## 2 Materials and Methods  
### Synthesis and Characterization of Films  
Magnetron sputtering was used to deposit thin films on transparent polymer foils, using a confocal configuration with 3 targets of 1-inch diameter [26]. The use of confocal geometry allows one to co-deposit 2 materials from two or more different targets and mix them at the same time to obtain nanocomposite material. For the deposition of thin films on self-adhesive polyurethane foils, we used silicon oxide, titanium oxide and silver targets. Both oxide targets were operated in RF sputtering conditions at 50W applied power. The deposition was performed in argon and argon/oxygen gas mixture at 6 mTorr pressure. The typical deposition time was 30 min., yielding 30 to 35 nm film thicknesses. From this total thickness, it is estimated that only \(\sim\)10% corresponds to Ag, while the other 90% corresponds to the total thickness of the oxide. HIPIMS (high-power impulse magnetron sputtering) was used to sputter the Ag target, enabling fine-tuning of the deposition rate. The pulse characteristics selected for the deposition of Ag were the following: pulse voltage of 650 V, peak current of 1.5 A, pulse duration of 50 \(\upmu\)s and repetition frequency of 1 Hz, with the deposition conditions being the same as in our previous work [26]. Let us note that the main parameter that controls the quantity of Ag in the thin films is the pulsed character of the Ag cathode, enabling fine control of the Ag quantity by tuning the repetition frequency. In the current study, our efforts were focused on improving the quality of the Ag+TiO\({}_{2}\) layer as it was previously shown that the Ag+SiO\({}_{2}\) layer has good antibacterial properties and good optical transparency [26]. According to our previous results, the Ag+TiO\({}_{2}\) layers proved poor transparency in the visible spectral range, one possible cause being the quantity of oxygen in the layer. To compensate for this, the TiO\({}_{2}\) layer was optimized in the current study by adding a small quantity of oxygen to the gas mixture in the deposition process. Initial tests were made with oxygen gas flows between 1 and 7.5% of the total gas flow. It was noted that the oxygen flow should be limited to only a few percent of the total, further leading to a significant decrease in the deposition rate. The most advantageous of the investigated gas flows was found to be at 2.5%, with a deposition rate of only 30% smaller compared with the Ar sputtering process. The deposition time was adjusted accordingly so that the total thickness of the layer remains comparable with the one previously used, around 30 nm. The optical, structural and morphological properties were further analyzed and compared for the different layers obtained. The topography of thin films was analyzed based on atomic force microscope (AFM) images acquired with the AFM/STM Microscopy System (INNOVA VEECO, Berlin, Germany) working in taping mode. The elemental composition of the coatings was determined by Energy-Dispersive X-Ray Spectroscopy (EDS), performed on the scanning electron microscope (SEM, Hitachi TM3030 Plus Tabletop Microscope, Tokyo, Japan) coupled with EDS (FEI Inspects equipment). The EDS spectra were registered for a duration of at least 10 min each in 3 different areas of the samples. A Jasco V-670 double-beam spectrophotometer was utilized to record the transmission and reflectivity spectra of the TiO\({}_{2}\)+Ag and SiO\({}_{2}\)+Ag coatings. The optical characteristics of layers were examined using a Jasco V-670 spectrophotometer (Jasco, Tokyo, Japan) within the Ultraviolet-Visible-Near-Infrared Spectrum. The spectrophotometer was equipped with an ARSN-733 auxiliary module (Jasco, Tokyo, Japan) with a concave mirror and a 60 mm diameter integrating sphere. According to the manufacturer's specifications for the integrating sphere, the potential relative errors for absolute reflectivity measurements are \(\pm\)1.5% for 5\({}^{\circ}\) incidence angles.