타이타늄 산화물 박막층을 도입한 고분자 발광 다이오드의 특성 연구

Abstract

Polymer light-emitting diodes (PLEDs) continue to draw considerable attention as next generation displays because of their many advantages, such as low power consumption, easy fabrication,full-color emission, and flexibility. Although encouraging progress has been made in device performance over the last few years, it still does not satisfy realistic specifications for commercialization. One serious problem is the difficulty of electron injection in current PLED devices with an anode/polymer/cathode geometry. This is particularly true for the case of an Al electrode. The work function of Al is too high to match the lowest unoccupied molecular orbit (LUMO), level of luminescent polymers, thereby lowering the device efficiency. In this work, we show that introducing a solution-based titanium-oxide (TiOx) thin film as an electron injection layer between the polymer and the Al electrode, enhances the device efficiency. The TiOx layer reduces the barrier height between the polymer and the Al cathode, thereby facilitating electron injection in the devices.