13 September 2012 Boosting the performance of red PHOLEDs by exciton harvesting
Author Affiliations +
Significant development has been made on phosphorescent organic light emitting diodes (PHOLEDs) over the past decade, which eventually resulted in the commercialization of widely distributed active-matrix organic light emitting diode displays for mobile phones. However, higher efficiency PHOLEDs are still needed to further reduce the cost and lower the power consumption for general lighting and LED backlight applications. In particular, red PHOLEDs currently have in general the lowest efficiencies among the three primary colors, due most likely to the energy-gap law. Therefore, a number of groups have of made use of various device configurations, including insertion of a carrier blocking or exciton confining layer, doping the transport layers, as well as employing multiple emissive zone structures to improve the device efficiency. However, these approaches are rather inconvenient for commercial applications. In this work, we have developed a simpler way to boost the performance of red PHOLEDs by incorporating an exciton harvesting green emitter, which transfers a large portion of the energy to the co-deposited red emitter. A high external quantum efficiency (EQE) of 20.6% was achieved, which is among the best performances for red PHOLEDs.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Y.-L. Chang, Y.-L. Chang, Z. B. Wang, Z. B. Wang, M. G. Helander, M. G. Helander, J. Qiu, J. Qiu, Z. H. Lu, Z. H. Lu, } "Boosting the performance of red PHOLEDs by exciton harvesting", Proc. SPIE 8476, Organic Light Emitting Materials and Devices XVI, 84761Q (13 September 2012); doi: 10.1117/12.930224; https://doi.org/10.1117/12.930224

Back to Top