Optimal Structure of Color-Conversion Layer for White Organic Light-Emitting Diode on Silver-Nanowire Anode

Abstract

We fabricated fluorescent blue organic light-emitting diodes (OLEDs) using a silver-nanowire (AgNW) anode on a polyethylene terephthalate substrate. Flexible white OLEDs with high color rendering index (CRI) were successfully obtained through color conversion of the blue OLEDs. Using a single layer of color converting phosphor particles, we showed that the variation of CRI with viewing angle depended on the path length of light through the color conversion layer (CCL). We proposed a method to obtain an optimal number of CCL to maximize the CRI value of down-conversion white OLEDs. The color conversion from blue to white using CCLs was compared for the OLEDs on AgNW and conventional indium-tin oxide (ITO) anodes. Due to the light scattering effect of AgNW, the OLED on AgNW electrode showed higher device efficiencies and lower CRI dependence on viewing angle than that on ITO anode.