Efficient Blue Electroluminescence with an External Quantum Efficiency of 9.20% and CIE < 0.08 Without Excimer Emission

Overview

Journal RSC Adv

Publisher Royal Society of Chemistry

Specialty Chemistry

Date 2022 May 6

PMID 35517441

Authors

Jayaraman Jayabharathi

Sekar Sivaraj

Venugopal Thanikachalam

Balu Seransenguttuvan

Affiliations

Soon will be listed here.

Abstract

Aromatically substituted phenanthroimidazoles at the C6 and C9 positions enhanced the thermal, photochemical and electroluminescence properties due to extension of conjugation. These new materials exhibit good photophysical properties with high thermal stability, good film-forming property and high luminous efficiency. The electroluminescence performances of C6 and C9 modified phenanthroimidazoles as host emitters were evaluated as well as the dopant in the fabricated devices. Among the non-doped devices, pyrene substituted PPI-Py or PPICN-Py based devices show maximum efficiency: PPI-Py/PPICN-Py: (cd A) - 9.20/9.98; (lm W) - 8.50/9.16; (%) - 5.56/5.80. The doped OLEDs, -MTDATA/TAPC:PPI-Cz (4.81/4.85%), -MTDATA/TAPC:PPICN-Cz (5.23/5.26%), -MTDATA/TAPC:PPI-An (5.01/5.04%), -MTDATA/TAPC:PPICN-An (5.25/5.28%), -MTDATA/TAPC:PPI-Py (5.61/5.65%) and -MTDATA/TAPC:PPICN-Py (5.76/5.78%) show improved device efficiencies compared to non-doped devices. Designing C6/C9 modified phenanthrimidazole fluorophores is an efficient strategy for constructing highly efficient OLEDs.

Citing Articles

Observation of aligned dipoles and angular chromism of exciplexes in organic molecular heterostructures.

Lee S, Kim T, Lee E, Kwon D, Kim J, Joo J Nat Commun. 2023; 14(1):7190.

PMID: 37938244 PMC: 10632441. DOI: 10.1038/s41467-023-42976-y.

References

Chen L, Jiang Y, Nie H, Hu R, Kwok H, Huang F . Rational design of aggregation-induced emission luminogen with weak electron donor-acceptor interaction to achieve highly efficient undoped bilayer OLEDs. ACS Appl Mater Interfaces. 2014; 6(19):17215-25. DOI: 10.1021/am505036a. View

Grabowski Z, Rotkiewicz K, Rettig W . Structural changes accompanying intramolecular electron transfer: focus on twisted intramolecular charge-transfer states and structures. Chem Rev. 2003; 103(10):3899-4032. DOI: 10.1021/cr940745l. View

Li C, Wang S, Chen W, Wei J, Yang G, Ye K . High performance full color OLEDs based on a class of molecules with dual carrier transport channels and small singlet-triplet splitting. Chem Commun (Camb). 2015; 51(53):10632-5. DOI: 10.1039/c5cc03492b. View

Shirota Y, Kageyama H . Charge carrier transporting molecular materials and their applications in devices. Chem Rev. 2007; 107(4):953-1010. DOI: 10.1021/cr050143+. View

Riano A, Arrechea-Marcos I, Mancheno M, Mayorga Burrezo P, De la Pena A, Loser S . Benzotrithiophene versus Benzo/Naphthodithiophene Building Blocks: The Effect of Star-Shaped versus Linear Conjugation on Their Electronic Structures. Chemistry. 2016; 22(18):6374-81. DOI: 10.1002/chem.201504526. View

Chen W, Yuan Y, Ni S, Zhu Z, Zhang J, Jiang Z . Highly Efficient Deep-Blue Electroluminescence from a Charge-Transfer Emitter with Stable Donor Skeleton. ACS Appl Mater Interfaces. 2017; 9(8):7331-7338. DOI: 10.1021/acsami.6b14638. View

Obolda A, Peng Q, He C, Zhang T, Ren J, Ma H . Triplet-Polaron-Interaction-Induced Upconversion from Triplet to Singlet: a Possible Way to Obtain Highly Efficient OLEDs. Adv Mater. 2016; 28(23):4740-6. DOI: 10.1002/adma.201504601. View

Kondrasenko I, Tsai Z, Chung K, Chen Y, Ershova Y, Domenech-Carbo A . Ambipolar Phosphine Derivatives to Attain True Blue OLEDs with 6.5% EQE. ACS Appl Mater Interfaces. 2016; 8(17):10968-76. DOI: 10.1021/acsami.6b01041. View

Jayabharathi J, Anudeebhana J, Thanikachalam V, Sivaraj S, Prabhakaran A . Efficient donor-acceptor emitter based nonsymmetrical connection for organic emitting diodes with improving exciton utilization. RSC Adv. 2022; 10(7):4002-4013. PMC: 9049240. DOI: 10.1039/c9ra10513a. View

10.

Lu T, Chen F . Multiwfn: a multifunctional wavefunction analyzer. J Comput Chem. 2011; 33(5):580-92. DOI: 10.1002/jcc.22885. View

11.

Francke R, Little R . Optimizing electron transfer mediators based on arylimidazoles by ring fusion: synthesis, electrochemistry, and computational analysis of 2-aryl-1-methylphenanthro[9,10-d]imidazoles. J Am Chem Soc. 2013; 136(1):427-35. DOI: 10.1021/ja410865z. View

12.

Melkonyan F, Zhao W, Drees M, Eastham N, Leonardi M, Butler M . Bithiophenesulfonamide Building Block for π-Conjugated Donor-Acceptor Semiconductors. J Am Chem Soc. 2016; 138(22):6944-7. DOI: 10.1021/jacs.6b03498. View

13.

Cho M, Kim S, Yoon S, Shin J, Hong T, Kim H . New bipolar host materials for realizing blue phosphorescent organic light-emitting diodes with high efficiency at 1000 cd/m2. ACS Appl Mater Interfaces. 2014; 6(22):19808-15. DOI: 10.1021/am505049h. View

14.

Chen W, Yuan Y, Ni S, Tong Q, Wong F, Lee C . Achieving efficient violet-blue electroluminescence with CIE <0.06 and EQE >6% from naphthyl-linked phenanthroimidazole-carbazole hybrid fluorophores. Chem Sci. 2018; 8(5):3599-3608. PMC: 6094158. DOI: 10.1039/c6sc05619a. View

15.

Wu H, Yu A, Lee W, Liu C, Chen W . A poly(fluorene-thiophene) donor with a tethered phenanthro[9,10-d]imidazole acceptor for flexible nonvolatile flash resistive memory devices. Chem Commun (Camb). 2012; 48(73):9135-7. DOI: 10.1039/c2cc34257j. View

16.

Wang Z, Lou Y, Naka S, Okada H . Direct comparison of solution- and vacuum-processed small molecular organic light-emitting devices with a mixed single layer. ACS Appl Mater Interfaces. 2011; 3(7):2496-503. DOI: 10.1021/am2003729. View

17.

Lyu Y, Kwak J, Kwon O, Lee S, Kim D, Lee C . Silicon-cored anthracene derivatives as host materials for highly efficient blue organic light-emitting devices. Adv Mater. 2014; 20(14):2720-9. DOI: 10.1002/adma.200602885. View

18.

Tseng C, Tzeng C, Shih P, Yang C, Chuang Y, Peng S . Identification of furo[3', 2':3,4]naphtho[1,2-d]imidazole derivatives as orally active and selective inhibitors of microsomal prostaglandin E(2) synthase-1 (mPGES-1). Mol Divers. 2011; 16(2):215-29. DOI: 10.1007/s11030-011-9347-9. View

19.

Zhang S, Li W, Yao L, Pan Y, Shen F, Xiao R . Enhanced proportion of radiative excitons in non-doped electro-fluorescence generated from an imidazole derivative with an orthogonal donor-acceptor structure. Chem Commun (Camb). 2013; 49(96):11302-4. DOI: 10.1039/c3cc47130f. View

20.

Wang Z, Feng Y, Zhang S, Gao Y, Gao Z, Chen Y . Construction of high efficiency non-doped deep blue emitters based on phenanthroimidazole: remarkable substitution effects on the excited state properties and device performance. Phys Chem Chem Phys. 2014; 16(38):20772-9. DOI: 10.1039/c4cp03284e. View