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Efficient deep red phosphorescent OLEDs using 1,2,4-thiadiazole core-based novel bipolar host with low efficiency roll-off

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Abstract

A series of 1,2,4-thiadiazole core-based bipolar materials, 2,2′-(1,2,4-thiadiazole-3,5-diyl)bis(N,N-diphenylaniline) (o-TPATHZ), 3,3′-(1,2,4-thiadiazole-3,5-diyl)bis(N,N-diphenylaniline) (m-TPATHZ) and 4,4′-(1,2,4-thiadiazole-3,5-diyl)bis(N,N-diphenylaniline) (p-TPATHZ) were developed as the host matrixes for the deep red phosphorescent emitters tris(1-phenylisoqiunoline) iridium (Ir(piq)3) and [bis(2-methyldibenzo-[f,h]-quinoxaline) Ir(III)(acetylacetonate)] (Ir(MDQ)2(acac)). By systematic studying, we demonstrated that there are two types of charge-trapping effect within the emissive layers through adjusting the host-guest compatibility. And, it is revealed that a symmetric charge-trapping effect can contribute to realizing a stable charge-balance, which led to a mitigating efficiency roll-off at high current density. Consequently, a maximum external quantum efficiency (EQE) of 16.2% was achieved by an optimized device with p-TPATHZ-Ir(piq)3 emissive layer. Remarkably, the EQE still remained as high as 15.7% at the high luminance of 1000 cd/m2.

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References

  1. Forrest S R. The path to ubiquitous and low-cost organic electronic appliances on plastic. Nature, 2004, 428(6986): 911–918

    Article  Google Scholar 

  2. Sasabe H, Kido J. Development of high performance OLEDs for general lighting. Journal of Materials Chemistry C, Materials for Optical and Electronic Devices, 2013, 1(9): 1699–1707

    Article  Google Scholar 

  3. Reineke S, Lindner F, Schwartz G, Seidler N, Walzer K, Lüssem B, Leo K. White organic light-emitting diodes with fluorescent tube efficiency. Nature, 2009, 459(7244): 234–238

    Article  Google Scholar 

  4. Xiao L, Chen Z, Qu B, Luo J, Kong S, Gong Q, Kido J. Recent progresses on materials for electrophosphorescent organic lightemitting devices. Advanced Materials, 2011, 23(8): 926–952

    Article  Google Scholar 

  5. Ma Y, Zhang H, Shen J, Che C. Electroluminescence from triplet metal-ligand charge-transfer excited state of transition metal complexes. Synthetic Metals, 1998, 94(3): 245–248

    Article  Google Scholar 

  6. Baldo MA, O’brien D F, You Y, Shoustikov A, Sibley S, Thompson M E, Forrest S R. Highly efficient phosphorescent emission from organic electroluminescent devices. Nature, 1998, 395(6698): 151–154

    Article  Google Scholar 

  7. Yang X, Zhou G, Wong W Y. Functionalization of phosphorescent emitters and their host materials by main-group elements for phosphorescent organic light-emitting devices. Chemical Society Reviews, 2015, 44(23): 8484–8575

    Article  Google Scholar 

  8. Zhuang S, Zhang W, Yang X, Wang L. A simple unilateral homogenous PhOLEDs with enhanced efficiency and reduced efficiency roll-off. Frontiers of Optoelectronics, 2013, 6(4): 435–439

    Article  Google Scholar 

  9. Hussain A, Zerin T, Khan M A. Design and simulation to improve the structural efficiency of green light emission of GaN/InGaN/AlGaN light emitting diode. Frontiers of Optoelectronics, 2017, 10 (4): 370–377

    Google Scholar 

  10. Hu X, Xia X, Zhou L, Zhang L, Wu W. Design of compensation pixel circuit with In-Zn-O thin film transistor for active-matrix organic light-emitting diode 3D display. Frontiers of Optoelectronics, 2017, 10(1): 45–50

    Article  Google Scholar 

  11. Baldo MA, Lamansky S, Burrows P E, Thompson ME, Forrest S R. Very high-efficiency green organic light-emitting devices based on electrophosphorescence. Applied Physics Letters, 1999, 75(1): 4–6

    Article  Google Scholar 

  12. Kim K H, Lee S, Moon C K, Kim S Y, Park Y S, Lee J H, Woo Lee J, Huh J, You Y, Kim J J. Phosphorescent dye-based supramolecules for high-efficiency organic light-emitting diodes. Nature Communications, 2014, 5(1): 4769–4777

    Article  Google Scholar 

  13. Chen J, Zhao F, Ma D. Hybrid white OLEDs with fluorophors and phosphors. Materials Today, 2014, 17(4): 175–183

    Article  Google Scholar 

  14. Xiang C, Koo W, So F, Sasabe H, Kido J. A systematic study on efficiency enhancements in phosphorescent green, red and blue microcavity organic light emitting devices. Light, Science & Applications, 2013, 2(6): 74–81

    Article  Google Scholar 

  15. Jeon S O, Jang S E, Son H S, Lee J Y. External quantum efficiency above 20% in deep blue phosphorescent organic light-emitting diodes. Advanced Materials, 2011, 23(12): 1436–1441

    Article  Google Scholar 

  16. Lee C W, Lee J Y. Above 30% external quantum efficiency in blue phosphorescent organic light-emitting diodes using pyrido[2,3-b] indole derivatives as host materials. Advanced Materials, 2013, 25 (38): 5450–5454

    Google Scholar 

  17. Adachi C, Baldo M A, Thompson M E, Forrest S R. Nearly 100% internal phosphorescence efficiency in an organic light-emitting device. Journal of Applied Physics, 2001, 90(10): 5048–5051

    Article  Google Scholar 

  18. Tao Y T, Wang Q, Yang C L, Zhong C, Qin J G, Ma D G. Multifunctional triphenylamine/oxadiazole hybrid as host and exciton-blocking material: high efficiency green phosphorescent OLEDs using easily available and common materials. Advanced Functional Materials, 2010, 20(17): 2923–2929

    Article  Google Scholar 

  19. Fan C H, Sun P, Su T H, Cheng C H. Host and dopant materials for idealized deep-red organic electrophosphorescence devices. Advanced Materials, 2011, 23(26): 2981–2985

    Article  Google Scholar 

  20. Jou J H, Su Y T, Hsiao M T, Yu H H, He Z K, Fu S C, Chiang C H, Chen C T, Chou C H, Shyue J J. Solution-process-feasible deep-red phosphorescent emitter. Journal of Physical Chemistry C, 2016, 120 (33): 18794–18802

    Google Scholar 

  21. Caspar J V, Meyer T J. Application of the energy gap law to nonradiative, excited-state decay. Journal of Physical Chemistry, 1983, 87(6): 952–957

    Article  Google Scholar 

  22. Kim D H, Cho N S, Oh H Y, Yang J H, Jeon W S, Park J S, Suh M C, Kwon J H. Highly efficient red phosphorescent dopants in organic light-emitting devices. Advanced Materials, 2011, 23(24): 2721–2726

    Article  Google Scholar 

  23. Jiang B, Gu Y, Qin J J, Ning X W, Gong S L, Xie G H, Yang C L. Deep-red iridium (III) complexes cyclometalated by phenanthridine derivatives for highly efficient solution-processed organic lightemitting diodes. Journal of Materials Chemistry C, Materials for Optical and Electronic Devices, 2016, 4(16): 3492–3498

    Article  Google Scholar 

  24. Cho W, Sarada G, Lee H, Song M, Gal Y S, Lee Y, Jin S H. Highly efficient, conventional and flexible deep-red phosphorescent OLEDs using ambipolar thiophene/selenophene-phenylquinoline ligand-based Ir(III) complexes. Dyes and Pigments, 2017, 136: 390–397

    Article  Google Scholar 

  25. Cheng S H, Hung W Y, Cheng M H, Chen H F, Lee G H, Chung C L, Yeh T C, Tang W C, Huang S L, Wong K T. Highly twisted carbazole-oxadiazole hybrids as universal bipolar hosts for high efficiency PhOLEDs. Advanced Electronic Materials, 2016, 2(1): 1500241

    Article  Google Scholar 

  26. Wang L, Pan B, Zhu L, Wang B, Wang Y, Liu Y, Jin J, Chen J, Ma D. Construction of thermally stable 3,6-disubstituted spiro-fluorene derivatives as host materials for blue phosphorescent organic lightemitting diodes. Dyes and Pigments, 2015, 114: 222–230

    Article  Google Scholar 

  27. Byeon S Y, Lee J Y. High-triplet-energy host materials derived from directly-coupled carbazole-pyridoindole moieties. Dyes and Pigments, 2016, 130: 183–190

    Article  Google Scholar 

  28. Seo C W, Yoon J H, Lee J Y. Engineering of charge transport materials for universal low optimum doping concentration in phosphorescent organic light-emitting diodes. Organic Electronics, 2012, 13(2): 341–349

    Article  Google Scholar 

  29. Luo Y, Aziz H. Correlation between triplet-triplet annihilation and electroluminescence efficiency in doped fluorescent organic lightemitting devices. Advanced Functional Materials, 2010, 20(8): 1285–1293

    Article  Google Scholar 

  30. Kawamura Y, Brooks J, Brown J J, Sasabe H, Adachi C. Intermolecular interaction and a concentration-quenching mechanism of phosphorescent Ir(III) complexes in a solid film. Physical Review Letters, 2006, 96(1): 017404

    Article  Google Scholar 

  31. Tao Y, Wang Q, Yang C, Wang Q, Zhang Z, Zou T, Qin J, Ma D. A simple carbazole/oxadiazole hybrid molecule: an excellent bipolar host for green and red phosphorescent OLEDs. Angewandte Chemie, 2008, 47(42): 8104–8107

    Article  Google Scholar 

  32. Li C, Duan L, Li H Y, Qiu Y. Universal trap effect in carrier transport of disordered organic semiconductors: transition from shallow trapping to deep trapping. Journal of Physical Chemistry C, 2014, 118(20): 10651–10660

    Article  Google Scholar 

  33. Li C, Duan L, Sun Y D, Li H Y, Qiu Y. Charge transport in mixed organic disorder semiconductors: trapping, scattering, and effective energetic disorder. Journal of Physical Chemistry C, 2012, 116(37): 19748–19754

    Article  Google Scholar 

  34. Zhang W Z, Jin J J, Huang Z, Lv X, Zhuang S, Wang L. Towards highly efficient thermally activated delayed fluorescence devices through a trap-assisted recombination mechanism and reduced interfacial exciton annihilation. Journal of Materials Chemistry C, Materials for Optical and Electronic Devices, 2017, 5(19): 4636–4644

    Article  Google Scholar 

  35. Alonso F, Beletskaya I P, Yus M. Non-conventional methodologies for transition-metal catalysed carbon–carbon coupling: a critical overview. Part 2: The Suzuki reaction. Tetrahedron, 2008, 64(14): 3047–3101

    Google Scholar 

  36. Jin J J, Zhang W Z, Wang B, Mu G Y, Xu P, Wang L, Huang H, Chen J S, Ma D G. Construction of high Tg bipolar host materials with balanced electron–hole mobility based on 1, 2, 4-thiadiazole for phosphorescent organic light-emitting diodes. Chemistry of Materials, 2014, 26(7): 2388–2395

    Article  Google Scholar 

  37. Fan C, Chen Y, Liu Z, Jiang Z, Zhong C, Ma D, Qin J, Yang C. Tetraphenylsilane derivatives spiro-annulated by triphenylamine/carbazole with enhanced HOMO energy levels and glass transition temperatures without lowering triplet energy: host materials for efficient blue phosphorescent OLEDs. Journal of Materials Chemistry C, Materials for Optical and Electronic Devices, 2013, 1(3): 463–469

    Article  Google Scholar 

  38. Lee D R, Choi J M, Lee C W, Lee J Y. Ideal molecular design of blue thermally activated delayed fluorescent emitter for high efficiency, small singlet–triplet energy splitting, low efficiency roll-off, and long lifetime. ACS Applied Materials & Interfaces, 2016, 8(35): 23190–23196

    Article  Google Scholar 

  39. Lee C, Yang W, Parr R G. Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density. Physical Review B, 1988, 37(2): 785–789

    Article  Google Scholar 

  40. Boese A D, Handy N C. New exchange-correlation density functionals: the role of the kinetic-energy density. Journal of Chemical Physics, 2002, 116(22): 9559–9569

    Article  Google Scholar 

  41. Chang Y L, Wang Z B, Helander M G, Qiu J, Puzzo D P, Lu Z H. Enhancing the efficiency of simplified red phosphorescent organic light emitting diodes by exciton harvesting. Organic Electronics, 2012, 13(5): 925–931

    Article  Google Scholar 

  42. Jeon W S, Park T J, Kim S Y, Pode R, Jang J, Kwon J H. Ideal host and guest system in phosphorescent OLEDs. Organic Electronics, 2009, 10(2): 240–246

    Article  Google Scholar 

  43. Su S J, Cai C, Kido J. Three-carbazole-armed host materials with various cores for RGB phosphorescent organic light-emitting diodes. Journal of Materials Chemistry, 2012, 22(8): 3447–3456

    Article  Google Scholar 

  44. Su S J, Cai C, Kido J. RGB phosphorescent organic light-emitting diodes by using host materials with heterocyclic cores: effect of nitrogen atom orientations. Chemistry of Materials, 2011, 23(2): 274–284

    Article  Google Scholar 

Download references

Acknowledgements

This research work was supported by the National Natural Science Foundation of China (Grant Nos. 51573065 and 51727809), China Postdoctoral Science Foundation (No. 2017M620321), the science and technology support program of Hubei Province (No. 2015BAA075), the Fundamental Research Funds for the Central Universities, HUST (No. 2018KFYXKJC043). Thanks to SCTS/CGCL HPCC of HUST for providing computing resources and technical support. The Analytical and Testing Center at Huazhong University of Science and Technology is acknowledged for characterization of new compounds.

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Authors and Affiliations

  1. Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China

    Runda Guo, Wenzhi Zhang, Qing Zhang, Xialei Lv & Lei Wang

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  1. Runda Guo
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  2. Wenzhi Zhang
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  3. Qing Zhang
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  4. Xialei Lv
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  5. Lei Wang
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Correspondence to Lei Wang.

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Lei Wang is a professor in Wuhan National Laboratory for Optoelectronics (WNLO) in Huazhong University of Science and Technology (HUST). His research is focused on the area of organic light emitting diode (OLED) and quantum light emitting diode (QLED). More specifically, he is currently working on 1) the development of TADF material and device; 2) investigating small molecules that are able to harvest dark triplet state in OLED; 3) the development of the perovskite nanocrystal and its application in LED. He has published>70 articles in peer reviewed international journals.

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Guo, R., Zhang, W., Zhang, Q. et al. Efficient deep red phosphorescent OLEDs using 1,2,4-thiadiazole core-based novel bipolar host with low efficiency roll-off. Front. Optoelectron. 11, 375–384 (2018). https://doi.org/10.1007/s12200-018-0855-4

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