L. Skowronski

Novel GIMS technique for deposition of colored Ti/TiO₂ coatings on industrial scale

Abstract The aim of the present paper has been to verify the effectiveness and usefulness of a novel deposition process named GIMS (Gas Injection Magnetron Sputtering) used for the flrst time for deposition of Ti/TiO₂ coatings on large area glass Substrates covered in the condition of industrial scale production. The Ti/TiO₂ coatings were deposited in an industrial System utilizing a set of linear magnetrons with the length of 2400 mm each for covering the 2000 × 3000 mm glasses. Taking into account the speciflc course of the GIMS (multipoint gas injection along the magnetron length) and the scale of the industrial facility, the optical coating uniformity was the most important goal to check. The experiments on Ti/TiO₂ coatings deposited by the use of GIMS were conducted on Substrates in the form of glass plates located at the key points along the magnetrons and intentionally non-heated during any stage of the process. Measurements of the coatings properties showed that the thickness and optical uniformity of the 150 nm thick coatings deposited by GIMS in the industrial facility (the thickness differences on the large plates with 2000 mm width did not exceed 20 nm) is fully acceptable form the point of view of expected applications e.g. for architectural glazing.

Optical properties of disperse dyes doped poly(methyl methacrylate)

ABSTRACT In this paper, we investigated Disperse Red (DR1, DR13) and Disperse Orange (DO3, DO13) dyes embedded into poly(methyl methacrylate) (PMMA) polymeric matrix. The linear optical properties such as absorption coefficient, refractive index and energy band-gap of guest-host polymeric thin films were studied using spectroscopy and spectroscopic ellipsometry combined with transmittance measurements.  We found that the refractive index of DR1 is higher than the refractive indices for other studied azo dyes compounds. We also observed that the energy band-gap of studied materials varies from about 2 eV to 2.3 eV.

Growth model and structure evolution of Ag layers deposited on Ge films

We investigated the crystallinity and optical parameters of silver layers of 10–35 nm thickness as a function 2–10 nm thick Ge wetting films deposited on SiO2 substrates. X-ray reflectometry (XRR) and X-ray diffraction (XRD) measurements proved that segregation of germanium into the surface of the silver film is a result of the gradient growth of silver crystals. The free energy of Ge atoms is reduced by their migration from boundaries of larger grains at the Ag/SiO2 interface to boundaries of smaller grains near the Ag surface. Annealing at different temperatures and various durations allowed for a controlled distribution of crystal dimensions, thus influencing the segregation rate. Furthermore, using ellipsometric and optical transmission measurements we determined the time-dependent evolution of the film structure. If stored under ambient conditions for the first week after deposition, the changes in the transmission spectra are smaller than the measurement accuracy. Over the course of the following three weeks, the segregation-induced effects result in considerably modified transmission spectra. Two months after deposition, the slope of the silver layer density profile derived from the XRR spectra was found to be inverted due to the completed segregation process, and the optical transmission spectra increased uniformly due to the roughened surfaces, corrosion of silver and ongoing recrystallization. The Raman spectra of the Ge wetted Ag films were measured immediately after deposition and ten days later and demonstrated that the Ge atoms at the Ag grain boundaries form clusters of a few atoms where the Ge–Ge bonds are still present.