nl9b02568_si_002.avi (3.59 MB)
Kinked Silicon Nanowires: Superstructures by Metal-Assisted Chemical Etching
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posted on 2019-10-15, 19:39 authored by Georgiana Sandu, Jonathan Avila Osses, Marine Luciano, Darwin Caina, Antoine Stopin, Davide Bonifazi, Jean-François Gohy, Alejandro Silhanek, Ileana Florea, Mounib Bahri, Ovidiu Ersen, Philippe Leclère, Sylvain Gabriele, Alexandru Vlad, Sorin MelinteWe
report on metal-assisted chemical etching of Si for the synthesis
of mechanically stable, hybrid crystallographic orientation Si superstructures
with high aspect ratio, above 200. This method sustains high etching
rates and facilitates reproducible results. The protocol enables the
control of the number, angle, and location of the kinks via successive
etch-quench sequences. We analyzed relevant Au mask catalyst features
to systematically assess their impact on a wide spectrum of etched
morphologies that can be easily attained and customized by fine-tuning
of the critical etching parameters. For instance, the designed kinked
Si nanowires can be incorporated in biological cells without affecting
their viability. An accessible numerical model is provided to explain
the etch profiles and the physicochemical events at the Si/Au–electrolyte
interface and offers guidelines for the development of finite-element
modeling of metal-assisted Si chemical etching.