Abstract
We have investigated a method to enhance the light emission efficiency and color tuning for mixture of dyes with varying the growth parameters, during Alq3:Nile Red deposition. We used solvent bath and green laser (532 nm) for improvement of the performance of devices. This paper presents two kind of evaporation method, periodic and gradient. We observed that periodic emission layers can greatly improve the device performances such as electroluminescence, chromaticity coordinates, luminance, and reduced the turn on voltage. The periodic 3 structure with evaporation rate of (0.1 → 3 → 2 → 3 → 2 → 0.1 A°/s) has a luminance of 3000 cd/m2 and maximum efficiency of 1.8 cd/A at 18 V which are the highest values among devices.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abedi, Z., Janghouri, M., Mohajerani, E., Alahbakhshi, M., Azari, A., Fallahi, A.: Study of various evaporation rates of the mixture of Alq3: DCM in a single furnace crucible. J. Lumin. 147, 9–14 (2014)
Burrows, P.E., Forrest, S.R.: Electroluminescence from trap-limited current transport in vacuum deposited organic light emitting devices. Appl. Phys. Lett. 64, 2285–2287 (1994)
Chen, B.J., Lai, W.Y., Gao, Z.Q., Lee, C.S., Lee, S.T., Gambling, W.A.: Electron drift mobility and electroluminescent efficiency of tris (8-hydroxyquinolinolato) aluminum. Appl. Phys. Lett. 75, 4010–4012 (1999)
Cheng, L.F., Liao, L.S., Lai, W.Y., Sun, X.H., Wong, N.B., Lee, C.S., Lee, S.T.: Effect of deposition rate on the morphology, chemistry and electroluminescence of tris-(8-hydroxyqiunoline) aluminum films. Chem. Phys. Lett. 319, 418–422 (2000)
D’Andrade, B.W., Forrest, S.R.: White organic light-emitting devices for solid-state lighting. Adv. Mater. 16, 1585–1595 (2004)
Garbuzov, D.Z., Bulović, V., Burrows, P.E., Forrest, S.R.: Photoluminescence efficiency and absorption of aluminum-tris-quinolate (Alq3) thin films. Chem. Phys. Lett. 249, 433–437 (1996)
Janghouri, M., Mohajerani, E., Khabazi, A., Abedi, Z., Razavi, H.: Effect of doping different dyes in Alq3 on electroluminescence and morphology of layers using single furnace method. J. Lumin. 140, 7–13 (2013)
Janghouri, M., Mohajerani, E., Amini, M.M., Najafi, E.: Red organic light emitting device based on TPP and a new host material. Appl. Phys. A 114, 445–451 (2014)
Kafafi, Z.H.: Organic Electroluminescence. CRC Press, Boca Raton (2005)
Kido, J., Kimura, M., Nagai, K.: Multilayer white light-emitting organic electroluminescent device. Science 267, 1332–1334 (1995)
Lax, M.: Cascade capture of electrons in solids. Phys. Rev. 119, 1502–1523 (1960)
Lee, C.B., Uddin, A., Hu, X., Anderssonb, T.G.: Study of Alq3 thermal evaporation rate effects on the OLED. Mater. Sci. Eng. B 112, 14–18 (2004)
Lin, H.P., Zhou, F., Li, J., Zhang, X.W., Yu, D.B., Zhang, L., Zhang, Z.L.: A high performance of BPhen-based white organic light-emitting devices with a dual-emitting layer and its electroluminescent spectral property. J. Ind. Eng. Chem. 17, 675–680 (2011)
Liu, J., Shao, S.Y., Chen, L., Xie, Z.Y., Cheng, Y.X., Geng, Y.H., Wang, L.X., Jing, X.B., Wang, F.S.: White electroluminescence from a single polymer system: improved performance by means of enhanced efficiency and red-shifted luminescence of the blue-light-emitting species. Adv. Mater. 19, 1859–1863 (2007)
Mahmoudi, M., Janghouri, M., Mohajerani, E.: Easily controlled dye doped phosphorescent OLEDs with evaporation rate in single furnace. J. Lumin. 160, 210–215 (2015)
Morris, R., Silver, M.: Direct electron–hole recombination in anthracene. J. Chem. Phys. 50, 2969–2973 (1969)
Onsager, L.: Deviations from Ohm’s law in weak electrolytes. J. Chem. Phys. 2, 599–615 (1934)
Song, H.J., Lee, J.Y., Song, I.S., Moon, D.K., Haw, J.R.: Synthesis and electroluminescence properties of fluorene–anthracene based copolymers for blue and white emitting diodes. J. Ind. Eng. Chem. 17, 352–357 (2011)
Sun, Y., Giebink, N.C., Kanno, H., Ma, B., Thompson, M.E., Forrest, S.R.: Management of singlet and triplet excitons for efficient white organic light-emitting devices. Nature 440, 908 (2006)
Szmytkowski, J., Stampor, W., Kalinowski, J., Kafafi, Z.H.: Electric field-assisted dissociation of singlet excitons in tris-(8-hydroxyquinolinato) aluminum (III). Appl. Phys. Lett. 80, 1465–1467 (2002)
Yook, K.S., Lee, J.Y.: Effect of the interlayer composition on the lifetime and color change of hybrid white organic light-emitting diodes. J. Ind. Eng. Chem. 17, 642–644 (2011)
Zhang, F., Xu, Z., Zhao, D., Zhao, S., Jiang, W., Yuan, G., Xu, X.: Influence of evaporation conditions of Alq3 on the performance of organic light emitting diodes. J. Phys. D Appl. Phys. 40, 4485 (2007)
Acknowledgements
The author would like to thank the Urmia University of Technology and Shahid Beheshti University for supporting this work.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Janghouri, M., Mohajerani, E. Color optimization of red OLEDs via periodic and gradient deposition rate of fluorescent dopants. Opt Quant Electron 51, 282 (2019). https://doi.org/10.1007/s11082-019-2001-y
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s11082-019-2001-y