Using Interlayer Step-Wise Triplet Transfer to Achieve an Efficient White Organic Light-Emitting Diode with High Color-Stability


An efficient phosphorescent white organic light emitting-diode with a red-green-blue 3tri-emitting-layer structure is reported. The host of the red dopant possesses a lower triplet-energy than the green dye. An interlayer step-wise triplet transfer via blue dye -> green dye -> red host -> red dye is achieved. This mechanism allows an efficient triplet harvesting by the three dopants, thus maintaining a balanced white light and reducing energy loss. Moreover, the color stability of the device is improved significantly. The white device not only achieves a peak external quantum efficiency of 21.1 +/- 0.8% and power efficiency of 37.5 +/- 1.4 lm/W but shows no color shift over a wide range of voltages.



Ir(ppy)3, White organic light-emitting diode, Triplet state, Color

"The authors acknowledge the National Natural Science Foundation of China (No. 51333007), the Foundation of Jilin Research Council (Nos. 2012ZDGG001, 20130206003GX, and 201105028), CAS Instrument Project (No. YZ201103), China Postdoctoral Science Foundation (No. 20130201120048), and United States' NSF CAREER (No. ECCS-0950731) for the support of this research."


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Wang, Qi, Dongge Ma, Karl Leo, Junqiao Ding, et al. 2014. "Using interlayer step-wise triplet transfer to achieve an efficient white organic light-emitting diode with high color-stability." Applied Physics Letters 104(19): 193303-1 to 4.