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Santos, R., J. Loureiro, A. Nogueira, E. Elangovan, J. V. Pinto, J. P. Veiga, T. Busani, E. Fortunato, R. Martins, and I. Ferreira, "Thermoelectric properties of V2O5 thin films deposited by thermal evaporation", Applied Surface Science, vol. 282, pp. 590-594, 2013. AbstractWebsite
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Santos, L., P. Wojcik, J. V. Pinto, E. Elangovan, J. Viegas, L. Í. Pereira, R. Martins, and E. Fortunato, "Structure and Morphologic Influence of WO3 Nanoparticles on the Electrochromic Performance of Dual-Phase a-WO3/WO3 Inkjet Printed Films", Advanced Electronic Materials, pp. n/a-n/a, 2015. AbstractWebsite

The optimization of tungsten trioxide (WO3) nanoparticles produced via hydrothermal synthesis for application in electrochromic (EC) devices is reported. The structure and morphology of the nanoparticles are controlled by changing the acidity of the aqueous solvent added to the sol-gel precursor (peroxopolytungstic acid) during synthesis. Orthorhombic hydrated WO3 nanorods or monoclinic WO3 nanoslabs are obtained when HCl is added, while synthesis only in aqueous medium results in a mixture of both types of polymorphs. Dual-phase thin films are processed by inkjet printing deposition of the nanoparticles in flexible polyethylene terephthalate substrate with indium tin oxide coating (ITO PET) followed by the deposition of the precursor solution. When compared with purely amorphous tungsten oxide films, the dual phase ones present higher optical densities and improved capacity, and cyclability stability. The best results, obtained for orthorhombic hydrated nanoparticles (ortho-WO3·0.33H2O), are due to its high surface area and improved conductivity. Additionally, the ex situ X-ray diffraction (XRD) lithiation studies show evidence of a higher distortion of the monoclinic when compared with the orthorhombic crystallographic structure, which contribute to the inferior EC performance. These results validate the use of inkjet printing deposition with low processing temperatures for EC dual-phase thin films containing optimized nanoparticles which are compatible with low-cost substrates.

Savoini, B., D. Caceres, R. Gonzalez, Y. Chen, J. V. Pinto, R. C. da Silva, and E. Alves, "Copper nanocolloids in MgO crystals implanted with Cu ions", Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms, vol. 218, pp. 148-152, 2004. AbstractWebsite
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Savoini, B., R. Gonzalez, J. V. Pinto, R. C. da Silva, and E. Alves, "Copper and cobalt nanocolloids in implanted MgO crystals", Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms, vol. 257, pp. 563-567, 2007. AbstractWebsite
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Silva, D., C. S. Monteiro, S. O. Silva, O. Frazão, J. V. Pinto, M. Raposo, P. A. Ribeiro, and S. Sério, "{Sputtering Deposition of TiO2 Thin Film Coatings for Fiber Optic Sensors}", Photonics, vol. 9, no. 5: MDPI AG, pp. 342, may, 2022. Abstract

Thin films of titanium dioxide (TiO2) and titanium (Ti) were deposited onto glass and optical fiber supports through DC magnetron sputtering, and their transmission was characterized with regard to their use in optical fiber-based sensors. Deposition parameters such as oxygen partial pressure, working pressure, and sputtering power were optimized to attain films with a high reflectance. The films deposited on glass supports were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Regarding the deposition parameters, all three parameters were tested simultaneously, changing the working pressure, the sputtering power, and the oxygen percentage. It was possible to conclude that a lower working pressure and higher applied power lead to films with a higher reflectance. Through the analysis of the as-sputtered thin films using X-ray diffraction, the deposition of both Ti and TiO2 films was confirmed. To study the applicability of TiO2 and Ti in fiber sensing, several thin films were deposited in single mode fibers (SMFs) using the sputtering conditions that revealed the most promising results in the glass supports. The sputtered TiO2 and Ti thin films were used as mirrors to increase the visibility of a low-finesse Fabry–Perot cavity and the possible sensing applications were studied.