Alfredo Benítez Lara

This work focuses on developing resistive switching (RS) devices using thermally annealed (TA) SiO₂/Si multilayers (ML). Three SiO₂/Si bilayers were deposited with an additional 10 nm SiO₂ layer as a dielectric barrier layer on top of the ML. The SiO₂ layers were 6 nm thick, while the thickness of the Si layers varied from 2, 4, and 6 nm, and were labeled as ML-62, ML-64, and ML-66, respectively. X-ray photoelectron spectroscopy analysis revealed well-defined ML structures before TA. However, after TA, samples ML-64 and ML-62 showed discontinuities due to diffusion between neighboring Si layers, increasing the dimensions of the Si-rich regions. In fact, the concentration of elemental Si (Si⁰) within the intermediate Si layer increases as the Si layer becomes thinner. Consequently, the size of Si-nanocrystals, created after TA, increases from 6 to 8.5 nm for ML-66 to ML-62, as confirmed by Raman and transmission electron microscopy analysis. The composition discontinuities and loss of the ML structure resulted in erratic electrical behavior, with an electroforming (EF) voltage as high as −14 V in sample ML-62. For the ML-66, which retained the ML structure, the EF voltage was reduced to −4 V, showing SET/RESET values of around ±3 V and stable electrical behavior, with an ON/OFF ratio of up to seven orders of magnitude. This demonstrates the importance of the ML design in the operation of RS devices.

Alumina (Al₂O₃) is a key material in inorganic and hybrid electronics due to its excellent dielectric, chemical, and thermal stability properties. In this work, we present the first results of alumina films deposited by ultrasonic spray pyrolysis (USP) at low temperatures (40–100 °C) using water as the sole solvent, followed by an annealing step at 100 °C. The films were characterized by SEM, XRD, EDS, and UV-Vis spectroscopy to evaluate their morphology, structure, composition, and optical properties. Preliminary results show an average thickness of approximately 8 µm, with surface features consisting of agglomerates (average particle size ≈ 7.252 µm) distributed over the film. XRD patterns revealed the presence of tetragonal and orthorhombic phases, while EDS confirmed the presence of aluminum and oxygen with slight compositional variations depending on deposition and annealing conditions. UV-Vis absorption spectra exhibited characteristic bands between 259 nm and 263 nm. These results provide a comprehensive understanding of the optical, structural, and morphological behavior of Al₂O₃ films processed at low temperatures. The motivation for studying these films is to enable more eco-friendly gate oxides for organic MIS structures, as well as functional layers in photonic devices. This approach represents a sustainable and straightforward route for obtaining Al₂O₃ coatings compatible with temperature-sensitive substrates, paving the way for future applications in hybrid and organic electronics.

Pertenecemos a la línea Análisis Institucional en Acontecimientos Migratorios en la Universidad Nacional de la Patagonia Austral. Desarrollamos desde hace aproximadamente 20 años, tareas de investigación, intervención, formación y difusión de avances de conocimiento. Del listado amplio de asuntos sugeridos desde la coordinación de esta reunión científica para organizar la contribución en esta mesa, focalizamos en cuatro asuntos: