Optical EngineeringUsing holography to increase the light output efficiency of an organic light-emitting diode—angular, wavelength, and near-field effects
|Format||Member Price||Non-Member Price|
The authors propose the use of holograms to modify both sides of the substrate of an organic light-emitting diode (OLED) to increase its light output efficiency and to discuss the associated angular, spectral, and near-field effects. A single-source macroscopic phase hologram experiment is used to illustrate the idea. Since the emitted light originates from dynamically varying positions with different directions and has wavelengths longer than the nanometer layer thickness of an OLED, the angular, wavelength, and near-field effects have been analyzed. Diffraction efficiency due to the dynamic density and position variations of the excitons has been discussed. The subwavelength near-field wave propagation effect is described with finite-difference time domain solutions to Maxwell's equations. These effects are not limited to the holographic method, but should exist in other substrate-modification methods proposed for increasing the OLED's external light efficiency.