摘要
Organic light-emitting diodes(OLEDs)have gained considerable attention because of their use of inherently flexible materials and their compatibility with facile roll-to-roll and printing processes.In addition to high efficiency,flexibility and transparency,reliable color tunability of solid state light sources is a desirable feature in the lighting and display industry.Here,we demonstrate a device concept for highly efficient organic light-emitting devices whose emission color can be easily adjusted from deep-blue through cold-white and warm-white to saturated yellow.Our approach exploits the different polarities of the positive and negative half-cycles of an alternating current(AC)driving signal to independently address a fluorescent blue emission unit and a phosphorescent yellow emission unit which are vertically stacked on top of each other.The electrode design is optimized for simple fabrication and driving and allows for two-terminal operation by a single source.The presented concept for color-tunable OLEDs is compatible with application requirements and versatile in terms of emitter combinations.
基金
This work was funded by the European Social Fund and the Free State of Saxony through the OrthoPhoto project
We kindly acknowledge the support from NUDEV.
