The optical constants of emitter and electrode materials in polymer light-emitting diodes

The optical constants of spun-cast films of several polyfluorene derivatives were examined using a combination of reflection and transmission spectroscopic ellipsometry. Results for both unannealed films and films annealed at 150 deg. C are presented. For some polymers, annealing allowed the polymer chains to re-organize such that the films became more isotropic. The optical constants of two common metal cathodes, calcium and aluminium, were investigated using reverse ellipsometry. Multi-layer structures incorporating both polymer and metal layers were also successfully modelled. (rapid communication)