Towards Greatly Improved Efficiency of Polymer LED

Polymer light-emitting diodes (PLEDs) show great promise of revolutionizing display technologies. The archetypical multilayer PLED heterostructure introduces numerous chemical and physical challenges to the develoment of efficient and robust devices. These layered structure are formed from solution based spin-casting or printing with subsequesnt removal of the solvent. However, solvent from the freshly deposited film may dissolve or partially dissolve the underlying layer resulting in loss of the desired structure and corresponding device functionality. Undesirable changes in the morphology and interfaces of the polymer films are another detrimental effect associated with solvent removal. Herein, we demonstrated that by embedding hole transporting materials (HTLs) in a cross-linked polymer matrix, the total luminance and external quantum efficiency were greatly improved over devices without this HTL layer.