1 - Transparent, white OLED (OSRAM Opto Semiconductors). 2 - Measured and simulated mission pattern of a blue OLED. 3 - Thickness dependent efficiencies of a blue emitting OLED series.

Optical characterization and optimization of OLEDs

Optics of organic LEDs

The quantitative optical description and general technical optimization of the upcoming, commercial light source organic LED require a profound knowledge of the active & passive optical properties of the system „OLED“.


Optical Characterization

  • Model free determination of thin film material dispersions n(λ)+ik(λ)
  • Measurement of layer thicknesses inside final OLED stacks
  • Measurement of polarized, angular & spectrally resolved emission pattern in air and substrate glass, respectively
  • Detailed optical modelling using in-house software („Radiating Slabs“)
  • Conclusion to properties of electrically pumped OLED emitting material


Emitter Properties

OLEDs comprising an adapted thin film stack (e.g. emitter – cathode – distance) enable to determine

  • internal electroluminescence spectrum,
  • emitter orientation distribution,
  • profile of the emission zone, and
  • quantum efficiency of excited state luminescence

by far-field radiation pattern measurement in conventional, electrically pumped operation and subsequent optical analysis.



M. Flämmich, N. Danz et al. in:

  • Appl. Opt. 48 (2009) 1507
  • Appl. Phys. Lett. 95 (2009) 263306
  • Org. Electron. 11 (2010) 1039

M.C. Gather, N. Danz et al. in:

  • Appl. Phys. Lett. 94 (2009) 263301