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We observe laser-induced grain morphology change in silicon nanopillars under a transmission electron microscopy (TEM) environment. We couple the TEM with a near-field scanning optical microscopy pulsed laser processing system. This novel combination enables immediate scrutiny on the grain morphologies that the pulsed laser irradiation produces. We find unusual transformation of the tip of the amorphous or polycrystalline silicon pillar into a single crystalline domain via melt-mediated crystallization. On the basis of the three-dimensional finite difference simulation result and the dark field TEM data, we propose that the creation of the distinct single crystalline tip originates from the dominant grain growth initiated at the apex of the non-planar liquid–solid interface. Our microscopic observation provides a fundamental basis for laser-induced conversion of amorphous nanostructures into coarse-grained crystals.

Lasers are efficient tools in a variety of micro/nanoscale material processing applications. Even though optical imaging techniques offer convenient in-situ monitoring, their spatial resolution is frequently not sufficient for inspecting the detailed phenomena occurring in micro/nano structures, hence requiring additional characterization tools. Besides the inconvenience, critical processing parameters cannot be readily determined ex situ. In this study, an example of an in-situ monitoring technique for micro/nanoscale laser processing is demonstrated by combining the optical near-field apparatus with a scanning electron microscopy (SEM). In-situ process monitoring under true optical near-field configuration is realized through orthogonal probe manipulation and combined probe-sample translation and tilting apparatus. Catalyst behavior under a chemical vapor deposition (CVD) gas environment coupled with near-field illumination is monitored in an environmental SEM.

Nanoparticle solutions are considered promising for realizing low cost printable high performance flexible electronics. In this letter, excimer laser annealing (ELA) was employed to induce melting of solution-deposited ZnO nanoparticles and form electrically conductive porous films. The properties of the films were characterized by scanning electron microscopy, high-resolution transmission electron microscopy, DC conductance, and photoluminescence measurements. Thin-film field-effect transistors have been fabricated by ELA without the use of conventional vacuum or any high temperature thermal annealing processes. The transistors show n-type accumulation mode behavior with mobility greater than 0.1 cm2/V s and current on/off ratios of more than 104. Optimization and control of the laser processing parameters minimized thermal impact on the substrate. This technique can be beneficial in the fabrication of metal oxide based electronics on heat sensitive flexible plastic substrates using low-cost, large-area solution processing combined with direct printing techniques.