Controlled light emission from white organic light-emitting devices with a single blue-emitting host and multiple fluorescent dopants

다국어 초록 (Multilingual Abstract)

<P>In this work, we fabricated white organic light-emitting devices (WOLEDs) containing a layered light-emitting region composed of a single blue-emitting host and different fluorescent dopant materials. The effects of varying the dye-doping ratio and emitting layer thickness on the efficiency, lifetime, spectral voltage-dependence and white balance were investigated for devices with a blue/orange stacked layer structure. Addition of a blue host layer doped with a green-emitting dopant, to give a blue/green/orange emitter, resulted in a broadband white spectrum without the need for a charge-blocking interlayer. The composition of blue, green and orange dopants in the host and the thickness of each emitting layer were optimized, resulting in a device efficiency of 9–11 cd A<SUP>−1</SUP> even at a high brightness of 10 000 cd m<SUP>−2</SUP> (achieved at a bias voltage of less than 9 V) with an emission spectrum suitable for lighting applications.</P>