Morphological and optical properties of aluminum nanoparticles deposited by thermal evaporation on heated substrates

• Published in: Surface & coatings technology 2018-06, Vol.343, p.160-165
• Main Authors: Lachebi, Ines, Fedala, Abdelkrim, Djenizian, Thierry, Hadjersi, Toufik, Kechouane, Mohamed
• Format: Article
• Language: English
• Subjects: Absorption; Aluminum; Aluminum nanoparticles; Atomic force microscopes; Atomic force microscopy; Deposition; Evaporation; Morphology; Nanoparticle formation; Nanoparticles; Optical properties; Plasmonic; Scanning electron microscopy; Substrates; Thermal evaporation
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2017.09.061

In the present work, aluminum nanoparticles (Al-NPs) are deposited by thermal evaporation on heated substrates without additional annealing process after deposition on silicon (100) and corning glass. Their morphological and optical properties are investigated by Scanning Electron Microscopy (SEM), Atomic Force Microscope (AFM), and Optical Transmission Technique. The substrate temperature was varied from 200 to 580°C and the mass thickness between 4 and 23nm. Al-NPs are well formed in all deposition temperatures with a mass thickness of 15nm in one-step. The mean diameter of Al-NPs rises from 50 to 91nm as the deposition temperature increases from 200 to 500°C, and then it remains nearly unchanged in the range of 500–580°C. When the mass thickness increases from 4 to 23nm at 400°C deposition temperature, the NPs size increases from 15 to 135nm. The NPs turn into irregular in shape and their coverage density increases strongly. Under some conditions, the Al-NPs exhibit a broad absorption in the near ultraviolet range. This is attributed to the Localized Surface Plasmon Resonances (LSPRs) absorption. The deposition temperature and the aluminum mass thickness are the key parameters for controlling the Al-NPs size. Based on the obtained results, a formation mechanism of NPs is proposed when ultra-thin film aluminum is deposited on heated substrates. •Deposition of aluminum nanoparticles by thermal evaporation on heated substrates.•Deposition temperature and mass thickness controls the nanoparticles size.•Aluminum nanoparticles are obtained at 200°C.•A model about the formation mechanisms of the aluminum nanoparticles is suggested.