Pyridine-Incorporated Dihexylquaterthiophene: A Novel Blue Emitter for Organic Light Emitting Diodes (OLEDs)
Prashant Sonar A D , Sonsoles Garcia Santamaria B , Ting Ting Lin A , Alan Sellinger A C and Henk Bolink BA Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore 117602.
B Instituto de Ciencia Molécula, Universidad de Valencia, PO Box 22085, 46071 Valencia, Spain.
C Current address: Department of Materials Science and Engineering and the Center for Advanced Molecular Photovoltaics (CAMP), Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA 94305-4045, USA.
D Corresponding author. Email: sonarp@imre.a-star.edu.sg
Australian Journal of Chemistry 65(9) 1244-1251 https://doi.org/10.1071/CH12171
Submitted: 26 March 2012 Accepted: 24 May 2012 Published: 3 July 2012
Abstract
The synthesis and characterisation of 2,5-bis(5′-hexyl-[2,2′-bithiophen]-5-yl)pyridine (Th4PY) and its use as a blue emitter in organic light emitting diodes (OLEDs) is reported. Th4PY was synthesised in high yield using a straightforward Suzuki coupling route with commercially available starting materials. As Th4PY is both soluble and has low molecular weight, blue OLEDs were fabricated using both spin-coating and vacuum deposition thin film processing techniques to study the effect of processing on device performance. OLED devices using a spin-coated layer consisting of 4′,4′′-tris(N-carbazolyl)triphenylamine (TCTA) and 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) as a host matrix together with Th4PY as emitter exhibited highly efficient sky-blue emission with a low turn-on voltage of 3 V, a maximum brightness close to 15000 cd m–2 at 8 V, and a maximum luminous efficiency of 7.4 cd A–1 (6.3 lm W–1) with CIE coordinates of x = 0.212, y = 0.320. The device performance characteristics are compared using various matrices and processing techniques. The promising sky-blue OLED performance, solution processability, and ambient stability make Th4PY a promising blue emitter for application in OLEDs.
References
[1] Y. Shirota, H. Kageyama, Chem. Rev. 2007, 107, 953.| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXjvFyjsLo%3D&md5=3567b53d460954be36191b8d368bb948CAS |
[2] F. So, J. Kido, P. Burrows, MRS Bull. 2008, 33, 663.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtVSjtLvJ&md5=952ffb9428d67a27ab246c6ec4954838CAS |
[3] A. R. Duggal, C. M. Heller, J. J. Shiang, J. Liu, L. N. Lewis, J. Disp. Technol. 2007, 3, 184.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXnt1GksLg%3D&md5=2c639a6e9abbfb3f3aaba6e8307f434cCAS |
[4] B. W. D’Andrade, S. R. Forrest, Adv. Mater. 2004, 16, 1585.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXpsFCntrw%3D&md5=1e3d9cc2f0b284aabdfc77f5a5587148CAS |
[5] A. C. Grimsdale, K. L. Chan, R. E. Martin, P. G. Jokisz, A. B. Holmes, Chem. Rev. 2009, 109, 897.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXit1emu7o%3D&md5=8902dc185d21ce8b798452c5e0462696CAS |
[6] S. H. Hwang, C. N. Moorefield, G. R. Newkome, Chem. Soc. Rev. 2008, 37, 2543.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXht1OksrnP&md5=01d08f6575862d2cf016be82c5d736b1CAS |
[7] J. Kido, Y. Okamoto, Chem. Rev. 2002, 102, 2357.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xjs1Snt70%3D&md5=ca7f07be039a20044834201d01ed6149CAS |
[8] Universal Display, www.universaldisplay.com (accessed 25 February 2011)
[9] Add-vision, Inc, www.add-vision.com (accessed 25 February 2011)
[10] Sumation Co Ltd, www.sumation.co.uk (accessed 25 February 2011)
[11] Printed Organic and Molecular Electronics 2004 (Eds D. R. Gamota, P. Brazis, K. Kalyansundaram, J. Zhang) (Kluwer Academic Publishers: Dordrecht).
[12] The OLED Handbook 2011 (Ed. R. Martens) (Metalgrass, OLED-Info: Herzelia).
[13] K. Müllen, U. Scherf, Organic Light-Emitting Devices: Synthesis, Properties, and Applications 2006 (Wiley-VCH: Weinheim).
[14] Z. Ma, P. Sonar, Z. K. Chen, Curr. Org. Chem. 2010, 14, 2034.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhsFartr7J&md5=32831cf16177f83d8074dd45a690ac56CAS |
[15] P. Sonar, M. S. Soh, Y. H. Cheng, J. T. Henssler, A. Sellinger, Org. Lett. 2010, 12, 3292.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXot1WntbY%3D&md5=82e63d7f68bf0d8ae8b16c52268785aaCAS |
[16] K. L. Chan, P. Sonar, A. Sellinger, J. Mater. Chem. 2009, 19, 9103.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhsFSgtrvJ&md5=d47d81a2332ab7216e17dc8f7d94a3dfCAS |
[17] M. Y. Lo, A. Sellinger, Synlett 2006, 18, 3009.
[18] M. Y. Lo, K. Ueno, H. Tanabe, A. Sellinger, Chem. Rec. 2006, 6, 157.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XntVChsLs%3D&md5=479f4c240b642006cee7877b505d9448CAS |
[19] M. Y. Lo, C. G. Zhen, M. Lauters, G. E. Jabbour, A. Sellinger, J. Am. Chem. Soc. 2007, 129, 5808.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXktFegs7c%3D&md5=a2516725210f84bf21063974a23c3ec7CAS |
[20] S. Sudhakar, A. Sellinger, Macromol. Rapid Commun. 2006, 27, 247.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XitlGks70%3D&md5=18dc2284bbb9937b7c163758134ce2d1CAS |
[21] H. Neureiter, W. Gebauer, C. Vaterlein, M. Sokolowski, P. Bauerle, E. Umbach, Synth. Met. 1994, 67, 173.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXisFKjtbk%3D&md5=735fe21241267cb5678b7a373e6ccbbeCAS |
[22] G. Horowitz, P. Delannoy, H. Bouchriha, F. Deloffre, J. L. Fave, F. Garnier, R. Hajlaoui, M. Heyman, F. Kouki, P. Valat, V. Wintgens, A. Yassar, Adv. Mater. 1994, 6, 752.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXotFaks7s%3D&md5=e90da99c6667f629820496018a3a3cc2CAS |
[23] J. S. Cho, Y. Kojima, K. Yamamoto, Polym. Adv. Technol. 2003, 14, 52.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXhtFKgsLY%3D&md5=80144ef953e73ee6f2d367336935205eCAS |
[24] C. Vaterlein, H. Neureiter, W. Gebauer, B. Ziegler, M. Sokolowski, P. Bauerle, E. Umbach, J. Appl. Phys. 1997, 82, 3003.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXmtVWktbY%3D&md5=d0be0547c40fb486004a722679216350CAS |
[25] M. Mazzeo, D. Pisignano, L. Favaretto, G. Barbarella, R. Cingolani, G. Gigli, Synth. Met. 2003, 139, 671.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXmvVKqs74%3D&md5=817ccf3f3e50c92987de72454e404efbCAS |
[26] J. M. Hancock, A. P. Gifford, R. D. Champion, S. A. Jenekhe, Macromolecules 2008, 41, 3588.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXlsVKmtL4%3D&md5=936979063ddc25877c5b0d094e9e3a66CAS |
[27] P. Sonar, S. P. Singh, S. Sudhakar, A. Dodabalapur, A. Sellinger, Chem. Mater. 2008, 20, 3184.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXkslChs78%3D&md5=c9c97968ce162cec65748005127d6b73CAS |
[28] P. Sonar, S. P. Singh, P. Leclère, M. Surin, R. Lazzaroni, T. T. Lin, A. Dodabalapur, A. Sellinger, J. Mater. Chem. 2009, 19, 3228.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXls1yrsbs%3D&md5=f89abea00e5aece43bc8374e5685c0ceCAS |
[29] H. E. Katz, L. Torsi, A. Dodabalapur, Chem. Mater. 1995, 7, 2235.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXpsVOmsbk%3D&md5=9446d518aa894754c5df9fb3cd1e3682CAS |
