Monte Carlo analysis of the spectral photon emission and extraction efficiency of organic light-emitting devices

We report on a Monte Carlo method for modeling light transport phenomena in multilayer organic polymer light-emitting devices on plastic flexible substrates. The method allows modeling of Cartesian geometrical structures describing the fate of photons through multiple scattering events determined by the wavelength-dependent material optical properties. We apply the method to analyze the wavelength distribution of emitted light spectra. We find that for all organic polymers considered, the light emission is slightly shifted toward the longer wavelengths, and that this shift is maximum for light emissions with peaks around 530 nm. The photon extraction efficiency is higher (0.430) for organic polymers emitting in the longer wavelengths, while the photon absorbed fraction is higher (0.676) for spectra with a maximum in the short wavelengths. (C) 2001 American Institute of Physics.