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

Autor: Paul L. Burn, Mujeeb Ullah, Soniya D. Yambem, Ebinazar B. Namdas, Kristen Tandy
Rok vydání: 2013
Předmět:
Zdroj: Laser & Photonics Reviews. 8:165-171
ISSN: 1863-8880
DOI: 10.1002/lpor.201300148
Popis: 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.
Databáze: OpenAIRE