We report on improved and controlled light outcoupling of transparent organic light-emitting diodes (TOLEDs) by inserting thin silver layers between the indium tin oxide anode and the hole transporting layer. The introduction of Ag layers influences both the bottom and top emission of the TOLEDs, and it results in dramatic changes in the electroluminescence spectra and angular distribution. We find that the overall external quantum efficiency can be increased up to 18.8%, and the ratio of bottom and top emission can be almost identical.
© 2011 Optical Society of America
Original Manuscript: June 15, 2011
Revised Manuscript: July 4, 2011
Manuscript Accepted: July 7, 2011
Published: August 1, 2011
Jonghee Lee, Simone Hofmann, Michael Thomschke, Mauro Furno, Yong Hyun Kim, Björn Lüssem, and Karl Leo, "Increased and balanced light emission of transparent organic light-emitting diodes by enhanced microcavity effects," Opt. Lett. 36, 2931-2933 (2011)