New Polyurethanes Containing Carbazole as Hole-Transport Material and Phosphorescent Host for Organic/Polymer Light Emitting Diodes

摘要

Polyurethanes (PUs) have been widely used in industrial applications due to their good properties in good elasticity, flexibility, thermal stability, and excellent chemical resistance. Recently, application of PUs on PLED has been reported. Since PUs were usually prepared from condensation polymerization of diols and diisocyanates under metal-ion free conditions, metal-ion contaminants could therefore be minimized. In addition, the adhesion of polar PU on ITO surface is expected to be good. This may benefit for the PLED device fabrication.Carbazole (Cz) derivatives are photoconductors with good hole-transport properties. Recently, carbazole derivatives have been used as efficient triplet hosts in phosphorescent OLED. All these intrigued us to explore the application potentials of carbazole containing PUs on PLED applications. 2,5-Diphenyl-1,3,4-oxadiazole (OXD) and its derivatives are common electron injection and transport materials due to their prominent electron affinity, high photoluminescence, and good thermal stability. Since doping of the electron-deficient components into the hole-transport layer sometimes may improve the performance of the OLED device,we are interested in studying the performance of Cz-OXD copolymers on PLED.