Defect profiling in organic semiconductor multilayers

► Defect depth profile studies are carried out in organic semiconductor (OSC) heterostructures using positron accelerator. ► Defects are seen to be present at the organic-organic and organic-substrate interfaces. ► The nature and type of defects in p-p bilayer are seen to be different from p-n and n-p-n multilayers. ► Defects influence positron systematics more than intrinsic electric field at the organic-organic interfaces. ► Positron mobility in OSC layers is seen to be comparable to the effective mobility of charge carriers.