Conjugated organic semiconductors form an exciting class of materials that can be used in a variety of cutting edge technologies including organic light-emitting diodes (OLEDs), solar cells and transistors. In order to optimise the materials and devices it is critical to understand the structure-property relationships for the organic semiconductors by relating the ¿molecular¿ structure to the film morphology and correlating these to the photophysical and device characteristics. Mixed organic films used in the emissive layer of OLEDs have shown layering behaviour, and in this work we propose to use neutron reflectometry to investigate layering in co-evaporated films of doped emissive films.