An OLED may include regions of a mineral having a refractive index less than that of the substrate, allowing for emitted light in a waveguide mode to be extracted into air. These regions can be placed adjacent to the emissive regions of an OLED in a direction parallel to the electrodes. The substrate may also be given a nonstandard shape to further improve the conversion of waveguide mode and/or glass mode light to air mode. The outcoupling efficiency of such a device may be up to two to three times the efficiency of a standard OLED.
 This invention was made with U.S. Government support under Contract No. DE-FG02-04ER84113 awarded by the Department of Energy. The government has certain rights in this invention.