Enhanced coupling of light from organic light emitting diodes using nanoporous films

We have demonstrated an approach to enhance the light extraction efficiency for organic light emitting diode (OLED). Nanoporous alumina film was used to modify the optical wave propagation and coupling of light from the OLED. Experimental results showed an increase of over 50% in the coupling efficiency of the nanoporous device, without affecting the electrical properties of the OLED. Effective medium theory can be used to model the optical properties of the nanoporous media and simulated the optical characteristics of the OLED successfully. (C) 2004 American Institute of Physics.