Quantum well/columnar discotic hybrids

Theory predicts that the deposition of a nanostructured dielectric film on the surface of a semiconductor quantum well will modulate its optical properties due to interactions between the quantum well exciton and the dielectric structure. We have chosen a columnar discotic triphenylene as dielectric medium since the columnar structure is able to provide spatial, and thus dielectric, modulations both on a 2 or a 0.4 nm scale, depending on the columnar orientation within the film. Film deposition on quantum well structures and model substrates by spincoating and via the vapour phase, in combination with annealing steps, gave rise to a rich spectrum of textural modifications and columnar orientations in the dielectric films. The investigations revealed significant modulations of the optical properties of the quantum well as a function of the textures and the columnar orientational order.