Investigation of MEH-PPV OLED Assisted by An IoT Environment Monitoring System
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Abstract
Single layer organic light emitting diode (OLED) devices based on poly{[2-methoxy-5-(-2ethylhexyloxy)-1,4-phenylene]vinylene} (MEH-PPV) are fabricated and studied in this work. There are several factors that affect the performance of the fabricated OLED samples. Some of these factors are related to the fabrication parameters chosen for the OLED fabrication process. The effect of concentration and annealing temperature are investigated. Other environmental factors such as humidity or temperature affect the performance of fabricated OLED samples under long term exposure. An internet of things environment monitoring system (IoT-EMS) is developed to monitor and study the effect of these factors on the performance of the OLED samples. Exposure to humidity is found to severely degrade the samples. In summary, the optimum concentration for MEH-PPV is concluded to be 4 mg/ml, and the best annealing temperature is 90°C in this study. It is also deduced that humidity of 72-75 % caused degradation of the samples in less than 20 hours.
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References
S. M. Lee, J. H. Kwon, S. Kwon and K. C. Choi, “A Review of Flexible OLEDs Toward Highly Durable Unusual Displays,” IEEE Trans. Electron Devices, vol. 64, no. 5, pp. 1922–1931, 2017. doi:10.1109/TED.2017.2647964.
D. D. C. Bradley, A. R. Brown, P. L. Burn, R. H. Friend, A. B. Holmes and A. Kraft, “Light-Emitting Diodes Based on Conjugated Polymers: Control of Colour and Efficiency,” Nature, vol. 347, pp. 539, 1990.
R. H. Friend, R. W. Gymer, A. B. Holmes, J. H. Burroughes, R. N. Marks, C. Taliani, D. D. C. Bradley, D. A. Dos Santos, J. L. Breda, et al., “Electroluminescence in Conjugated Polymers,” Nature, vol. 397, pp. 121–128, 1999. doi:10.1038/16393.
C. Liedenbaum, Y. Croonen, P. van de Weijer, J. Vleggaar and H. Schoo, “Low Voltage Operation of Large Area Polymer LEDs,” Synth. Met., vol. 91, no. 1–3, pp. 109–111, 1997. doi:10.1021/bm800026t.
C. C. Hsiao, C. H. Chang, T. H. Jen, M. C. Hung and S. A. Chen, “High-efficiency Polymer Light-emitting Diodes based on poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene] with Plasma-polymerized CHF3-modified Indium Tin Oxide as An Anode,” Appl. Phys. Lett., vol. 88, no. 3, pp. 1–3, 2006. doi:10.1063/1.2165192.
D. Kajiya, T. Koganezawa and K. I. Saitow, “Hole Mobility Enhancement of MEH-PPV Film by Heat Treatment at Tg,” AIP Adv., vol. 5, no. 12, 2015. doi:10.1063/1.4939135.
T. W. Lee and O. O. Park, “Effect of Different Heat Treatments on the Luminescence Efficiency of Polymer Light-emitting Diodes,” Adv. Mater., vol. 12, no. 11, pp. 801–804, 2000. doi:10.1002/(SICI)1521-4095(200006)12.
J Liu, T. F. Guo and Y. Yang, “Effects of Thermal Annealing on the Performance of Polymer Light Emitting Diodes,” J. Appl. Phys., vol. 91, no. 3, pp. 1595–1600, 2002. doi:10.1063/1.1427435.
S. Scholz, D. Kondakov, B. Lüssem and K. Leo, “Degradation Mechanisms and Reactions in Organic Light-emitting Devices,” Chem. Rev., vol. 115, no. 16, pp. 8449–8503, 2015. doi:10.1021/cr400704v.
D. Zou, M. Yahiro and T. Tsutsui, “Study on the Degradation Mechanism of Organic Light-emitting Diodes (OLEDs),” Synth. Met., vol. 91, no. 1, pp. 191–193, 1997. doi:https://doi.org/10.1016/S0379-6779(97)04012-5.