High-Performance Hybrid White Organic Light-Emitting Diodes Comprising Ultrathin Blue and Orange Emissive Layers

Two novel high-performance hybrid white organic light-emitting diodes have been realized by the delta-doping method. The device comprising a single ultrathin emissive layer exhibits a luminance of 46923 cd/m(2) and a low efficiency roll-off. To further simplify the device structures, another device comprising double ultrathin emissive layers achieves low driving voltages, a high color rendering index (75), and a high efficiency (8.9 lm/W). Moreover, it is found that these two devices not only exhibit fairly pure white emission but also show a rather stable color. Such superior properties reveal that the utilization of delta-doping technology provides a new way to achieve high-performance devices. (C) 2013 The Japan Society of Applied Physics