Oxadiazole-Based Highly Efficient Bipolar Fluorescent Emitters for Organic Light-Emitting Diodes
Abstract
1. Introduction
2. Results and Discussion
2.1. Synthesis
2.2. Thermal Properties
2.3. Photophysical and Electrochemical Properties
2.4. Device Characteristics
3. Materials and Methods
3.1. General Procedures
3.2. Synthetic Procedures
3.2.1. 4-Bromo-N′-(4-bromobenzoyl)benzohydrazide (1)
3.2.2. 2,5-Bis(4-bromophenyl)-1,3,4-oxadiazole (2)
3.2.3. 2-(4-Bromophenyl)-5-phenyl-1,3,4-oxadiazole (4)
3.2.4. 2,5-Bis(4-(9,9-diphenyl-9,10-dihydroacridine)phenyl)-1,3,4-oxadiazole (2DPAc-OXD)
3.2.5. 2-(4-(9,9-Diphenyl-9,10-dihydroacridine)phenyl)-1,3,4-oxadiazole (DPAc-OXD)
3.2.6. 2,5-Bis(4-(10H-phenothiazin-10-yl)-1,3,4-oxadizole (2PTZ-OXD)
3.2.7. 2-(4-(10H-phenothiazin-10-yl)-1,3,4-oxadiazole(PTZ-OXD)
3.3. OLED Fabrication and Characterization
4. Conclusions
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Sample Availability: Samples of the compounds are not available from the authors. |
Dopant | Td a (°C) | UV-vis b (nm) | PL max c (nm) | HOMO d (eV) | LUMO e (eV) | Eg f (eV) | ET g (eV) |
---|---|---|---|---|---|---|---|
PTZ-OXD 2PTZ-OXD DPAc-OXD 2DPAc-OXD | 358 419 375 455 | 376 384 396 402 | 500 512 435 442 | −5.48 −5.48 −5.69 −5.68 | −2.18 −2.25 −2.56 −2.60 | 3.30 3.23 3.13 3.08 | 2.48 2.42 2.85 2.81 |
Calculation Values | PTZ-OXD | 2PTZ-OXD | DPAc-OXD | 2DPAc-OXD |
---|---|---|---|---|
S1 (eV) a T1 (eV) b ΔEST (eV) c D-A rotation(°) HOMO (eV) LUMO (eV) | 3.71 3.36 0.35 77.05 −5.975 −2.185 | 3.63 3.34 0.29 78.91 −5.485 −2.255 | 3.83 3.37 0.46 81.26 −5.695 −2.565 | 3.78 3.34 0.44 81.70 −5.685 −2.605 |
Device properties | PTZ-OXD | 2PTZ-OXD | DPAc-OXD | 2DPAc-OXD |
---|---|---|---|---|
Turn on voltage (V) | 4.4 a 6.0 b | 4.2 a 5.6 b | 4.1 a 6.0 b | 4.1 a 6.2 b |
Driving voltage (V) | 6.8 a | 5.9 a | 7.6 a | 7.5 a |
Current (mA) | 0.05 a 0.05 b | 0.03 a 0.03 b | 0.04 a 0.06 b | 0.05 a 0.10 b |
Current efficiency (cd/A) | 5.03 a 4.97 b | 9.20 a 10.10 b | 1.30 a 0.72 b | 1.28 a 0.66 b |
Power efficiency (Lm/W) | 3.59 a 2.60 b | 6.88 a 5.67 b | 0.99 a 0.38 b | 0.98 a 0.33 b |
EQE (%) | 1.94 a | 3.38 a | 1.84 a | 1.81 a |
2.26 b | 3.99 b | 1.08 b | 0.88 b | |
Luminance (at 1000 cd/m2) | 1008 | 1020 | 1029 | 992 |
CIE (x,y) | (0.38, 0.50) a (0.43, 0.14) b | (0.40, 0.53) a (0.31, 0.49) b | (0.16, 0.12) a (0.18, 0.12) b | (0.17, 0.14) a (0.18, 0.15) b |
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Wu, Q.; Braveenth, R.; Zhang, H.Q.; Bae, I.-J.; Kim, M.; Chai, K.Y. Oxadiazole-Based Highly Efficient Bipolar Fluorescent Emitters for Organic Light-Emitting Diodes. Molecules 2018, 23, 843. https://doi.org/10.3390/molecules23040843
Wu Q, Braveenth R, Zhang HQ, Bae I-J, Kim M, Chai KY. Oxadiazole-Based Highly Efficient Bipolar Fluorescent Emitters for Organic Light-Emitting Diodes. Molecules. 2018; 23(4):843. https://doi.org/10.3390/molecules23040843
Chicago/Turabian StyleWu, Qiong, Ramanaskanda Braveenth, Heng Qiang Zhang, Il-Ji Bae, Miyoung Kim, and Kyu Yun Chai. 2018. "Oxadiazole-Based Highly Efficient Bipolar Fluorescent Emitters for Organic Light-Emitting Diodes" Molecules 23, no. 4: 843. https://doi.org/10.3390/molecules23040843
APA StyleWu, Q., Braveenth, R., Zhang, H. Q., Bae, I.-J., Kim, M., & Chai, K. Y. (2018). Oxadiazole-Based Highly Efficient Bipolar Fluorescent Emitters for Organic Light-Emitting Diodes. Molecules, 23(4), 843. https://doi.org/10.3390/molecules23040843