P‐180: Highly‐Efficient Tandem White Organic Light Emitting Devices

Abstract We demonstrate efficient tandem p‐i‐n White Organic Light Emitting Diodes (WOLEDs) with the transparent NPB:WO 3 interconnecting layer. The CIE x,y coordinate, luminance yield and E.Q.E of the tandem OLEDs (at 20 mA/cm 2 ) are (0.30, 0.43), 23.9 cd/A and 8.5%, respectively. The CIE x,y coordinates of the tandem OLEDs neither change (Δx,y < 0.02) with driving current nor with forward viewing angle (±60 degree). This performance of tandem WOLEDs represents considerable improvement over what have been known in the literature.