Enhanced coupling of light from OLED based on nanoporous substrates

We have demonstrated a new approach to enhance the light extraction efficiency for organic light emitting diode (OLED). Self-aligned, nanoporous alumina film was used as a quasi-2D photonic crystal to modify the optical wave propagation and coupling of light from the OLED. Waveguiding modes are turned into leaky modes. The experimental results showed an increase of over 50% in the coupling efficiency of the nanoporous device, without affecting the electrical properties of the OLED. We used the effective medium theory to model the optical properties of the nanoporous media and simulated the optical characteristics of the devices.