Dielectric Bragg Reflectors (DBR) are commercially manufactured onto rigid substrates, using inorganic materials (e.g. SiO2, TiO2). Recently, organic DBR are under investigation because they allow creation of tunable optical properties. During the wet fabrication processes, the choice of polymers that can be alternated is limited by the condition that the solvents of the alternating materials need to be orthogonal. Our goal is to deposit the organic DBR completely from the vapor phase by an innovative technique called initiated Chemical Vapor Deposition (iCVD). iCVD does not require the use of solvent and allows precise control over layer thickness by coupling with laser interferometry. The polymers that will be alternated will have a large refractive index contrast, as for example Teflon (n≈1.38) and polystyrene (n≈1.59), so to achieve high reflectivity with a limited number of layers. The surface roughness, interfacial roughness, the thickness and the electron densities of each layer will be characterized by X-ray reflectivity (XRR). The results will be compared with ellipsometry and microscopy data.
Compensation: 6 month / 440€ per month
Dr. Anna Maria Coclite, Assistant Professor
Dr. Roland Resel, Associate Professor