A simple method for the photometric characterization of organic light-emitting diodes

•A large area photodiode in contact with the OLED surface capture 82% of the total emitted power.•The total emitted power is calculated from OLED Lambertian emission space pattern with the photodiode placed on axis at a distance from the OLED surface.•The distance must be chosen so as the photodiode sees the OLED as a point source.•The method can be extended to non-Lambertian LED sources by measuring in advance the spatial emission pattern.•External quantum efficiency is calculated from OLED electroluminescence spectrum and the equivalent responsivity of the photodiode.•Photometric quantities are derived from the radiometric counterparts.