Efficiency enhancement of organic based Light Emitting Diodes using a   scattering layer
  This paper presents an investigation of organic LED extraction efficiency enhancement using a low refractive index scattering layer. A scattering model is developed based on rigorous electromagnetic modelling techniques. The model accounts for proportions of scattered guided and radiation modes as well as the efficiencies with which emitted and scattered light are extracted. Constrained optimisation techniques are implemeneted for a single operation wavelength to maximise the extraction efficiency of a generic OLED device. Calculations show that a 2 fold efficiency enhancement is achievable with a correctly engineered scattering layer. The detailed analysis of the enhancement mechanism highlights ways in which this scheme could be improved. 
R. F. Oulton, C. S. Adjiman, K. Handa and S. Aramaki