Spontaneous evolution of nanotips on silicon surface below the laser ablation threshold

• Published in: Applied surface science 2011-06, Vol.257 (17), p.7851-7855
• Main Authors: Lugomer, S., Maksimović, A., Karacs, A., Peto, G.
• Format: Article
• Language: English
• Subjects: Arrays; Clusters, nanoparticles, and nanocrystalline materials; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electron and ion emission by liquids and solids; impact phenomena; Evolution; Exact sciences and technology; Impact phenomena (including electron spectra and sputtering); Instability; Laser interaction; Laser-beam impact phenomena; Materials science; Nanomaterials; Nanoscale materials and structures: fabrication and characterization; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Nanostructure; Nonlinear dynamics; Other topics in nanoscale materials and structures; Physics; Silicon; Solitons; Stability; Structure of solids and liquids; crystallography; Surface nanopatterning; Surface structure
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2011.04.045

► Spontaneous evolution of 2D array of Si nanotips under laser irradiation of silicon surface. ► The equidistant nanotips are organized into a square, and the “ V”-shaped patterns. ► The nanotips evolve from the nonlinear flow instability of molten Si layer. ► These localized structures may be identified as the lump solitons. A low power density single-pulse laser irradiation of the Si surface has been used for the study of formation and self-organization of silicon nanotips. A two dimensional regular array of hillock-like nanotips has been created in the central region, a disturbed array comprising crossed lines of hillocks in the near-central region, and the “ V”-shaped array in the peripheral region. Therefore, the long-range organization of hillocks changes from the center toward the periphery, following the Gaussian-like laser power profile. The evolution of hillocks due to the flow instability of molten silicon is equivalent to the instability of a liquid layer falling down a vertical plate. The novel result is that the hillock-like soliton structures can be identified with the lump solitons resulting from the nonlinear hydrodynamic instability evolution.