title: Influence of organic capping layers on the performance of transparent organic light-emitting diodes.
abstract: We investigate a set of transparent organic LEDs (TOLEDs) with different organic capping layer (OC) thicknesses to understand the capping layer effect. We find that thickness variation of the OC strongly influences the emission properties of TOLEDs and exhibits different trends for top or bottom emission. The external quantum efficiency for the top side can be enhanced by a factor of 63%, but that of the bottom side only by 4% compared to a reference device without an OC. Additionally, we demonstrate that the introduction of the OC is an effective method to control the bottom-to-top emission ratio within a measured range from 2.87 to 6.05.
authors.affiliation: Institut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden, Germany. jonghee.lee@iapp.de
authors.forename: Jonghee
authors.initials: J
authors.lastname: Lee
authors.forename: Simone
authors.initials: S
authors.lastname: Hofmann
authors.forename: Mauro
authors.initials: M
authors.lastname: Furno
authors.forename: Michael
authors.initials: M
authors.lastname: Thomschke
authors.forename: Yong Hyun
authors.initials: YH
authors.lastname: Kim
authors.forename: Björn
authors.initials: B
authors.lastname: Lüssem
authors.forename: Karl
authors.initials: K
authors.lastname: Leo