ITO-free top emitting organic light emitting diodes with enhanced light out-coupling

Yambem, Soniya D.; Ullah, Mujeeb; Tandy, Kristen; Burn, Paul L.; Namdas, Ebinazar B.

Abstract

Bottom emitting organic light emitting diodes (OLEDs) can suffer from lower external quantum efficiencies (EQE) due to inefficient out-coupling of the generated light. Herein, it is demonstrated that the current efficiency and EQE of red, yellow, and blue fluorescent single layer polymer OLEDs is significantly enhanced when a MoOx(5 nm)/Ag(10 nm)/MoOx(40 nm) stack is used as the transparent anode in a top emitting OLED structure. A maximum current efficiency and EQE of 21.2 cd/A and 6.7%, respectively, was achieved for a yellow OLED, while a blue OLED achieved a maximum of 16.5 cd/A and 10.1%, respectively. The increase in light out-coupling from the top-emitting OLEDs led to increase in efficiency by a factor of up to 2.2 relative to the optimised bottom emitting devices, which is the best out-coupling reported using solution processed polymers in a simple architecture and a significant step forward for their use in large area lighting and displays.

Citation

Yambem, S. D., Ullah, M., Tandy, K., Burn, P. L., & Namdas, E. B. (2014). ITO-free top emitting organic light emitting diodes with enhanced light out-coupling. Laser and Photonics Reviews, 8(1), 165-171. https://doi.org/10.1002/lpor.201300148

• Journal Article Type: Article
• Online Publication Date: Nov 6, 2013
• Publication Date: 2014-01
• Deposit Date: Apr 13, 2017
• Journal: Laser & Photonics Reviews
• Print ISSN: 1863-8880
• Electronic ISSN: 1863-8899
• Publisher: Wiley-VCH Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Issue: 1
• Pages: 165-171
• DOI: https://doi.org/10.1002/lpor.201300148
• Public URL: https://durham-repository.worktribe.com/output/1359803