We have developed an angular luminescence spectrometer that determines the position and orientation of emitters inside a working OLED stack or a single emitter film by measuring the electroluminescence (EL) or photoluminescence (PL) spectrum in all emission- and polarization angles. The angular spectrum and polarization is a fingerprint of the emitter molecules’ orientation and of the position inside the emitting layer. In this presentation we will review various aspects of angular EL and PL spectroscopy and the data analysis by optical modeling on the basis of selected measurements., Presenter: Balthasar Blülle