Nanostructured Silicon Matrix for Materials Engineering

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2023-03, Vol.19 (12), p.e2206318-n/a
• Main Authors: Liu, Poting, Schleusener, Alexander, Zieger, Gabriel, Bochmann, Arne, Spronsen, Matthijs A., Sivakov, Vladimir
• Format: Article
• Language: English
• Subjects: Atomic structure; Functional materials; Kinetic energy; Materials engineering; Metalorganic chemical vapor deposition; Molecular motion; nanocapillary; Nanostructure; Nanotechnology; Nanowires; Oxidation; Penetration depth; phase control; Phase distribution; Planar structures; Reagents; Reducing agents; Silicon; silicon nanowires; Synchrotron radiation; Synchrotrons; tin oxides; XANES
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202206318

Tin‐containing layers with different degrees of oxidation are uniformly distributed along the length of silicon nanowires formed by a top‐down method by applying metalorganic chemical vapor deposition. The electronic and atomic structure of the obtained layers is investigated by applying nondestructive surface‐sensitive X‐ray absorption near edge spectroscopy using synchrotron radiation. The results demonstrated, for the first time, a distribution effect of the tin‐containing phases in the nanostructured silicon matrix compared to the results obtained for planar structures at the same deposition temperatures. The amount and distribution of tin‐containing phases can be effectively varied and controlled by adjusting the geometric parameters (pore diameter and length) of the initial matrix of nanostructured silicon. Due to the occurrence of intense interactions between precursor molecules and decomposition by‐products in the nanocapillary, as a consequence of random thermal motion of molecules in the nanocapillary, which leads to additional kinetic energy and formation of reducing agents, resulting in effective reduction of tin‐based compounds to a metallic tin state for molecules with the highest penetration depth in the nanostructured silicon matrix. This effect will enable clear control of the phase distributions of functional materials in 3D matrices for a wide range of applications. The proposed paper provides a fundamental understanding of the phase‐selective deposition of tin oxide phases in a matrix of silicon nanowires. These results show that the formation of byproducts as well as the enhanced motion of molecules in the nanocapillary and their interaction within the nanocapillary lead to the localized reduction of tin oxide, as a promising approach for nanomaterials engineering.