1
|
Xie DD, Liao HS, Wang BY, Chen D, Chi HJ, Lv YL, Dong Y, Li X. New Phenanthro[9,10-d]oxazole-Based Fluorophores with Hybridized Local and Charge-Transfer Characteristics for Highly Efficient Blue Non-Doped OLEDs with Negligible Efficiency Roll-Off. Chemistry 2024; 30:e202400121. [PMID: 38538538 DOI: 10.1002/chem.202400121] [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: 01/11/2024] [Indexed: 04/25/2024]
Abstract
It is vital to develop highly efficient non-doped blue organic light-emitting diodes (OLEDs) with high color purity and low-efficiency roll-off for applications in display and lighting. Herein, two blue D-A fluorophores TPA-PO and TPA-DPO are designed and synthesized, in which phenanthro[9,10-d]oxazole (PO) acts as the acceptor and triphenylamine as the donor. TPA-PO and TPA-DPO display good thermal stability and efficient luminescence efficiency in neat film. Results based on photophysical property and theoretical calculation demonstrate that TPA-PO and TPA-DPO possess the hybridized local and charge-transfer (HLCT) feature, which can utilize the triplet exciton to achieve highly efficient electroluminance (EL). The non-doped OLEDs with TPA-PO/TPA-DPO as pure emissive layer show the uniform EL emission peak at 468 nm, corresponding to CIE coordinates of (0.168, 0.187) and (0.167, 0.167), respectively. The TPA-DPO-based non-doped OLEDs provide the maximum external quantum efficiency (EQE) of 7.99 % and high exciton utility efficiency of 48.4 %~72.6 %. Moreover, the TPA-DPO-based device exhibits low-efficiency roll-off, still maintaining the EQE of 6.03 % at the high luminance of 5000 cd m-2. Those findings state clearly that PO is a promising building block of blue fluorophore with a potential HLCT feature to be applied in non-doped OLEDs.
Collapse
Affiliation(s)
- Dong-Dong Xie
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address
| | - Hao-Sen Liao
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address
| | - Bao-Yue Wang
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address
| | - Dong Chen
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address
| | - Hai-Jun Chi
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address
| | - Yan-Li Lv
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address
| | - Yan Dong
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address
| | - Xiao Li
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China E-mail: address
| |
Collapse
|
2
|
Jayabharathi J, Thanikachalam V. Robust luminogens as cutting-edge tools for efficient light emission in recent decades. Phys Chem Chem Phys 2024; 26:13561-13605. [PMID: 38655772 DOI: 10.1039/d4cp00737a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Blue luminogens play a vital role in white lighting and potential metal-free fluorescent materials and their high-lying excited states contribute to harvesting triplet excitons in devices. However, in TADF-OLEDs (ΔEST < 0.1 eV), although T1 excitons transfer to S1via RISC with 100% IQE, the longer lifetime of blue TADF suffers from efficiency roll-off (RO). In this case, hybridized local and charge transfer (HLCT) materials have attracted significant interest in lighting owing to their 100% hot exciton harvesting and enhanced efficiency. Both academics and industrialists widely use the HLCT strategy to improve the efficiency of fluorescent organic light-emitting diodes (FOLEDs) by harvesting dark triplet excitons through the RISC process. Aggregation-induced emissive materials (AIEgens) possess tight packing in the aggregation state, and twisted AIEgens with HLCT behaviour have a shortened conjugation length, inducing blue emission and making them suitable candidates for OLED applications. TTA-OLEDs are used in commercial BOLEDs because of their moderate efficiency and reasonable operation lifetime. In this review, we discuss the devices based on TTA fluorophores, TADF fluorophores, HLCT fluorophores, AIEgens and HLCT-sensitized fluorophores (HLCT-SF), which break through the statistical limitations.
Collapse
Affiliation(s)
- Jayaraman Jayabharathi
- Department of Chemistry, Annamalai University, Annamalainagar, Tamilnadu-608 002, India.
| | | |
Collapse
|
3
|
Kumar K, Thakur D. Overview of imidazole-based fluorescent materials with hybridized local and charge transfer and hot-exciton pathway characteristics in excited states. SOFT MATTER 2024; 20:1669-1688. [PMID: 38315555 DOI: 10.1039/d3sm01005h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Herein, we discuss an imidazole-based molecular framework, which can successfully transform triplet excitons present in high triplet levels into singlet states. We explain the working mechanisms of different methods for collecting triplet excitons, including hot excitons or HLCT states. After the development of an hot exciton material by Ma and Yang, many studies have demonstrated that the organic conjugated molecules having imidazole core have possibilities to show high efficiencies via hot exciton pathways. Finally, we provide a detailed investigation of recently published hot exciton luminogens based on imidazole molecular frameworks. This review provides an overview of the molecular structures, frontier molecular orbital information, and glass transition temperature of developed luminogens as well as the efficiency of organic light-emitting diodes (OLED) devices.
Collapse
Affiliation(s)
- Krishan Kumar
- School of Chemical Sciences, IIT Mandi, Himachal Pradesh 175005, India.
| | - Diksha Thakur
- School of Chemical Sciences, IIT Mandi, Himachal Pradesh 175005, India.
| |
Collapse
|
4
|
Han P, Lin C, Xia E, Cheng J, Xia Q, Yang D, Qin A, Ma D, Tang BZ. Non-Doped Blue AIEgen-Based OLED with EQE Approaching 10.3 . Angew Chem Int Ed Engl 2023; 62:e202310388. [PMID: 37668100 DOI: 10.1002/anie.202310388] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/22/2023] [Accepted: 09/04/2023] [Indexed: 09/06/2023]
Abstract
Aggregation-induced emission (AIE) luminogens (AIEgens) are attractive for the construction of non-doped blue organic light-emitting diodes (OLEDs) owning to their high emission efficiency in the film state. However, the large internal inversion rate (kIC (Tn) ) between high-lying triplet levels (Tn ) and Tn-1 causes a huge loss of triplet excitons, resulting in dissatisfied device performance of these AIEgens-based non-doped OLEDs. Herein, we designed and synthesized a blue luminogen of DPDPB-AC by fusing an AIEgen of TPB-AC and a DMPPP, which feature hot exciton and triplet-triplet annihilation (TTA) up-conversion process, respectively. DPDPB-AC successfully inherits the AIE feature and excellent horizontal dipole orientation of TPB-AC. Furthermore, it owes smaller kIC (Tn) than TPB-AC. When DPDPB-AC was applied in OLED as non-doped emitting layer, an outstanding external quantum efficiency of 10.3 % and an exceptional brightness of 69311 cd m-2 were achieved. The transient electroluminescent measurements and steady-state dynamic analysis confirm that both TTA and hot exciton processes contribute to such excellent device performance. This work provides a new insight into the design of efficient organic fluorophores by managing high-lying triplet excitons.
Collapse
Affiliation(s)
- Pengbo Han
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Chengwei Lin
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Erhan Xia
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Jiawei Cheng
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Qing Xia
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Dezhi Yang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Anjun Qin
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Dongge Ma
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Ben Zhong Tang
- Center for Aggregation-Induced Emission, AIE Institute, South China University of Technology, Guangzhou, 510640, China
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Guangdong, 518172, China
- Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and Reconstruction, The Hong Kong University of Science & Technology, Kowloon, 999077, Hong Kong, China
| |
Collapse
|
5
|
Abdollahi MF, Zhao Y. Donor-Acceptor Fluorophores and Macrocycles Built Upon Wedge-Shaped π-Extended Phenanthroimidazoles. J Org Chem 2023; 88:3451-3465. [PMID: 36862080 DOI: 10.1021/acs.joc.2c02511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
A class of wedge-shaped organic π-fluorophores featuring a 6,9-diphenyl-substituted phenanthroimidazole (PI) core was designed, synthesized, and characterized. Among them, a π-extended PI derivative containing two electron-withdrawing aldehyde groups was found to exhibit versatile solid-state packing properties as well as strong solvatofluorochromism in different organic solvents. Another PI derivative that was functionalized with two electron-donating 1,4-dithiafulvenyl (DTF) end groups showed versatile redox reactivities and quenched fluorescence. Treatment of this wedge-shaped bis(DTF)-PI compound with iodine resulted in oxidative coupling reactions, leading to the formation of intriguing macrocyclic products that carry redox-active tetrathiafulvalene vinylogue (TTFV) moieties in their structures. Mixing the bis(DTF)-PI derivative with fullerene (C60 or C70) in an organic solvent resulted in substantial fluorescence enhancement (turn-on). In this process, fullerene acted as a photosensitizer to generate singlet oxygen, which in turn induced oxidative C = C bond cleavages and converted nonfluorescent bis(DTF)-PI into highly fluorescent dialdehyde-substituted PI. Treatment of TTFV-PI macrocycles with a small amount of fullerene also led to a moderate degree of fluorescence enhancement, but this is not because of photosensitized oxidative cleavage reactions. Instead, competitive photoinduced electron transfer from TTFV to fullerene can be attributed to their fluorescence turn-on behavior.
Collapse
Affiliation(s)
- Maryam F Abdollahi
- Department of Chemistry, Memorial University, Core Science Facility, 45 Arctic Avenue, St. John's, NL A1C 5S7, Canada
| | - Yuming Zhao
- Department of Chemistry, Memorial University, Core Science Facility, 45 Arctic Avenue, St. John's, NL A1C 5S7, Canada
| |
Collapse
|
6
|
Lian M, Ye Z, Mu Y, Hu D, Liu Y, Zhang H, Ji S, Huo Y. Progress on Blue-Emitting Hot Exciton Materials. CHINESE J ORG CHEM 2023. [DOI: 10.6023/cjoc202207042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
|
7
|
Sharma SJ, Sekar N. Charge Transfer as Bridging Correlator for DSSC Efficiency and NLO Property. ChemistrySelect 2022. [DOI: 10.1002/slct.202203262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Suryapratap J. Sharma
- Dyestuff Technology Department (Currently named Department of Specialty Chemicals Technology) Institute of Chemical Technology Nathalal Parekh Marg, Matunga Mumbai 400019 Maharashtra India
| | - Nagaiyan Sekar
- Dyestuff Technology Department (Currently named Department of Specialty Chemicals Technology) Institute of Chemical Technology Nathalal Parekh Marg, Matunga Mumbai 400019 Maharashtra India
| |
Collapse
|
8
|
Han P, Xia E, Qin A, Tang BZ. Adjustable and smart AIEgens for nondoped blue and deep blue organic light-emitting diodes. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
9
|
Zhang H, Zhou M, Wang H, Zhao Y, Yu T. Synthesis and properties of butterfly-shaped naphthalimide-based AIE-active fluorescent dyes. CHEMICAL PAPERS 2022. [DOI: 10.1007/s11696-021-02058-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
10
|
Phenanthroimidazole substituted imidazo[1,2-a]pyridine derivatives for deep-blue electroluminescence with CIEy ∼ 0.08. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2021.113600] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
11
|
Zheng XH, Huang TT, Yang GX, Lin AQ, Chen K, Chen X, Li JY, Tong QX. Constructing Highly Efficient Blue OLEDs with External Quantum Efficiencies up to 7.5 % Based on Anthracene Derivatives. Chemistry 2021; 27:16181-16188. [PMID: 34554619 DOI: 10.1002/chem.202103012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Indexed: 11/08/2022]
Abstract
Acquiring desirable device performance with deep-blue color purity that fulfills practical application requirements is still a challenge. Bipolar fluorescent emitters with hybrid local and charge transfer (HLCT) state may serve to address this issue. Herein, by inserting anthracene core in the deep-blue building blocks, the authors successfully developed two highly twisted D-π-A fluorescent emitters, ICz-An-PPI and IP-An-PPI, featuring different acceptor groups. Both exhibited superb thermal stabilities, high photo luminescent quantum yields and excellent bipolar transport capabilities. The non-doped OLEDs using ICz-An-PPI and IP-An-PPI as the emitting layers showed efficient blue emission with an external quantum efficiency (EQEmax ) of 4.32 % and 5.41 %, and the CIE coordinates of (0.147, 0.180) and (0.149, 0.150), respectively. In addition, the deep blue doped device based on ICz-An-PPI was achieved with an excellent CEmax of 5.83 cd A-1 , EQEmax of 4.6 % and the CIE coordinate of (0.148, 0.078), which is extremely close to the National Television Standards Committee (NTSC) standard. Particularly, IP-An-PPI-based doped device had better performance, with an EQEmax of 7.51 % and the CIE coordinate of (0.150, 0.118), which was very impressive among the recently reported deep-blue OLEDs with the CIEy <0.12. Such high performance may be attributed to the hot exciton HLCT mechanism via T7 to S2 . Our work may provide a new approach for designing high-efficiency deep-blue materials.
Collapse
Affiliation(s)
- Xu-Hui Zheng
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered, Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China.,Department of Chemistry, Guangdong Technion Israel Institute of Technology, Shantou, 515063, China
| | - Ting-Ting Huang
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian, 116024, China
| | - Guo-Xi Yang
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered, Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| | - An-Qi Lin
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered, Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| | - Keng Chen
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered, Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| | - Xiang Chen
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered, Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| | - Jiu-Yan Li
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian, 116024, China
| | - Qing-Xiao Tong
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered, Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| |
Collapse
|
12
|
Xu Y, Xu P, Hu D, Ma Y. Recent progress in hot exciton materials for organic light-emitting diodes. Chem Soc Rev 2020; 50:1030-1069. [PMID: 33231588 DOI: 10.1039/d0cs00391c] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
According to Kasha's rule, high-lying excited states usually have little effect on fluorescence. However, in some molecular systems, the high-lying excited states partly or even mainly contribute to the photophysical properties, especially in the process of harvesting triplet excitons in organic electroluminescent devices. In the current review, we focus on a type of organic light-emitting diode (OLED) materials called "hot exciton" materials, which can effectively harness the non-radiative triplet excitons via reverse intersystem crossing (RISC) from high-lying triplet states to singlet states (Tn→ Sm; n≥ 2, m≥ 1). Since Ma and Yang proposed the hot exciton mechanism for OLED material design in 2012, there have been many reports aiming at the design and synthesis of novel hot exciton luminogens. Herein, we present a comprehensive review of the recent progress in hot exciton materials. The developments of the hot exciton mechanism are reviewed, the fundamental principles regarding molecular design are discussed, and representative reported hot exciton luminogens are summarized and analyzed, along with their structure-property relationships and OLED applications.
Collapse
Affiliation(s)
- Yuwei Xu
- 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.
| | | | | | | |
Collapse
|
13
|
Zheng XH, Zhao JW, Chen X, Cai R, Yang GX, Zhu JJ, Tang SS, Lin ZH, Tao SL, Tong QX. Imidazo[1,2-a]pyridine as an Electron Acceptor to Construct High-Performance Deep-Blue Organic Light-Emitting Diodes with Negligible Efficiency Roll-Off. Chemistry 2020; 26:8588-8596. [PMID: 32187750 DOI: 10.1002/chem.202000518] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/17/2020] [Indexed: 01/09/2023]
Abstract
Two novel bipolar deep-blue fluorescent emitters, IP-PPI and IP-DPPI, featuring different lengths of the phenyl bridge, were designed and synthesized, in which imidazo[1,2-a]pyridine (IP) and phenanthroimidazole (PI) were proposed as an electron acceptor and an electron donor, respectively. Both of them exhibit outstanding thermal stability and high emission quantum yields. All the devices based on these two materials showed negligible efficiency roll-off with increasing current density. Impressively, non-doped organic light-emitting diodes (OLEDs) based on IP-PPI and IP-DPPI exhibited external quantum efficiencies (EQEs) of 4.85 % and 4.74 % with CIE coordinates of (0.153, 0.097) and (0.154, 0.114) at 10000 cd m-2 , respectively. In addition, the 40 wt % IP-PPI doped device maintained a high EQE of 5.23 % with CIE coordinates of (0.154, 0.077) at 10000 cd m-2 . The doped device based on 20 wt % IP-DPPI exhibited a higher deep-blue electroluminescence (EL) performance with a maximum EQE of up to 6.13 % at CIE of (0.153, 0.078) and maintained an EQE of 5.07 % at 10000 cd m-2 . To the best of our knowledge, these performances are among the state-of-the art devices with CIEy ≤0.08 at a high brightness of 10000 cd m-2 . Furthermore, by doping a red phosphorescent dye Ir(MDQ)2 (MDQ=2-methyldibenzo[f,h]quinoxaline) into the IP-PPI and IP-DPPI hosts, high-performance red phosphorescent OLEDs with EQEs of 20.8 % and 19.1 % were achieved, respectively. This work may provide a new approach for designing highly efficient deep-blue emitters with negligible roll-off for OLED applications.
Collapse
Affiliation(s)
- Xu-Hui Zheng
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| | - Jue-Wen Zhao
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054, P. R. China
| | - Xiang Chen
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| | - Ruoke Cai
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| | - Guo-Xi Yang
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| | - Jie-Ji Zhu
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| | - Shan-Shun Tang
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| | - Zhi-Hong Lin
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| | - Si-Lu Tao
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054, P. R. China
| | - Qing-Xiao Tong
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Material of Guangdong Province, Shantou University, Guangdong, 515063, P. R. China
| |
Collapse
|
14
|
Jayabharathi J, Anudeebhana J, Thanikachalam V, Sivaraj S. Efficient fluorescent OLEDS based on assistant acceptor modulated HLCT emissive state for enhancing singlet exciton utilization. RSC Adv 2020; 10:8866-8879. [PMID: 35496536 PMCID: PMC9049980 DOI: 10.1039/d0ra00658k] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 02/20/2020] [Indexed: 01/30/2023] Open
Abstract
Phenylamine phenanthroimidazole based bipolar compounds with donor-acceptor (D-A) architecture namely, 4-(1-(2,3-dihydrobenzo[b][1,4]dioxin-5-yl)-6,9-di(pyren-4-yl)-1H-phenanthro[9,10-d]imidazol-2-yl)-N,N-diphenylaniline (DDPPPA) and 4'-(1-(2,3-dihydrobenzo[b][1,4]dioxin-5-yl)-6,9-di(pyren-4-yl)-1H-phenanthro[9,10-d]imidazol-2-yl)-N,N-diphenyl-[1,1'-biphenyl]-4-amine (DDPBA) have been synthesized with highly fluorescent pyrene moieties at C6- and C9-positions. The C6 and C9 modification enhanced the thermal, photochemical and electroluminescent properties. Both molecules were employed as blue emitters in non doped organic light emitting devices (OLEDs) and show high performances due to hybridized local and charge-transfer properties. An OLED with DDPPPA/DDPBA emissive layer shows deep-blue emission with maximum external quantum efficiency (η ex), current efficiency (η c) and power efficiency (η p) of 5.7/6.0%, 10.5/12.0 cd A-1 and 8.3/9.2 lm W-1, respectively. Both devices show high singlet exciton utilizing efficiency (η s) of DDPPPA-31.33% and DDPBA-35.29%. The doped device m-MTDATA:DDPPPA/m-MTDATA:DDPBA shows maximum efficiencies of η c -7.4/8.23 cd A-1; η p -5.8/6.13 lm W-1; η ex -4.72/5.63% (5 wt%):η c -8.36/9.15 cd A-1; η p -6.32/6.65 lm W-1; η ex -4.86/5.45% (10 wt%):η c -9.58/10.02 cd A-1; η p -7.8/8.25 lm W-1; η ex -5.96/6.25% (20 wt%). The doped device based on TAPC host TAPC:DDPPPA/TAPC:DDPBA exhibits maximum efficiencies of η c -9.60/10.03 cd A-1; η p -7.81/8.26 lm W-1; η ex -5.96/6.25% (20 wt%).
Collapse
Affiliation(s)
- Jayaraman Jayabharathi
- Department of Chemistry, Material Science Lab, Annamalai University Annamalai Nagar Tamilnadu-608 002 India
| | | | - Venugopal Thanikachalam
- Department of Chemistry, Material Science Lab, Annamalai University Annamalai Nagar Tamilnadu-608 002 India
| | - Sekar Sivaraj
- Department of Chemistry, Material Science Lab, Annamalai University Annamalai Nagar Tamilnadu-608 002 India
| |
Collapse
|
15
|
Jayabharathi J, Goperundevi G, Thanikachalam V, Panimozhi S. Regulation of Singlet and Triplet Excitons in a Single Emission Layer: Efficient Fluorescent/Phosphorescent Hybrid White Organic Light-Emitting Diodes. ACS OMEGA 2019; 4:15030-15042. [PMID: 31552345 PMCID: PMC6751706 DOI: 10.1021/acsomega.9b01815] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 07/23/2019] [Indexed: 06/10/2023]
Abstract
Two efficient fluorescent molecules, viz., (E)-2-(2-4-(1-2,3-dihydrobenzo[b][1,4]dioxin-5-yl)-4,5-diphenyl-H-imidazole-2-yl)-[1,1-biphenyl]-4-yl)vinyl-1-yl(naphthalene-1-yl)-1H-phenanthro[9,10-d]imidazole (DDIBNPPI) and (E)-4-(2-(2-(-4'-1(2,3-dihyderobenzo[b][1,4]dioxin-5-yl)-4,5-diphenyl-1H-imidazole-2-yl)-[1,1'-biphenyl]-4-yl)vinyl)-1H-phenanthr[9,10-d]imidazole-1-yl)-1-napthronitrile (DDIBPPIN), were designed and synthesized. DDIBNPPI and DDIBPPIN were obtained by rupturing the covalent bond of phenanthrimidazole core to prevent aggregation-induced quenching. In DDIBPPIN, naphthonitrile group was incorporated into azomethine nitrogen of phenanthrimidazole to enhance charge-transfer ability. The DDIBPPIN/CBP:DDIBPPIN-based device shows blue emission with ηc (current efficiency) of 4.91/4.10 cd/A, ηp (power efficiency) of 4.56/3.84 lm/W, and ηex (external quantum efficiency) of 5.11/5.96%. The ηs (exciton utilization efficiency) values of DDIPNPPI and DDIBPPIN are of 27.0 and 30.3%, respectively. The DDIPNPPI and DDIBPPIN materials employed as a host to fabricate green and red phosphorescent organic light-emitting diodes. The red/white devices (with 0.4% dopant concentration) with DDIBPPIN:Ir(MDQ)2(acac) exhibit maximum L of 69889/26319 cd/m2, ηex of 19.6/16.6%, ηc of 34.6/35.6 cd/A, and ηp of 35.8/36.6 lm/W. The device with DDIBPPIN:Ir(ppy)3/DDIPNPPI:Ir(ppy)3 exhibits green emission [Commission Internationale de l'Eclairage (0.30,0.60)/(0.30,0.60)] with maximum L of 69906/69482 cd/m2, ηex of 17.9/17.0%, ηc of 59.8/58.6 cd/A, and ηp of 63.6/61.3 lm/W. The white device using DDIBPPI:Ir(ppy)3 (with 0.4% dopant concentration) exhibits maximum L of 22152 cd/m2, ηex of 15.8%, ηc of 31.4 cd/A, and ηp of 36.1 lm/W.
Collapse
|
16
|
Singh DK, Jang K, Kim J, Lee J, Kim I. Intramolecular Electrophilic Cyclization Approach to 6-Substituted Naphtho[2,1- b]benzofurans: Novel Dual-State Emissive Fluorophores with Blue Emission. ACS COMBINATORIAL SCIENCE 2019; 21:408-416. [PMID: 30925043 DOI: 10.1021/acscombsci.9b00006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A regiospecific synthesis of naphtho[2,1- b]benzofurans with a substituent at the C6 position was achieved via intramolecular 6-endo-dig electrophilic cyclization under acidic conditions to construct the central aromatic C ring. Screening of the synthesized compounds using a high-content imaging system enabled us to discover novel dual state emissive compounds 2{ 1,6}, 2{ 1,8}, and 2{ 4,3}, which are highly emissive with blue emission in their solid states as well as in solution states in most solvents. In addition, the compounds 2{ 4,3}, 2{ 4,12}, and 2{ 5,13} were found to be the most cell permeable in HeLa cells for live cell imaging with negligible phototoxicity.
Collapse
Affiliation(s)
- Dileep Kumar Singh
- College of Pharmacy and Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
| | - Kyungkuk Jang
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Jinhwang Kim
- College of Pharmacy and Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
| | - Jeeyeon Lee
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Ikyon Kim
- College of Pharmacy and Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
| |
Collapse
|
17
|
Kaur B, Moghe D, Kabra D, Jacob J. Design and synthesis of highly twisted phenanthroimidazole substituted blue-emitting truxene based fluorescent chromophores. NEW J CHEM 2019. [DOI: 10.1039/c8nj04293d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highly twisted truxene–phenanthroimidazole conjugates have been designed to obtain blue chromophores. The materials show good quantum yields of up to 0.83 and predominant radiative pathways.
Collapse
Affiliation(s)
- Banpreet Kaur
- Department of Materials Science and Engineering, Indian Institute of Technology Delhi
- Hauz Khas
- India
| | - Dhanashree Moghe
- Department of Physics, Indian Institute of Technology Bombay
- Powai
- India
| | - Dinesh Kabra
- Department of Physics, Indian Institute of Technology Bombay
- Powai
- India
| | - Josemon Jacob
- Department of Materials Science and Engineering, Indian Institute of Technology Delhi
- Hauz Khas
- India
| |
Collapse
|
18
|
Joseph V, Thomas KRJ, Sahoo S, Singh M, Dubey DK, Jou JH. Vinyl-Linked Cyanocarbazole-Based Emitters: Effect of Conjugation and Terminal Chromophores on the Photophysical and Electroluminescent Properties. ACS OMEGA 2018; 3:16477-16488. [PMID: 31458283 PMCID: PMC6644140 DOI: 10.1021/acsomega.8b02198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/20/2018] [Indexed: 06/10/2023]
Abstract
A series of carbazole-based dyes functionalized with different auxochromes via vinyl linker have been synthesized and characterized. A progressive shift in the absorption maximum is observed as the conjugation and electron-donating nature of chromophore increases. Dyes containing electron-releasing terminal groups such as triphenylamine and carbazole exhibited positive emission solvatochromism attributable to an induced intramolecular charge transfer from triphenylamine/carbazole donor to cyano acceptor. The superior electroluminescence performance of disubstituted dyes demonstrates the role of an additional cyanocarbazole in achieving balanced charge transport compared to monosubstituted analogues. In addition, the electroluminescence performance of the dyes exhibited trends attributable to the electron richness of the linker/terminal chromophore. Thus, the carbazole-based derivatives displayed better electroluminescence efficiency than the analogous fluorene derivatives. Similarly, 2,7-substituted carbazole derivative exhibited better performance than the 3,6-substituted carbazole derivative. A doped electroluminescent device containing 3 wt % tricarbazole derivative showed blue emission with a high external quantum efficiency of 5.3% at a practical brightness of 1000 cd/m2.
Collapse
Affiliation(s)
- Vellaichamy Joseph
- Organic
Materials Laboratory, Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India
| | - K. R. Justin Thomas
- Organic
Materials Laboratory, Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India
| | - Snehasis Sahoo
- Department
of Materials Science and Engineering, National
Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Meenu Singh
- Department
of Materials Science and Engineering, National
Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Deepak Kumar Dubey
- Department
of Materials Science and Engineering, National
Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Jwo-Huei Jou
- Department
of Materials Science and Engineering, National
Tsing-Hua University, Hsinchu 30013, Taiwan
| |
Collapse
|
19
|
Liu B, Zhu Z, Zhao J, He D, Wang Z, Luo C, Tong Q, Lee C, Tao S. Ternary Acceptor–Donor–Acceptor Asymmetrical Phenanthroimidazole Molecule for Highly Efficient Near‐Ultraviolet Electroluminescence with External Quantum Efficiency (EQE) >4 %. Chemistry 2018; 24:15566-15571. [DOI: 10.1002/chem.201801822] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/31/2018] [Indexed: 01/12/2023]
Affiliation(s)
- Bin Liu
- Department of Chemistry and Key Laboratory for, Preparation and Application of Ordered Structural Materials of, Guangdong Province Shantou University Guangdong 515063 P.R. China
- Department of Physics Fudan University Shanghai 200433 P.R. China
| | - Ze‐Lin Zhu
- Center of Super-Diamond and Advanced Films (COSDAF) and Department of Chemistry City University of Hong Kong Hong Kong SAR P.R. China
| | - Jue‐Wen Zhao
- School of Optoelectronic Information University of Electronic Science and Technology of China (UESTC) Chengdu 610054 P.R. China
| | - Dan He
- Department of Chemistry and Key Laboratory for, Preparation and Application of Ordered Structural Materials of, Guangdong Province Shantou University Guangdong 515063 P.R. China
| | - Zhong‐Yi Wang
- Department of Chemistry and Key Laboratory for, Preparation and Application of Ordered Structural Materials of, Guangdong Province Shantou University Guangdong 515063 P.R. China
| | - Cheng‐Yuan Luo
- Department of Chemistry and Key Laboratory for, Preparation and Application of Ordered Structural Materials of, Guangdong Province Shantou University Guangdong 515063 P.R. China
| | - Qing‐Xiao Tong
- Department of Chemistry and Key Laboratory for, Preparation and Application of Ordered Structural Materials of, Guangdong Province Shantou University Guangdong 515063 P.R. China
| | - Chun‐Sing Lee
- Center of Super-Diamond and Advanced Films (COSDAF) and Department of Chemistry City University of Hong Kong Hong Kong SAR P.R. China
| | - Si‐Lu Tao
- School of Optoelectronic Information University of Electronic Science and Technology of China (UESTC) Chengdu 610054 P.R. China
| |
Collapse
|
20
|
Konidena RK, Thomas KRJ, Pathak A, Dubey DK, Sahoo S, Jou JH. Tuning the Photophysical and Electroluminescence Properties in Asymmetrically Tetrasubstituted Bipolar Carbazoles by Functional Group Disposition. ACS APPLIED MATERIALS & INTERFACES 2018; 10:24013-24027. [PMID: 29931980 DOI: 10.1021/acsami.8b04566] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Carbazoles decorated with both donor and acceptor fragments offer a classical way to optimize bipolar functional properties. In this work, a series of carbazoles featuring triphenylamine donors and cyano acceptors are synthesized and their structure-property relationship is studied. The effects of connectivity and the chromophore number density on photophysical and electroluminescence properties are investigated. The position of the triphenylamine donor on the 3,6-dicyanocarbazole nucleus significantly affected the photophysical and electroluminescence properties. The dye possessing triphenylamine on C2 and C7 displayed a red shift in absorption when compared with the structural analogue with triphenylamine tethered to C1 and C8. The emission wavelength of the dyes are tunable from blue to green, by altering the position of triphenylamine and cyano substituents. All of the dyes exhibited positive solvatochromism in emission, attributable to the photoinduced intramolecular charge transfer from the triphenylamine donor to the cyano acceptor. However, the extent of charge transfer and hybridization of local and charge-transfer-excited states is highly dependent on the position of triphenylamine and cyano groups on the carbazole nucleus. Dyes containing cyano substituents at C2 and C7 showed a prolonged excited state lifetime, broad emission, and large Stokes shifts, indicating the presence of a higher charge transfer component in the excited state. The dyes displayed exceptional thermal stability with the onset decomposition temperature (10% weight loss) > 350 °C. Electrochemical measurements revealed low oxidation potential for dyes containing triphenylamine at C3 and/or C6. Addition of a cyano acceptor on carbazole led to the stabilization of lowest unoccupied molecular orbital. Furthermore, the materials were tested as emitting dopants in solution-processable multilayer organic light emitting diodes and found to display deep-blue/sky-blue electroluminescence with external quantum efficiency as high as 6.5% for a deep-blue emitter (CIE y ∼ 0.06).
Collapse
Affiliation(s)
- Rajendra Kumar Konidena
- Organic Materials Laboratory, Department of Chemistry , Indian Institute of Technology Roorkee , Roorkee 247 667 , India
| | - K R Justin Thomas
- Organic Materials Laboratory, Department of Chemistry , Indian Institute of Technology Roorkee , Roorkee 247 667 , India
| | - Ambika Pathak
- Organic Materials Laboratory, Department of Chemistry , Indian Institute of Technology Roorkee , Roorkee 247 667 , India
| | - Deepak Kumar Dubey
- Department of Material Science and Engineering , National Tsing Hua University , Hsinchu 30013 , Taiwan
| | - Snehasis Sahoo
- Department of Material Science and Engineering , National Tsing Hua University , Hsinchu 30013 , Taiwan
| | - Jwo-Huei Jou
- Department of Material Science and Engineering , National Tsing Hua University , Hsinchu 30013 , Taiwan
| |
Collapse
|
21
|
Affiliation(s)
- Fabio Rizzo
- Institute of Molecular Science and Technologies (ISTM); National Research Council (CNR); via Golgi 19 20133 Milano Italy
| | - Fabio Cucinotta
- School of Natural and Environmental Sciences; Newcastle University; Bedson Building 3.45 NE1 7RU Newcastle upon Tyne United Kingdom
| |
Collapse
|
22
|
Phenanthro[9′,10′:4,5]imidazo[2,1-a]isoquinoline derivatives containing phenoxazine moiety: Synthesis and photophysical properties. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2018.04.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
23
|
Peng S, Zhao Y, Fu C, Pu X, Zhou L, Huang Y, Lu Z. Acquiring High-Performance Deep-Blue OLED Emitters through an Unexpected Blueshift Color-Tuning Effect Induced by Electron-Donating -OMe Substituents. Chemistry 2018; 24:8056-8060. [PMID: 29655182 DOI: 10.1002/chem.201800974] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/05/2018] [Indexed: 11/11/2022]
Abstract
A series of blue-emissive 7-(diphenylamino)-4-phenoxycoumarin derivatives bearing -CF3 , -OMe, or -N(Me)2 substituents on the phenoxy subunit were synthesized. Although both the -CF3 and -N(Me)2 modifications were found to trigger redshifted fluorescence, the -OMe substitution was demonstrated to exert an unexpected blueshift color-tuning effect toward the deep-blue region. The reason is that the moderate electron-donating -OMe group can endow coumarins with unaltered HOMO but elevated LUMO energy levels. Moreover, the -OMe substitution was found to be beneficial to the thermal stability of these coumarins. Therefore, the trimethoxy-substituted objective compound can act as a high-performance deep-blue organic light-emitting diode (OLED) emitter, and OLED based on it emits deep-blue light with CIE coordinates of (0.148, 0.084), maximum luminance of 7800 cd m-2 , and maximum external quantum efficiency of 5.1 %. These results not only shed light on the molecular design strategy for high-performance deep-blue OLED emitters through color-tuning, but also show the perspective of coumarin derivatives as deep-blue OLED emitters.
Collapse
Affiliation(s)
- Song Peng
- Key Laboratory of Green Chemistry and Technology (Ministry of, Education), College of Chemistry, Sichuan University, Chengdu, 610064, P.R. China
| | - Yihuan Zhao
- Key Laboratory of Green Chemistry and Technology (Ministry of, Education), College of Chemistry, Sichuan University, Chengdu, 610064, P.R. China
| | - Caixia Fu
- Key Laboratory of Green Chemistry and Technology (Ministry of, Education), College of Chemistry, Sichuan University, Chengdu, 610064, P.R. China
| | - Xuemei Pu
- Key Laboratory of Green Chemistry and Technology (Ministry of, Education), College of Chemistry, Sichuan University, Chengdu, 610064, P.R. China
| | - Liang Zhou
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P.R. China
| | - Yan Huang
- Key Laboratory of Green Chemistry and Technology (Ministry of, Education), College of Chemistry, Sichuan University, Chengdu, 610064, P.R. China
| | - Zhiyun Lu
- Key Laboratory of Green Chemistry and Technology (Ministry of, Education), College of Chemistry, Sichuan University, Chengdu, 610064, P.R. China
| |
Collapse
|
24
|
Jayabharathi J, Ramya R, Thanikachalam V, Nethaji P. Optical and electroluminescent performances of dihydrobenzodioxin phenanthroimidazoles based blue-emitting materials. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2018.02.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
25
|
Zhao J, Liu B, Wang Z, Tong Q, Du X, Zheng C, Lin H, Tao S, Zhang X. EQE Climbing Over 6% at High Brightness of 14350 cd/m 2 in Deep-Blue OLEDs Based on Hybridized Local and Charge-Transfer Fluorescence. ACS APPLIED MATERIALS & INTERFACES 2018; 10:9629-9637. [PMID: 29498275 DOI: 10.1021/acsami.7b19646] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Three deep-blue emitters PPi-Pid, PPi-Xid, and PPi-Mid based on a novel conjugated system phenantroimidazole-π-indolizine have been designed and synthesized. Here, indolizine with appropriate π-conjugation length was used as the acceptor profited from its high-photoluminescence quantum yield and good electron-withdrawing ability. Fluorescent organic light-emitting diodes (OLEDs) based on PPi-Pid, PPi-Xid, and PPi-Mid achieved deep-blue emissions with the Commission Internationale de L'Eclairage coordinates of (0.151, 0.076), (0.155, 0.052), and (0.153, 0.052); high brightness of 14350, 4377, and 4002 cd/m2; and high external quantum efficiencies (EQEs) of 6.01, 3.90, and 4.28%, respectively. Moreover, it is noticeable that all of the devices exhibited efficiencies increasing with brightness. In particular, the PPi-Pid-based device exhibited high EQE over 6% at a high brightness of 14350 cd/m2. Such high brightness along with high EQE is very rare whether in deep-blue fluorescent or thermally activated delayed fluorescent OLEDs.
Collapse
Affiliation(s)
- Juewen Zhao
- School of Optoelectronic Information , University of Electronic Science and Technology of China (UESTC) , Chengdu 610054 , P. R. China
| | - Bin Liu
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province , Shantou University , Shantou , Guangdong 515063 , P. R. China
| | - Zhongyi Wang
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province , Shantou University , Shantou , Guangdong 515063 , P. R. China
| | - Qingxiao Tong
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province , Shantou University , Shantou , Guangdong 515063 , P. R. China
| | - Xiaoyang Du
- School of Optoelectronic Information , University of Electronic Science and Technology of China (UESTC) , Chengdu 610054 , P. R. China
| | - Caijun Zheng
- School of Optoelectronic Information , University of Electronic Science and Technology of China (UESTC) , Chengdu 610054 , P. R. China
| | - Hui Lin
- School of Optoelectronic Information , University of Electronic Science and Technology of China (UESTC) , Chengdu 610054 , P. R. China
| | - Silu Tao
- School of Optoelectronic Information , University of Electronic Science and Technology of China (UESTC) , Chengdu 610054 , P. R. China
| | - Xiaohong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM) , Soochow University , Suzhou 215123 , P. R. China
| |
Collapse
|
26
|
Liu Y, Hao Z, Jiang H, Liu Y, Wang Y, Tan H, Xie G. High-efficiency blue OLEDs based on dendritic dinuclear iridium (III) complexes grafted with fluorene core and blue fluorescence chromospheres. Tetrahedron 2018. [DOI: 10.1016/j.tet.2017.12.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
27
|
Jayabharathi J, Panimozhi S, Thanikachalam V. Hot exciton transition for organic light-emitting diodes: tailoring excited-state properties and electroluminescence performances of donor–spacer–acceptor molecules. RSC Adv 2018; 8:37324-37338. [PMID: 35557816 PMCID: PMC9088966 DOI: 10.1039/c8ra07891b] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 10/23/2018] [Indexed: 01/08/2023] Open
Abstract
The photophysical, electrochemical and electroluminescent properties of newly synthesized blue emitters with donor–π–acceptor geometry, namely, 4′-(1-(naphthalen-1-yl)-1H-phenanthro[9,10-d]imidazol-2-yl)-N,N-diphenyl-(2-[1,1′-biphenyl]vinyl)-4-amine (NSPI-TPA), 4′-(1-(2-methylnaphthalen-1-yl)-1H-phenanthro[9,10-d]imidazol-2-yl)-N,N-diphenyl-(2-[1,1′-biphenyl]vinyl)-4-amine (MNSPI-TPA), 4-(2-(4′-(diphenylamino)-(2-[1,1′-biphenyl]vinyl)-4-yl)-1H-phenanthro[9,10-d]imidazol-1-yl)-1-naphthalene-1-carbonitrile (SPNCN-TPA) and 4-(2-(4-(9H-carbazol-9-yl)styryl)-1H-phenanthro[9,10-d]imidazol-1-yl)naphthalene-1-carbonitrile (SPNCN-Cz) were analyzed. The conjugation length in the emitters is not conducive to pure emission and hence, a molecular twisting strategy was adopted in NSPI-TPA, MNSPI-TPA, SPNCN-TPA and SPNCN-Cz to enhance pure emission. The emissive state (HLCT) of twisted D–π–A molecules containing both LE and CT (HLCT) states was tuned for high PL (ηPL) (LE) and high exciton utilization (ηs) (CT) efficiencies by replacing triphenylamine (strong donor) with carbazole (weak donor). Among strong donor compounds, namely, NSPI-TPA, MNSPI-TPA and SPNCN-TPA, the SPNCN-TPA-based device exhibited blue emission (451 nm) with CIE coordinates (0.15, 0.08), maximum current efficiency (ηc) of 2.32 cd A−1, power efficiency (ηp) of 2.01 lm W−1 and external quantum efficiency (ηex) of 3.02%. The device with SPNCN-Cz emitter exhibited higher electroluminescence efficiencies than the SPNCN-TPA-based device, with pure blue emission (443 nm, CIE: 0.15,0.07), ηex of 3.15%, ηc of 2.56 cd A−1 and ηp of 2.45 lm W−1. SPNCN-Cz device exhibits ηex (3.15%), ηc (2.56 cd A−1), ηp (2.45 lm W−1) with CIE (0.15, 0.07).![]()
Collapse
|
28
|
Wang J, Liu Z, Yang S, Lin Y, Lin Z, Ling Q. Large Changes in Fluorescent Color and Intensity of Symmetrically Substituted Arylmaleimides Caused by Subtle Structure Modifications. Chemistry 2017; 24:322-326. [DOI: 10.1002/chem.201703652] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Jingwei Wang
- Fujian Key Laboratory of Polymer Materials; College of Chemistry and Materials Science; Fujian Normal University; No. 8 Shangsan Road Fuzhou 350007 China
| | - Zhengde Liu
- Fujian Key Laboratory of Polymer Materials; College of Chemistry and Materials Science; Fujian Normal University; No. 8 Shangsan Road Fuzhou 350007 China
| | - Shuming Yang
- Fujian Key Laboratory of Polymer Materials; College of Chemistry and Materials Science; Fujian Normal University; No. 8 Shangsan Road Fuzhou 350007 China
| | - Youzhi Lin
- Fujian Key Laboratory of Polymer Materials; College of Chemistry and Materials Science; Fujian Normal University; No. 8 Shangsan Road Fuzhou 350007 China
| | - Zhenghuan Lin
- Fujian Key Laboratory of Polymer Materials; College of Chemistry and Materials Science; Fujian Normal University; No. 8 Shangsan Road Fuzhou 350007 China
| | - Qidan Ling
- Fujian Key Laboratory of Polymer Materials; College of Chemistry and Materials Science; Fujian Normal University; No. 8 Shangsan Road Fuzhou 350007 China
| |
Collapse
|
29
|
Chen S, Wang L, Zhang J, Hao Z, Huang H, Deng GJ. Modular Synthesis of Carbazole-Based Conjugated Molecules through a One-Pot Annulation/Dehydrogenation Sequence. J Org Chem 2017; 82:11182-11191. [DOI: 10.1021/acs.joc.7b02305] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Shanping Chen
- Key Laboratory for Green
Organic Synthesis and Application of Hunan Province, Key Laboratory
of Environmentally Friendly Chemistry and Application of Ministry
of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Liren Wang
- Key Laboratory for Green
Organic Synthesis and Application of Hunan Province, Key Laboratory
of Environmentally Friendly Chemistry and Application of Ministry
of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Jing Zhang
- Key Laboratory for Green
Organic Synthesis and Application of Hunan Province, Key Laboratory
of Environmentally Friendly Chemistry and Application of Ministry
of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Zhaoran Hao
- Key Laboratory for Green
Organic Synthesis and Application of Hunan Province, Key Laboratory
of Environmentally Friendly Chemistry and Application of Ministry
of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Huawen Huang
- Key Laboratory for Green
Organic Synthesis and Application of Hunan Province, Key Laboratory
of Environmentally Friendly Chemistry and Application of Ministry
of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Guo-Jun Deng
- Key Laboratory for Green
Organic Synthesis and Application of Hunan Province, Key Laboratory
of Environmentally Friendly Chemistry and Application of Ministry
of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
| |
Collapse
|
30
|
Chen WC, Yuan Y, Xiong Y, Rogach AL, Tong QX, Lee CS. Aromatically C6- and C9-Substituted Phenanthro[9,10-d]imidazole Blue Fluorophores: Structure-Property Relationship and Electroluminescent Application. ACS APPLIED MATERIALS & INTERFACES 2017; 9:26268-26278. [PMID: 28692277 DOI: 10.1021/acsami.7b06547] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this study, a series of aromatically substituted phenanthro[9,10-d]imidazole (PI) fluorophores at C6 and C9 (no. 6 and 9 carbon atoms) have been synthesized and systematically characterized by theoretical, thermal, photophysical, electrochemical, and electroluminescent (EL) studies. C6 and C9 modifications have positive influences on the thermal properties of the new materials. Theoretical calculations suggest that the C6 and the C9 positions of PI are electronically different. Theoretical and experimental evidences of intramolecular charge transfer (ICT) between two identical moieties attaching to the C6 and the C9 positions are observed. Photophysical properties of the fluorophores are greatly influenced by size and conjugation extent of the substituents as well as linking steric hindrance. It is found that the C6 and C9 positions afford moderate conjugated extension compared to the C2 modification. Moreover, ICT characteristics of the new fluorophores increase as the size of the substituted aromatic group, and are partially influenced by steric hindrance, with the anthracene and the pyrene derivatives having the strongest ICT excited properties. EL performances of the fluorophores were evaluated as host emitters or dopants in organic light-emitting devices (OLEDs). Most of the devices showed significantly improved efficiencies compared to the OLED using the nonmodified emitter. Among all the devices, a 5 wt % TPI-Py doped device exhibited excellent performances with an external quantum efficiency >5% at 1000 cd/m2 and a deep-blue color index of (0.155, 0.065), which are comparable to the most advanced deep-blue devices. Our study can give useful information for designing C6/C9-modificated PI fluorophores and provide an efficient approach for constructing high-performance deep-blue OLEDs.
Collapse
Affiliation(s)
- Wen-Cheng Chen
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, Guangdong P.R. China
| | - Yi Yuan
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University , 243 University Road, Shantou, Guangdong 515063, P.R. China
| | | | | | - Qing-Xiao Tong
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University , 243 University Road, Shantou, Guangdong 515063, P.R. China
| | - Chun-Sing Lee
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, Guangdong P.R. China
| |
Collapse
|
31
|
Tang X, Shan T, Bai Q, Ma H, He X, Lu P. Efficient Deep-Blue Electroluminescence Based on Phenanthroimidazole-Dibenzothiophene Derivatives with Different Oxidation States of the Sulfur Atom. Chem Asian J 2017; 12:552-560. [DOI: 10.1002/asia.201601626] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/05/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Xiangyang Tang
- Department of Chemistry; Jilin University; State Key Laboratory of Supramolecular Structure and Materials; 2699 Qianjin Avenue Changchun 130012 P. R. China
| | - Tong Shan
- Department of Chemistry; Jilin University; State Key Laboratory of Supramolecular Structure and Materials; 2699 Qianjin Avenue Changchun 130012 P. R. China
| | - Qing Bai
- Department of Chemistry; Jilin University; State Key Laboratory of Supramolecular Structure and Materials; 2699 Qianjin Avenue Changchun 130012 P. R. China
| | - Hongwei Ma
- Department of Chemistry; Jilin University; State Key Laboratory of Supramolecular Structure and Materials; 2699 Qianjin Avenue Changchun 130012 P. R. China
| | - Xin He
- Department of Chemistry; Jilin University; State Key Laboratory of Supramolecular Structure and Materials; 2699 Qianjin Avenue Changchun 130012 P. R. China
| | - Ping Lu
- Department of Chemistry; Jilin University; State Key Laboratory of Supramolecular Structure and Materials; 2699 Qianjin Avenue Changchun 130012 P. R. China
| |
Collapse
|
32
|
Thanikachalam V, Sarojpurani E, Jayabharathi J, Jeeva P. Efficient phenanthroimidazole-styryl-triphenylamine derivatives for blue OLEDs: a combined experimental and theoretical study. NEW J CHEM 2017. [DOI: 10.1039/c6nj03801h] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Blue emitting devices based on 2-(4′-9H-carbazol-9-yl)-[1,1′-styryl]-4-yl-1-benzylpiperidine-1H-phenanthro[9,10-d]imidazole (Cz-BPIS) exhibits blue emission with CIE coordinates of (0.16, 0.09), current density of 1.91 cd/A, power efficiency of 1.63 lm/W and external quantum efficiency of 2.61%.
Collapse
Affiliation(s)
| | | | | | - Palanivel Jeeva
- Department of Chemistry
- Annamalai University
- Annamalainagar 608 002
- India
| |
Collapse
|
33
|
Li G, Zhao J, Zhang D, Zhu J, Shi Z, Tao S, Lu F, Tong Q. Non-doped deep blue emitters based on twisted phenanthroimidazole derivatives for organic light-emitting devices (CIE y ≈ 0.04). NEW J CHEM 2017. [DOI: 10.1039/c7nj00155j] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Three blue emitters via twisted donor–acceptor molecular design strategy show extremely good color purity without impairing the excellent photophysical and electrical properties. The color purity of nondoped devices can meet the blue OLED requirements of NTSC.
Collapse
Affiliation(s)
- Guang Li
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province
- Shantou University
- Guangdong 515063
- P. R. China
| | - Juewen Zhao
- School of Optoelectronic Information
- University of Electronic Science and Technology of China (UESTC)
- Chengdu 610054
- P. R. China
| | - Dan Zhang
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province
- Shantou University
- Guangdong 515063
- P. R. China
| | - Jieji Zhu
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province
- Shantou University
- Guangdong 515063
- P. R. China
| | - Zhichun Shi
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province
- Shantou University
- Guangdong 515063
- P. R. China
| | - Silu Tao
- School of Optoelectronic Information
- University of Electronic Science and Technology of China (UESTC)
- Chengdu 610054
- P. R. China
| | - Feng Lu
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province
- Shantou University
- Guangdong 515063
- P. R. China
| | - Qingxiao Tong
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province
- Shantou University
- Guangdong 515063
- P. R. China
| |
Collapse
|
34
|
Kumar Konidena R, Justin Thomas KR, Kumar Dubey D, Sahoo S, Jou JH. A new molecular design based on hybridized local and charge transfer fluorescence for highly efficient (>6%) deep-blue organic light emitting diodes. Chem Commun (Camb) 2017; 53:11802-11805. [DOI: 10.1039/c7cc07139f] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A new molecular design featuring a carbazole-derivative as an acceptor and a triphenylamine donor and displaying hybridized local and charge transfer (HLCT) fluorescence is demonstrated.
Collapse
Affiliation(s)
- Rajendra Kumar Konidena
- Organic Materials Laboratory, Department of Chemistry, Indian Institute of Technology Roorkee
- Roorkee
- India
| | - K. R. Justin Thomas
- Organic Materials Laboratory, Department of Chemistry, Indian Institute of Technology Roorkee
- Roorkee
- India
| | - Deepak Kumar Dubey
- Department of Material Science and Engineering, National Tsing Hua University
- Hsinchu
- Taiwan
| | - Snehasis Sahoo
- Department of Material Science and Engineering, National Tsing Hua University
- Hsinchu
- Taiwan
| | - Jwo-Huei Jou
- Department of Material Science and Engineering, National Tsing Hua University
- Hsinchu
- Taiwan
| |
Collapse
|
35
|
You DK, Lee SH, Lee JH, Kwak SW, Hwang H, Lee J, Chung Y, Park MH, Lee KM. Synthesis and photophysical properties of phenanthroimidazole–triarylborane dyads: intriguing ‘turn-on’ sensing mediated by fluoride anions. RSC Adv 2017. [DOI: 10.1039/c6ra28559g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Phenanthroimidazole-based triarylborane compounds with an N-phenyl or N-biphenyl bridge were prepared and these compounds show ratiometrical ‘turn-on’ response in PL spectra upon fluoride binding to the borane moiety.
Collapse
Affiliation(s)
- Dong Kyun You
- Department of Chemistry
- Institute for Molecular Science and Fusion Technology
- Kangwon National University
- Chuncheon
- Republic of Korea
| | - Seon Hee Lee
- Department of Chemistry Education
- Chungbuk National University
- Cheongju
- Republic of Korea
| | - Ji Hye Lee
- Department of Chemistry
- Institute for Molecular Science and Fusion Technology
- Kangwon National University
- Chuncheon
- Republic of Korea
| | - Sang Woo Kwak
- Department of Chemistry
- Chungbuk National University
- Cheongju
- Republic of Korea
| | - Hyonseok Hwang
- Department of Chemistry
- Institute for Molecular Science and Fusion Technology
- Kangwon National University
- Chuncheon
- Republic of Korea
| | - Junseong Lee
- Department of Chemistry
- Chonnam National University
- Gwangju 61186
- Republic of Korea
| | - Yongseog Chung
- Department of Chemistry
- Chungbuk National University
- Cheongju
- Republic of Korea
| | - Myung Hwan Park
- Department of Chemistry Education
- Chungbuk National University
- Cheongju
- Republic of Korea
| | - Kang Mun Lee
- Department of Chemistry
- Institute for Molecular Science and Fusion Technology
- Kangwon National University
- Chuncheon
- Republic of Korea
| |
Collapse
|