Thursday, 23 April 2015, 15:00
Sala Grande Palazzina B via alla Cascata 56/C
Study of colloidal crystal thin films (progress report)
Vinča Institute of Nuclear Sciences, University of Belgrade,
Mike Petrovića Alasa 12-14, Belgrade, Serbia
Colloidal crystal thin films are prepared by spin-coating of a colloid of 300 nm polystyrene spheres on microscope glass substrates with or without a thin titanium dioxide layer on top. In searching for the optimal quality of crystals, several parameters are varied. The obtained samples were examined by optical, atomic force and scanning electron microscopy. Their optical properties are investigated by spectroscopic ellipsometry.
When we illuminate a self-assembled few-layer polystyrene colloidal crystal on the glass substrate, the light passes through it except at frequencies falling in the photonic band gap. On the other side, if a high-index titanium dioxide layer is deposited in-between the glass substrate and monolayer colloidal crystal film, it should act as a waveguide for the light due to total reflection. This study is a work in progress and I hope the interesting results will come in future.
Keywords: Glass photonics; Colloidal crystals; Opals; Light waveguide.