42517 2017 eng 487 493 Part B 421 article Elsevier B.V. 1 -- -- -- The practical performance of surface coatings in applications like catalysis, water splitting or batteries depends critically on the coating materials’ porosity. Determining the porosity in a fast and nondestructive way is still an unsolved problem for industrial thin-films technology. As a contribution to calibrated, non-destructive, optical layer characterisation, we present a multi-method comparison study on porous TiO2 films deposited by sol-gel synthesis on Si wafers. The ellipsometric data were collected on a range of samples with different TiO2 layer thickness and different porosity values. These samples were produced by templated sol-gel synthesis resulting in layers with a well-defined pore size and pore density. The ellipsometry measurement data were analysed by means of a Bruggeman effective medium approximation (BEMA), with the aim to determine the mixture ratio of void and matrix material by a multi-sample analysis strategy. This analysis yielded porosities and layer thicknesses for all samples as well as the dielectric function for the matrix material. Following the idea of multi-method techniques in metrology, the data was referenced to imaging by electron microscopy (SEM) and to a new EPMA (electron probe microanalysis) porosity approach for thin film analysis. This work might lead to a better metrological understanding of optical porosimetry and also to better-qualified characterisation methods for nano-porous layer systems. 1. IntroductionPorous materials, especially porous thin films play an importantrole in chemical and physical technology in every case where thecontact area between two media has to be maximised. From cataly-sis to photochemistry and photovoltaics, the applications of porouslayer materials are diverse and numerous [1–6].The accurate and non-destructive characterisation of porousfilms for layered systems poses a challenge. This applies especiallyfor the key parameter of porous films, their porosity, i.e. the mix-ing ratio between the Matrix of the film (host material) and thepore volume which is empty or filled with a fluid medium (inclu-sions). This parameter influences most of the physical and chemicalproperties of a porous thin film and is therefore essential for theunderstanding as well as the optimisation of this class of materials. Applied Surface Science 10.1016/j.apsusc.2016.11.055 0169-4332 1873-5584 International Conference on Spectroscopic Ellipsometry (ICSE-7) Berlin, Germany 06.06.2016 10.06.2016 16.10.2017 Dana-Maria Rosu Erik Ortel Vasile-Dan Hodoroaba R. Kraehnert Andreas Hertwig eng uncontrolled Spectroscopic ellipsometry eng uncontrolled Porous materials eng uncontrolled Porosimetry eng uncontrolled Multi-sample analysis eng uncontrolled Thin film metrology Analytische Chemie Ingenieurwissenschaften und zugeordnete Tätigkeiten Verlagsliteratur Datei im Netzwerk der BAM verfügbar ("Closed Access")