Transmission electron microscopy study of the indium/P3OT and aluminium/P3OT interfaces (P3OT is poly (3-octylthiophene))

In this article the morphological stability of interfaces between two different metals and a conjugated semiconducting polymer is studied. Indium and aluminium are deposited on top of a poly(3-octylthiophene) (P3OT) layer. The diffusion behaviour of the metals is investigated as a function of temperature and annealing time in order to mimic the situation in an operating polymer light-emitting diode (LED) device. Indium is shown to diffuse into the P3OT layer at high temperatures, while aluminium seems to form a rather stable interface with P3OT.