Fraunhofer Institute for Applied Optics and Precision Engineering IOF
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.
References
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