levels. This work validates the feasibility of such mild-twist A-D-A-type molecular design for precisely controlling molecular aggregation while maintaining high efficiency, thus providing a promising pathway for high-performance red/NIR TADF OLEDs.
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Affiliation(s)
- Hui Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Jia-Xiong Chen
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, Guangdong, 510006, P. R. China
| | - Yi-Zhong Shi
- School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou, Jiangsu, 215009, P. R. China
| | - Xi Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Lu Zhou
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Xiao-Yao Hao
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Jia Yu
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Kai Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Xiao-Hong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
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11
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Zhang W, Ma Y, Song H, Miao R, Kong J, Zhou M. Deciphering the photophysical properties of naphthalimide derivatives using ultrafast spectroscopy. Phys Chem Chem Phys 2024; 26:4607-4613. [PMID: 38251277 DOI: 10.1039/d3cp05654f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
Naphthalimide derivatives composed of donor-acceptor type structures hold significant promise across a wide range of applications. Here, the solvent polarity and viscosity controlled excited-state dynamics of a naphthalimide derivative with a donor-acceptor structure were studied using multiple spectroscopic techniques. From the stationary spectroscopic investigations, large Stokes shift and low fluorescence quantum yield were observed with increasing the solvent polarity, suggesting a more polar excited state relative to the ground state, which is evidenced by the Lippert-Mataga relationship. We also observe an enhanced fluorescence with a prolonged lifetime in a more viscous solution due to the restriction of excited-state molecular rearrangement. These observations result from the emerged twisted intramolecular charge transfer (TICT) state. The ultrafast spectroscopy studies further unravel a solvent polarity dependent excited state evolution from the intramolecular charge transfer state to the TICT state, revealing that the TICT state can be populated only in strong polar solvents. Control experiments by tuning the solvent viscosity in ultrafast experiments were employed to verify the excited state molecular rearrangement subsequently. These observations collectively emphasize how fine-tuning the photophysical properties of naphthalimide derivatives can be achieved through strategic manipulation of solvent polarity and viscosity.
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Affiliation(s)
- Wei Zhang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026, China.
| | - Yalei Ma
- Laboratory of Applied Surface and Colloids Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, P. R. China.
| | - Hongwei Song
- Department of Chemistry-Angstrom Laboratory, Uppsala University, Box 523, Uppsala 75120, Sweden
| | - Rong Miao
- Laboratory of Applied Surface and Colloids Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, P. R. China.
| | - Jie Kong
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026, China.
| | - Meng Zhou
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026, China.
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12
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Avula S, Jhun BH, Jo U, Heo S, Lee JY, You Y. Achieving Long-Wavelength Electroluminescence Using Two-Coordinate Gold(I) Complexes: Overcoming the Energy Gap Law. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2305745. [PMID: 37953418 PMCID: PMC10767458 DOI: 10.1002/advs.202305745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/05/2023] [Indexed: 11/14/2023]
Abstract
Two-coordinate coinage metal complexes have emerged as promising emitters for highly efficient organic light-emitting devices (OLEDs). However, achieving efficient long-wavelength electroluminescence emission from these complexes remains as a daunting challenge. To address this challenge, molecular design strategies aimed at bolstering the photoluminescence quantum yield (Φ) of Au(I) complex emitters in low-energy emission regions are investigated. By varying amido ligands, a series of two-coordinate Au(I) complexes is developed that exhibit photoluminescence peak wavelengths over a broad range of 533-750 nm. These complexes, in particular, maintain Φ values up to 10% even in the near-infrared emission region, overcoming the constraints imposed by an energy gap. Quantum chemical calculations and photophysical analyses reveal the action of radiative control, which serves to overcome the energy gap law, becomes more pronounced as the overlap between hole and electron distributions (Sr (r)) in the excited state increases. It is further elucidated that Sr (r) increases with the distance between the hole-distribution centroid and the nitrogen atom in an amido ligand. Finally, multilayer OLEDs involving the Au(I) complex emitters exhibit performances beyond the borderline of the electroluminescence wavelength-external quantum efficiency space set by previous devices of coinage metal complexes.
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Affiliation(s)
- Sreenivas Avula
- Department of Chemical and Biomolecular EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Byung Hak Jhun
- Department of Chemical and Biomolecular EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Unhyeok Jo
- School of Chemical EngineeringSungkyunkwan UniversitySuwonGyeonggi‐do16419Republic of Korea
| | - Seunga Heo
- Division of Chemical Engineering and Materials ScienceEwha Womans UniversitySeoul03760Republic of Korea
| | - Jun Yeob Lee
- School of Chemical EngineeringSungkyunkwan UniversitySuwonGyeonggi‐do16419Republic of Korea
| | - Youngmin You
- Department of Chemical and Biomolecular EngineeringYonsei UniversitySeoul03722Republic of Korea
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13
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Naveen KR, Konidena RK, Keerthika P. Neoteric Advances in Oxygen Bridged Triaryl Boron-based Delayed Fluorescent Materials for Organic Light Emitting Diodes. CHEM REC 2023; 23:e202300208. [PMID: 37555789 DOI: 10.1002/tcr.202300208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/17/2023] [Indexed: 08/10/2023]
Abstract
Since their first demonstration, thermally activated delayed fluorescence (TADF) materials have been emerged as the most promising emitters because of their promising applications in optoelectronics, typified by organic light-emitting diodes (OLEDs). In which, the rigid oxygen bridged boron acceptor-featured (DOBNA) emitters have gained tremendous impetus for OLEDs, which is ascribed to their excellent external quantum efficiency (EQE). However, these materials often displayed severe efficiency roll-off and poor operational stability. Therefore, there needs to be a comprehensive understanding of the aspect of the molecular design and structure-property relationship. To the best of our knowledge, there is no detailed review on the structure-function outlook of DOBNA-based emitters emphasizing the effect of the nature of donor units, their number density, and substitution pattern on the physicochemical properties, excited state dynamics and OLED performance were reported. To fill this gap, herein we presented the recent advancements in DOBNA-based acceptor featured TADF materials by classifying them into several subgroups based on the molecular design i. e. donor-acceptor (D-A), D-A-D, A-D-A, and multi-resonant TADF (MR-TADF) emitters. The detailed design concepts, along with their respective physicochemical and OLED performances were summarized. Finally, the prospective of this class of materials in forthcoming OLED displays is also discussed.
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Affiliation(s)
- Kenkera Rayappa Naveen
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Rajendra Kumar Konidena
- Department of Chemistry, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur campus, Chennai, Tamil Nadu, 603203, India
| | - P Keerthika
- Department of Chemistry, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur campus, Chennai, Tamil Nadu, 603203, India
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14
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Nguyen TH, Le KM, Nguyen LH, Truong TN. Atom-Based Machine Learning Model for Quantitative Property-Structure Relationship of Electronic Properties of Fusenes and Substituted Fusenes. ACS OMEGA 2023; 8:38441-38451. [PMID: 37867641 PMCID: PMC10586267 DOI: 10.1021/acsomega.3c05212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/15/2023] [Indexed: 10/24/2023]
Abstract
This study presents the development of machine-learning-based quantitative structure-property relationship (QSPR) models for predicting electron affinity, ionization potential, and band gap of fusenes from different chemical classes. Three variants of the atom-based Weisfeiler-Lehman (WL) graph kernel method and the machine learning model Gaussian process regressor (GPR) were used. The data pool comprises polycyclic aromatic hydrocarbons (PAHs), thienoacenes, cyano-substituted PAHs, and nitro-substituted PAHs computed with density functional theory (DFT) at the B3LYP-D3/6-31+G(d) level of theory. The results demonstrate that the GPR/WL kernel methods can accurately predict the electronic properties of PAHs and their derivatives with root-mean-square deviations of 0.15 eV. Additionally, we also demonstrate the effectiveness of the active learning protocol for the GPR/WL kernel methods pipeline, particularly for data sets with greater diversity. The interpretation of the model for contributions of individual atoms to the predicted electronic properties provides reasons for the success of our previous degree of π-orbital overlap model.
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Affiliation(s)
- Tuan H. Nguyen
- Faculty
of Chemical Engineering, Ho Chi Minh City
University of Technology, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City 7000000, Vietnam
| | - Khang M. Le
- Faculty
of Chemistry, VNUHCM-University of Science, 227 Nguyen Van Cu Street, Ho Chi Minh City 700000, Vietnam
| | - Lam H. Nguyen
- Faculty
of Chemistry, VNUHCM-University of Science, 227 Nguyen Van Cu Street, Ho Chi Minh City 700000, Vietnam
- Institute
for Computational Science and Technology, Ho Chi Minh City 700000, Vietnam
| | - Thanh N. Truong
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
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15
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Zhang T, Xiao Y, Wang H, Kong S, Huang R, Ka-Man Au V, Yu T, Huang W. Highly Twisted Thermally Activated Delayed Fluorescence (TADF) Molecules and Their Applications in Organic Light-Emitting Diodes (OLEDs). Angew Chem Int Ed Engl 2023; 62:e202301896. [PMID: 37288654 DOI: 10.1002/anie.202301896] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 06/07/2023] [Accepted: 06/07/2023] [Indexed: 06/09/2023]
Abstract
Thermally activated delayed fluorescence (TADF) materials have attracted great potential in the field of organic light-emitting diodes (OLEDs). Among thousands of TADF materials, highly twisted TADF emitters have become a hotspot in recent years. Compared with traditional TADF materials, highly twisted TADF emitters tend to show multi-channel charge-transfer characters and form rigid molecular structures. This is advantageous for TADF materials, as non-radiative decay processes can be suppressed to facilitate efficient exciton utilization. Accordingly, OLEDs with excellent device performances have also been reported. In this Review, we have summarized recent progress in highly twisted TADF materials and related devices, and give an overview of the molecular design strategies, photophysical studies, and the performances of OLED devices. In addition, the challenges and perspectives of highly twisted TADF molecules and the related OLEDs are also discussed.
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Affiliation(s)
- Tiantian Zhang
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, 127 West Youyi Road, 710072, Xi'an, China
| | - Yuxin Xiao
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, 127 West Youyi Road, 710072, Xi'an, China
| | - Hailan Wang
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, 127 West Youyi Road, 710072, Xi'an, China
| | - Shuting Kong
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, 127 West Youyi Road, 710072, Xi'an, China
| | - Rongjuan Huang
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, 127 West Youyi Road, 710072, Xi'an, China
| | - Vonika Ka-Man Au
- Department of Science and Environmental Studies, The Education University of Hong Kong, 10 Lo Ping Road, Tai Po, New Territories, Hong Kong, China
| | - Tao Yu
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, 127 West Youyi Road, 710072, Xi'an, China
- Key Laboratory of Flexible Electronics of Zhejiang Province, Ningbo Institute of Northwestern Polytechnical University, 218 Qingyi Road, 315103, Ningbo, China
| | - Wei Huang
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, 127 West Youyi Road, 710072, Xi'an, China
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, 211816, Nanjing, China
- State Key Laboratory of Organic Electronics and Information Displays &, Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, 210023, Nanjing, China
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16
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Dreuw A, Hoffmann M. The inverted singlet-triplet gap: a vanishing myth? Front Chem 2023; 11:1239604. [PMID: 37577065 PMCID: PMC10413108 DOI: 10.3389/fchem.2023.1239604] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 07/12/2023] [Indexed: 08/15/2023] Open
Abstract
Molecules with an inverted singlet-triplet gap (STG) between the first excited singlet and triplet states, for example, heptazine, have recently been reported and gained substantial attention since they violate the famous Hund's rule. Utilizing state-of-the-art high-level ab initio methods, the singlet-triplet gap vanishes and approaches zero from below whatever is improved in the theoretical description of the molecules: the basis set or the level of electron correlation. Seemingly, the phenomenon of inverted singlet-triplet gaps tends to vanish the closer we observe.
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Affiliation(s)
- Andreas Dreuw
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Heidelberg, Germany
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17
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Cao L, Liu X, Zhang X, Zhao J, Yu F, Wan Y. The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads. Beilstein J Org Chem 2023; 19:1028-1046. [PMID: 37497052 PMCID: PMC10366440 DOI: 10.3762/bjoc.19.79] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 07/07/2023] [Indexed: 07/28/2023] Open
Abstract
A series of 1,8-naphthalimide (NI)-phenothiazine (PTZ) electron donor-acceptor dyads were prepared to study the thermally activated delayed fluorescence (TADF) properties of the dyads, from a point of view of detection of the various transient species. The photophysical properties of the dyads were tuned by changing the electron-donating and the electron-withdrawing capability of the PTZ and NI moieties, respectively, by oxidation of the PTZ unit, or by using different aryl substituents attached to the NI unit. This tuning effect was manifested in the UV-vis absorption and fluorescence emission spectra, e.g., in the change of the charge transfer absorption bands. TADF was observed for the dyads containing the native PTZ unit, and the prompt and delayed fluorescence lifetimes changed with different aryl substituents on the imide part. In polar solvents, no TADF was observed. For the dyads with the PTZ unit oxidized, no TADF was observed as well. Femtosecond transient absorption spectra showed that the charge separation takes ca. 0.6 ps, and admixtures of locally excited (3LE) state and charge separated (1CS/3CS) states formed (in n-hexane). The subsequent charge recombination from the 1CS state takes ca. 7.92 ns. Upon oxidation of the PTZ unit, the beginning of charge separation is at 178 fs and formation of 3LE state takes 4.53 ns. Nanosecond transient absorption (ns-TA) spectra showed that both 3CS and 3LE states were observed for the dyads showing TADF, whereas only 3LE or 3CS states were observed for the systems lacking TADF. This is a rare but unambiguous experimental evidence that the spin-vibronic coupling of 3CS/3LE states is crucial for TADF. Without the mediating effect of the 3LE state, no TADF is resulted, even if the long-lived 3CS state is populated (lifetime τCS ≈ 140 ns). This experimental result confirms the 3CS → 1CS reverse intersystem crossing (rISC) is slow, without coupling with an approximate 3LE state. These studies are useful for an in-depth understanding of the photophysical mechanisms of the TADF emitters, as well as for molecular structure design of new electron donor-acceptor TADF emitters.
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Affiliation(s)
- Liyuan Cao
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, P. R. China
| | - Xi Liu
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Xue Zhang
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, P. R. China
| | - Jianzhang Zhao
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, 2 Ling Gong Road, Dalian, 116024, P. R. China
| | - Fabiao Yu
- Key Laboratory of Hainan Trauma and Disaster Rescue, The First Affiliated Hospital of Hainan Medical University, Hainan Medical University, Haikou 571199, P. R. China
| | - Yan Wan
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
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18
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Asanuma D, Minh Nguyen HT, Liu Z, Tojo S, Shigemitsu H, Yamaji M, Kawai K, Mori T, Kida T, Pratx G, Fujitsuka M, Osakada Y. Radioluminescence from polymer dots based on thermally activated delayed fluorescence. NANOSCALE ADVANCES 2023; 5:3424-3427. [PMID: 37383072 PMCID: PMC10295164 DOI: 10.1039/d3na00308f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 05/22/2023] [Indexed: 06/30/2023]
Abstract
We demonstrate that polymer dots doped with thermally activated delayed fluorescence (TADF) molecules clearly exhibit blue radio-luminescence upon hard X-ray and electron beam irradiation, which is a new design for nano-sized scintillators.
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Affiliation(s)
- Daiki Asanuma
- SANKEN, Osaka University Mihogaoka 8-1, Ibaraki Osaka 567-0047 Japan
| | - Hieu Thi Minh Nguyen
- Department of Radiation Oncology and Medical Physics, Stanford University 300 Pasteur Dr. Stanford CA 94305 USA
| | - Zuoyue Liu
- SANKEN, Osaka University Mihogaoka 8-1, Ibaraki Osaka 567-0047 Japan
| | - Sachiko Tojo
- SANKEN, Osaka University Mihogaoka 8-1, Ibaraki Osaka 567-0047 Japan
| | - Hajime Shigemitsu
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University 2-1 Yamadaoka, Suita Osaka 565-0871 Japan
| | - Minoru Yamaji
- Division of Molecular Science, Graduate School of Science and Engineering, Gunma University Ota Gunma 373-0057 Japan
| | - Kiyohiko Kawai
- SANKEN, Osaka University Mihogaoka 8-1, Ibaraki Osaka 567-0047 Japan
- Department of Life Science and Technology, Tokyo Institute of Technology B-52, 4259 Nagatsuta, Midori-ku Yokohama Kanagawa 226-8501 Japan
| | - Tadashi Mori
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University 2-1 Yamadaoka, Suita Osaka 565-0871 Japan
| | - Toshiyuki Kida
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University 2-1 Yamadaoka, Suita Osaka 565-0871 Japan
| | - Guillem Pratx
- Department of Radiation Oncology and Medical Physics, Stanford University 300 Pasteur Dr. Stanford CA 94305 USA
| | - Mamoru Fujitsuka
- SANKEN, Osaka University Mihogaoka 8-1, Ibaraki Osaka 567-0047 Japan
- Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University 2-1 Yamadaoka, Suita Osaka 565-0871 Japan
| | - Yasuko Osakada
- SANKEN, Osaka University Mihogaoka 8-1, Ibaraki Osaka 567-0047 Japan
- Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University 2-1 Yamadaoka, Suita Osaka 565-0871 Japan
- Institute for Advanced Co-Creation Studies, Osaka University Yamadagaoka 1-1, Suita Osaka 565-0871 Japan
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19
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Trung NT, Nhien PQ, Kim Cuc TT, Wu CH, Buu Hue BT, Wu JI, Li YK, Lin HC. Controllable Aggregation-Induced Emission and Förster Resonance Energy Transfer Behaviors of Bistable [ c2] Daisy Chain Rotaxanes for White-Light Emission and Temperature-Sensing Applications. ACS APPLIED MATERIALS & INTERFACES 2023; 15:15353-15366. [PMID: 36926804 DOI: 10.1021/acsami.2c21671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Bistable [c2] daisy chain rotaxanes with respective extended and contracted forms of [c2]A and [c2]B containing a blue-emissive anthracene (AN) donor and orange-emissive indandione-carbazole (IC) acceptor were successfully synthesized via click reaction. Tunable-emission bistable [c2] daisy chain rotaxanes with fluorescence changes from blue to orange, including bright-white-light emissions, could be modulated by the aggregation-induced emission (AIE) characteristics and Förster resonance energy transfer (FRET) processes through altering water fractions and shuttling processes (i.e., acid/base controls). Accordingly, as a result of excellent fine-tuning AIE (at 60% water content of H2O/THF) and FRET (with a compatible energy transfer of EFRET = 33.2%) behaviors after the shuttling process (by adding base), the brightest white-light emission at CIE (0.31, 0.37) with a quantum yield of Φ = 15.64% was obtained in contracted [c2]B with good control of molecular shuttling to possess higher photoluminescence (PL) quantum yields and better energy transfer efficiencies (i.e., the manipulation of reduced PET and enhanced FRET processes) due to their intramolecular aggregations of blue AN donors and orange IC acceptors with a proper water content of 60% H2O. Furthermore, dynamic light-scattering (DLS) and time-resolved photoluminescence (TRPL) measurements, along with theoretical calculations, were utilized to investigate and confirm AIE and FRET phenomena of bistable [c2] daisy chain rotaxanes. Especially, both bistable [c2] daisy chain rotaxanes [c2]A and [c2]B and noninterlocked monomer M could be exploited for the applications of ratiometric fluorescence temperature sensing due to the temperature effects on the AIE and FRET features. Based on these desirable bistable [c2] daisy chain rotaxane structures, this work provides a potential strategy for the future applications of tunable multicolor emission and ratiometric fluorescence temperature-sensing materials.
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Affiliation(s)
- Nguyen Thanh Trung
- Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Pham Quoc Nhien
- Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
- Department of Chemistry, College of Natural Sciences, Can Tho University, Can Tho City, Viet Nam
| | - Tu Thi Kim Cuc
- Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Chia-Hua Wu
- Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Bui Thi Buu Hue
- Department of Chemistry, College of Natural Sciences, Can Tho University, Can Tho City, Viet Nam
| | - Judy I Wu
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
| | - Yaw-Kuen Li
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
- Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Hong-Cheu Lin
- Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
- Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
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20
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Sensitivity of the hidden TADF to the linking topology of di-tert-butyl-carbazolyl and benzonitrile moieties in the molecules of emitters or hosts intended for efficient blue OLEDs. J Photochem Photobiol A Chem 2023. [DOI: 10.1016/j.jphotochem.2023.114686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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21
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Wu H, Shi YZ, Wang K, Yu J, Zhang XH. Conformational isomeric thermally activated delayed fluorescence (TADF) emitters: mechanism, applications, and perspectives. Phys Chem Chem Phys 2023; 25:2729-2741. [PMID: 36633179 DOI: 10.1039/d2cp05119b] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Thermally activated delayed fluorescence (TADF) materials have received enormous attention and the mechanism behind them has been investigated in depth. It has been found that some donor-acceptor (D-A) type TADF emitters could obviously exhibit dual stable conformations in the ground states and their distributions significantly affect the physical properties and device performances. Therefore, professional analysis and a summary of the relationship between molecular structures and performances are very important. In this review, we first summarize the mechanism and properties of TADF emitters with conformational isomerism. We also classify their recent progress according to their different applications, and provide an outlook on their perspectives.
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Affiliation(s)
- Hao Wu
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, P. R. China.
| | - Yi-Zhong Shi
- School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, P. R. China.
| | - Kai Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, P. R. China. .,Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, Jiangsu, P. R. China
| | - Jia Yu
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, P. R. China. .,Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, 215123, Jiangsu, P. R. China
| | - Xiao-Hong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, P. R. China. .,Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, 215123, Jiangsu, P. R. China
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22
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Zheng Y, Zhang L, Huang Z, Li S, Zuo L, Liang Y, Liu C, Luo S, Shi G, Zhao Z, Sun F, Xu B. Bright Organic Mechanoluminescence and Remarkable Mechanofluorochromism from Circularly Polarized TADF Enantiomers with Aggregation-Induced Emission Properties. Chemistry 2023; 29:e202202594. [PMID: 36318097 DOI: 10.1002/chem.202202594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 10/28/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
Abstract
The development of circularly polarized thermally activated delayed fluorescence (CP-TADF) luminogens with stimuli-response characteristics remains challenging. Herein, a pair of organic enantiomers, S-CzTA and R-CzTA, with aggregation-induced emission properties, have been successfully developed by introducing chiral 1,2,3,4-tetrahydronaphthalene and carbazole to phthalimide. They present CP-TADF properties in toluene solutions, giving dissymmetric factors of 0.84×10-3 and -1.03×10-3 , respectively. In the crystalline state, both S-CzTA and R-CzTA can emit intense blue TADF and produce very bright sky-blue mechanoluminescence (ML) and remarkable mechanofluorochromism (MFC) under the stimuli of mechanical force. Single-crystal analysis and theoretical calculation results suggest that their ML activities are probably associated with their chiral and polar molecular structures and unique non-centrosymmetric molecular packing modes. Furthermore, the MFC properties of the enantiomers likely originate from the destruction of crystal structure, leading to the planarization of molecular conformation. This work may provide helpful guidance for developing new CP-TADF materials with force-stimuli-responsive properties.
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Affiliation(s)
- Yitao Zheng
- School of Chemistry, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou, 510006, P. R. China
| | - Letian Zhang
- School of Chemistry, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou, 510006, P. R. China
| | - Zihao Huang
- School of Chemistry, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou, 510006, P. R. China
| | - Shufeng Li
- School of Chemistry, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou, 510006, P. R. China
| | - Lingqi Zuo
- School of Chemistry, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou, 510006, P. R. China
| | - Yaohui Liang
- School of Chemistry, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou, 510006, P. R. China
| | - Cong Liu
- School of Chemistry, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou, 510006, P. R. China
| | - Suilian Luo
- School of Chemistry, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou, 510006, P. R. China
| | - Guang Shi
- School of Chemistry, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou, 510006, P. R. China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Fengqiang Sun
- School of Chemistry, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou, 510006, P. R. China
| | - Bingjia Xu
- School of Chemistry, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou, 510006, P. R. China
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23
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Curtis K, Adeyiga O, Suleiman O, Odoh SO. Building on the strengths of a double-hybrid density functional for excitation energies and inverted singlet-triplet energy gaps. J Chem Phys 2023; 158:024116. [PMID: 36641391 DOI: 10.1063/5.0133727] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
It is demonstrated that a double hybrid density functional approximation, ωB88PTPSS, that incorporates equipartition of density functional theory and the non-local correlation, however with a meta-generalized gradient approximation correlation functional, as well as with the range-separated exchange of ωB2PLYP, provides accurate excitation energies for conventional systems, as well as correct prescription of negative singlet-triplet gaps for non-conventional systems with inverted gaps, without any necessity for parametric scaling of the same-spin and opposite-spin non-local correlation energies. Examined over "safe" excitations of the QUESTDB set, ωB88PTPSS performs quite well for open-shell systems, correctly and fairly accurately [relative to equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) reference] predicts negative gaps for 50 systems with inverted singlet-triplet gaps, and is one of the leading performers for intramolecular charge-transfer excitations and achieves near-second-order approximate coupled cluster (CC2) and second-order algebraic diagrammatic construction quality for the Q1 and Q2 subsets. Subsequently, we tested ωB88PTPSS on two sets of real-life examples from recent computational chemistry literature-the low energy bands of chlorophyll a (Chl a) and a set of thermally activated delayed fluorescence (TADF) systems. For Chl a, ωB88PTPSS qualitatively and quantitatively achieves DLPNO-STEOM-CCSD-level performance and provides excellent agreement with experiment. For TADF systems, ωB88PTPSS agrees quite well with spin-component-scaled CC2 (SCS-CC2) excitation energies, as well as experimental values, for the gaps between the S1 and T1 excited states.
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Affiliation(s)
- Kevin Curtis
- Department of Chemistry, University of Nevada, Reno, Nevada 89557, USA
| | - Olajumoke Adeyiga
- Department of Chemistry, University of Nevada, Reno, Nevada 89557, USA
| | - Olabisi Suleiman
- Department of Chemistry, University of Nevada, Reno, Nevada 89557, USA
| | - Samuel O Odoh
- Department of Chemistry, University of Nevada, Reno, Nevada 89557, USA
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24
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Yiu TC, Gnanasekaran P, Chen WL, Lin WH, Lin MJ, Wang DY, Lu CW, Chang CH, Chang YJ. Multifaceted Sulfone-Carbazole-Based D-A-D Materials: A Blue Fluorescent Emitter as a Host for Phosphorescent OLEDs and Triplet-Triplet Annihilation Up-Conversion Electroluminescence. ACS APPLIED MATERIALS & INTERFACES 2023; 15:1748-1761. [PMID: 36576167 DOI: 10.1021/acsami.2c21294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Electroluminescence (EL) from the singlet-excited (S1) state is the ideal choice for stable, high-performing deep-blue organic light-emitting diodes (OLEDs) owing to the advantages of an adequately short radiative lifetime, improved device durability, and low cost, which are the most important criteria for their commercialization. Herein, we present the design and synthesis of three donor-acceptor-donor (D-A-D)-configured deep-blue fluorescent materials (denoted as TC-1, TC-2, and TC-3) composed of a thioxanthone or diphenyl sulfonyl acceptor and phenyl carbazolyl donor. These systems exhibit strong deep-blue photoluminescence (422-432 nm) in solutions and redshifted emission (472-486 nm) in thin films. The solid-state photoluminescence quantum yield (PLQY) was estimated to be 78 and 94% for TC-2 and TC-3, respectively. TC-2 and TC-3 possess good molecular packing and large molecular cross-sectional areas, which not only improves the PLQY but enhances the triplet-triplet annihilation up-conversion (TTAUC) efficiency of fluorescent emitters. Furthermore, both compounds were applied as an acceptor for confirming their TTAUC property using bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetonate)iridium(III) (Ir(MDQ)2acac) as the sensitizer. Non-doped OLEDs based on TC-2 and TC-3 exhibit blue EL in the 461-476 nm range. In particular, TC-3 exhibits a maximum external quantum efficiency (EQEmax) of 5.1%, and its EL maximum is 476 nm. In addition, the three emitters were employed as hosts in red OLEDs using bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (Ir(piq)2acac) as the phosphorescent dopant. The red phosphorescent OLEDs based on TC-1, TC-2, and TC-3 achieve excellent EQEmax values of 21.6, 22.9, and 21.9%, respectively, and peak luminance efficiencies of 12.0, 14.0, and 12.3 cd A-1. These results highlight these fluorophores' versatility and promising prospects in practical OLED applications.
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Affiliation(s)
- Tsz Chung Yiu
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan
| | | | - Wei-Ling Chen
- Department of Electrical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Wei-Han Lin
- Department of Electrical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Ming-Jun Lin
- Department of Electrical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Di-Yan Wang
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan
| | - Chin-Wei Lu
- Department of Applied Chemistry, Providence University, Taichung 43301, Taiwan
| | - Chih-Hao Chang
- Department of Electrical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Yuan Jay Chang
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan
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25
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Dulov DA, Bogdanov AV, Dorofeev SG, Magdesieva TV. N, N'-Diaryldihydrophenazines as a Sustainable and Cost-Effective Alternative to Precious Metal Complexes in the Photoredox-Catalyzed Alkylation of Aryl Alkyl Ketones. Molecules 2022; 28:molecules28010221. [PMID: 36615415 PMCID: PMC9822323 DOI: 10.3390/molecules28010221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
An inexpensive and highly efficient metal-free alternative to commonly used Ru- and Ir-based catalysts was proposed. It was shown that the new 2,7-di-tert-butyl-5,10-bis(4-trifluoromethylphenyl)-5,10-dihydrophenazine outcompeted the iridium phenylpyridyl complex in photoredox activity in the alkylation of silyl enol ethers yielding aryl alkyl ketones. The reaction occurred under visible light irradiation at room temperature and was also applicable to drug derivatives (ibuprofen and naproxen). In-depth photophysical, electrochemical, and quantum chemical studies showed that the aforementioned N,N-diaryldihydrophenazine exhibited enhanced properties that were essential for the photoredox catalysis (a long-lived triplet excited state, strong reducing ability, high stability of the radical cations formed in single-electron-transfer event, and chemical inertness of the catalyst with respect to reactants). Importantly, the substituted N,N'-diaryldihydrophenazines could be obtained directly from diaryl amines; a facile, easily handled and scaled-up one-pot synthetic procedure was elaborated.
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26
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New Light-Green Thermally Activated Delayed Fluorescence Polymer Based on Dimethylacridine-Triphenyltriazine Light-Emitting Unit and Tetraphenylsilane Moiety as Non-Conjugated Backbone. Polymers (Basel) 2022; 15:polym15010067. [PMID: 36616417 PMCID: PMC9824120 DOI: 10.3390/polym15010067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/13/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022] Open
Abstract
In the search for solution-processable TADF materials as a light emitting layer for OLED devices, polymers have attracted considerable attention due to their better thermal and morphological properties in the film state with respect to small molecules. In this work, a new polymer (p-TPS-DMAC-TRZ) with thermally activated delayed fluorescence (TADF) light-emitting characteristics was prepared from a conjugation-break unit (TPS) and a well-known TADF core (DAMC-TRZ). This material was designed to preserve the photophysical properties of DAMC-TRZ, while improving other properties, such as thermal stability, promoted by its polymerization with a TPS core. Along with excellent solubility in common organic solvents such as toluene, chloroform and THF, the polymer (Mn = 9500; Mw = 15200) showed high thermal stability (TDT5% = 481 °C), and a Tg value of 265 °C, parameters higher than the reference small molecule DMAC-TRZ (TDT5% = 305 °C; Tg = 91 °C). The photoluminescence maximum of the polymer was centered at 508 nm in the solid state, showing a low redshift compared to DMAC-TRZ (500 nm), while also showing a redshift in solution with solvents of increasing polarity. Time-resolved photoluminescence of p-TPS-DMAC-TRZ at 298 K, showed considerable delayed emission in solid state, with two relatively long lifetimes, 0.290 s (0.14) and 2.06 s (0.50), and a short lifetime of 23.6 ns, while at 77 K, the delayed emission was considerably quenched, and two lifetimes in total were observed, 24.6 ns (0.80) and 180 ns (0.20), which was expected from the slower RISC process at lower temperatures, decreasing the efficiency of the delayed emission and demonstrating that p-TPS-DMAC-TRZ has a TADF emission. This is in agreement with room temperature TRPL measurements in solution, where a decrease in both lifetime and delayed contribution to total photoluminescence was observed when oxygen was present. The PLQY of the mCP blend films with 1% p-TPS-DMAC-DMAC-TRZ as a dopant was determined to be equal to 0.62, while in the pure film, it was equal to 0.29, which is lower than that observed for DMAC-TRZ (0.81). Cyclic voltammetry experiments showed similarities between p-TPS-DMAC-TRZ and DAMC-TRZ with HOMO and LUMO energies of -5.14 eV and -2.76 eV, respectively, establishing an electrochemical bandgap value of 2.38 eV. The thin film morphology of p-TPS-DMAC-TRZ and DMAC-TRZ was compared by AFM and FE-SEM, and the results showed that p-TPS-DMAC-TRZ has a smoother surface with fewer defects, such as aggregations. These results show that the design strategy succeeded in improving the thermal and morphological properties in the polymeric material compared to the reference small molecule, while the photophysical properties were mostly maintained, except for the PLQY determined in the pure films. Still, these results show that p-TPS-DMAC-TRZ is a good candidate for use as a light-emitting layer in OLED devices, especially when used as a host-guest mixture in suitable materials such as mCP.
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27
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Constructing high-efficiency orange-red thermally activated delayed fluorescence emitters by three-dimension molecular engineering. Nat Commun 2022; 13:7828. [PMID: 36535962 PMCID: PMC9763412 DOI: 10.1038/s41467-022-35591-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022] Open
Abstract
Preparing high-efficiency solution-processable orange-red thermally activated delayed fluorescence (TADF) emitters remains challenging. Herein, we design a series of emitters consisting of trinaphtho[3,3,3]propellane (TNP) core derivatized with different TADF units. Benefiting from the unique hexagonal stacking architecture of TNPs, TADF units are thus kept in the cavities between two TNPs, which decrease concentration quenching and annihilation of long-lived triplet excitons. According to the molecular engineering of TADF and host units, the excited states can further be regulated to effectively enhance spin-orbit coupling (SOC) processes. We observe a high-efficiency orange-red emission at 604 nm in one instance with high SOC value of 0.862 cm-1 and high photoluminescence quantum yield of 70.9%. Solution-processable organic light-emitting diodes exhibit a maximum external quantum efficiency of 24.74%. This study provides a universal strategy for designing high-performance TADF emitters through molecular packing and excited state regulation.
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28
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Huang Z, Lei B, Yang D, Ma D, Bin Z, You J. Modified Intramolecular‐Lock Strategy Enables Efficient Thermally Activated Delayed Fluorescence Emitters for Non‐Doped OLEDs. Angew Chem Int Ed Engl 2022; 61:e202213157. [DOI: 10.1002/anie.202213157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Indexed: 11/17/2022]
Affiliation(s)
- Zhenmei Huang
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. of China
| | - Bowen Lei
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. of China
| | - Dezhi Yang
- Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 P. R. China
| | - Dongge Ma
- Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 P. R. China
| | - Zhengyang Bin
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. of China
| | - Jingsong You
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. of China
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29
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Zhang K, Wang X, Zhang Q, Wu Z, Li X, Mu Q, Fan J, Wang CK, Lin L. Insights on isomeric emitters with thermally activated delayed fluorescence: Comparison between solvent and crystal state. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 278:121328. [PMID: 35537262 DOI: 10.1016/j.saa.2022.121328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 04/03/2022] [Accepted: 04/26/2022] [Indexed: 06/14/2023]
Abstract
Thermally activated delayed fluorescence (TADF) molecules with aggregation-induced emission (AIE) properties have attracted great attention in recent studies. In this study, three isomeric emitters DPAC-4PYPM, DPAC-TRZ and DPAC-6PYPM with TADF are studied in toluene and crystal with the combination of polarizable continuum model (PCM) and quantum mechanics and molecular mechanics (QM/MM) method. Results show that tiny difference of intramolecular interaction is induced due to the variation in the acceptor group, thus similar geometries and stacking patterns in crystal are obtained for three molecules. Our calculation also indicates that the energy diagram is quite different for three molecules in both toluene and crystal state, while the participation of higher triplet excited states provide additional decay channels for the reverse intersystem crossing (RISC) process, which favors the generation of TADF. In addition, the bending vibrations of the phenyl in the donor and the stretching vibrations of the C=C and C-H bonds are suppressed due to the intermolecular interactions in crystal state, thus block the excited-state energy consumption pathway. It indicates that all three molecules are typical AIE systems. Our calculation results agree with experimental measurements and provide more useful information for TADF emitters with AIE properties.
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Affiliation(s)
- Kai Zhang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Xiaofei Wang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Qun Zhang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Zhimin Wu
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Xiaofang Li
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Qingfang Mu
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Jianzhong Fan
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Chuan-Kui Wang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China.
| | - Lili Lin
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China.
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30
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Shishlikova MA, Chunikhin SS, Ershov OV. Synthesis and Optical Properties of Di- and Trifluoromethyl-Substituted Pyridine Derivatives Containing a Tricyanobutadiene Moiety. RUSS J GEN CHEM+ 2022. [DOI: 10.1134/s1070363222090122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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31
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Liu Y, Yang J, Mao Z, Chen X, Yang Z, Ge X, Peng X, Zhao J, Su SJ, Chi Z. Asymmetric Thermally Activated Delayed Fluorescence Emitter for Highly Efficient Red/Near-Infrared Organic Light-Emitting Diodes. ACS APPLIED MATERIALS & INTERFACES 2022; 14:33606-33613. [PMID: 35819262 DOI: 10.1021/acsami.2c07617] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Developing highly efficient red/near-infrared thermally activated delayed fluorescence (TADF) materials is of great importance for organic light-emitting diodes (OLEDs). Here, we reported an asymmetric TADF emitter (TCPQ), which exhibits a high reverse intersystem crossing rate as well as a low non-radiative rate due to molecular symmetry breaking through multiple donor substitution. The coexistence of multiple donors endows TCPQ with not only near-infrared emission but also excellent device performances. As for the TCPQ-based OLEDs, the 10 and 20 wt % doped devices exhibit outstanding external quantum efficiencies (EQEs) of 21.9 and 19.2% with red emission peaks at 612 and 642 nm, respectively. Meanwhile, the non-doped device achieves an EQE of 5.4% with an emission peak at 718 nm, showing near-infrared emission. These device efficiencies are among the best performances of red/near-infrared TADF-OLEDs, demonstrating that the asymmetry design is a potential strategy for constructing long wavelength TADF materials with high efficiency.
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Affiliation(s)
- Yanyan Liu
- PCFM Lab, GD HPPC Lab, Guangdong Engineering Technology Research Centre for High-performance Organic and Polymer Photoelectric Functional Films, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
| | - Jiaji Yang
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Zhu Mao
- Shenzhen Institute of Advanced Electronic Materials, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Xiaojie Chen
- PCFM Lab, GD HPPC Lab, Guangdong Engineering Technology Research Centre for High-performance Organic and Polymer Photoelectric Functional Films, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
| | - Zhan Yang
- PCFM Lab, GD HPPC Lab, Guangdong Engineering Technology Research Centre for High-performance Organic and Polymer Photoelectric Functional Films, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
| | - Xiangyu Ge
- PCFM Lab, GD HPPC Lab, Guangdong Engineering Technology Research Centre for High-performance Organic and Polymer Photoelectric Functional Films, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
| | - Xiaomei Peng
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Juan Zhao
- State Key Laboratory of OEMT, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Shi-Jian Su
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Zhenguo Chi
- PCFM Lab, GD HPPC Lab, Guangdong Engineering Technology Research Centre for High-performance Organic and Polymer Photoelectric Functional Films, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of OEMT, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
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32
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Bartkowski K, Zimmermann Crocomo P, Kochman MA, Kumar D, Kubas A, Data P, Lindner M. Tandem rigidification and π-extension as a key tool for the development of a narrow linewidth yellow hyperfluorescent OLED system. Chem Sci 2022; 13:10119-10128. [PMID: 36128243 PMCID: PMC9430727 DOI: 10.1039/d2sc03342a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/20/2022] [Indexed: 11/21/2022] Open
Abstract
Hyperfluorescence (HF), a relatively new phenomenon utilizing the transfer of excitons between two luminophores, requires careful pairwise tuning of molecular energy levels and is proposed to be the crucial step towards the development of new, highly effective OLED systems. To date, barely few HF yellow emitters with desired narrowband emission but moderate external quantum efficiency (EQE < 20%) have been reported. This is because a systematic strategy embracing both Förster resonance energy transfer (FRET) and triplet to singlet (TTS) transition as complementary mechanisms for effective exciton transfer has not yet been proposed. Herein, we present a rational approach, which allows, through subtle structural modification, a pair of compounds built from the same donor and acceptor subunits, but with varied communication between these ambipolar fragments, to be obtained. The TADF-active dopant is based on a naphthalimide scaffold linked to the nitrogen of a carbazole moiety, which through the introduction of an additional bond leads not only to π-cloud enlargement, but also rigidifies and inhibits the rotation of the donor. This structural change prevents TADF, and guides bandgaps and excited state energies to simultaneously pursue FRET and TTS processes. New OLED devices utilizing the presented emitters show excellent external quantum efficiency (up to 27%) and a narrow full width at half maximum (40 nm), which is a consequence of very good alignment of energy levels. The presented design principles prove that only a minor structural modification is needed to obtain commercially applicable dyes for HF OLED devices. The rigidification with simultaneous π-extension of TADF-active dye leads to fluorescent dopant with fine-tuned energy levels. These used as hyperfluorescent OLED device shows extraordinary EQE and brightness due to effective FRET and TTS processes.![]()
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Affiliation(s)
- Krzysztof Bartkowski
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 Warsaw 01-224 Poland
| | | | - Michał Andrzej Kochman
- Institute of Physical Chemistry, Polish Academy of Sciences Kasprzaka 44/52 Warsaw 01-224 Poland
| | - Dharmandra Kumar
- Faculty of Chemistry, Silesian University of Technology M. Strzody 9 Gliwice 44-100 Poland
| | - Adam Kubas
- Institute of Physical Chemistry, Polish Academy of Sciences Kasprzaka 44/52 Warsaw 01-224 Poland
| | - Przemysław Data
- Faculty of Chemistry, Silesian University of Technology M. Strzody 9 Gliwice 44-100 Poland
| | - Marcin Lindner
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 Warsaw 01-224 Poland
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