| 초록 |
Light-emitting diodes (LEDs) based on low molecular weight organics or polymer materials have attracted extensive attention due to their promising advantages of high contrast ratio, long lifetime, and low power consumption. In order to realize LEDs with 100% external quantum efficiency, defined as the ratio of the number of emitted photons into air to the number of injected electrons, several strategies have been introduced to overcome waveguide problem and extract more light from the device. In particular, many research groups have shown strong interest in effective way of using two-dimensional (2D) photonic crystal (PhC) patterns. Here, we propose a 2D TiO2 honeycomb structure fabricated by a sol-gel process from a 2D colloidal crystal film and demonstrate its use as a 2D PhC to extract waveguided light from polymer LEDs. By applying the 2D TiO2 honeycomb structure on the backside of the glass, the light extraction efficiency of a polymer LED was improved by a factor of 1.44. |
