Hierarchical Porous Silicon: Morphological Investigations
- Abstract number
- European Microscopy Congress 2020
- Corresponding Email
- [email protected]
- PSA.4 - Batteries & Materials for Energy Conversion
- Dagmar Rings (1), Stella Gries (1), Prof. Patrick Huber (1)
1. Hamburg University of Technology, Institute of Materials Physics and Technology
electron tomography, nanostructured silicon, porosity
- Abstract text
Nanostructures of silicon, which is the most important material in semiconductor industry, attract attention because of their great potential applications. The particular nanoporous silicon combines interesting mechanical properties like high surface area and low density with the semiconductor properties of silicon. There are numerous potential applications, for example in photovoltaics , thermoelectrics  or anode materials of Li-ion batteries .
Many mechanical, electrical and optical properties of silicon depend on its structure and porosity. Therefore, it is very important to investigate the morphology and porosity of these materials.
In this work we present morphological examinations of hierarchical porous silicon, which was synthesized using a new approach by further porosifying an already macroporous silicon membrane with smaller mesopores. The goal is to obtain an isotropic mesoporous network in the already existing macroporous silicon membrane.
After filling the porous structure with epoxy resin, we prepared the samples with FIB to obtain reasonably thin specimens of the material. Then we investigate the samples with various methods of Electron Microscopy (SEM, TEM, electron tomography).
Initial results show a high degree of porosity in the macropores walls with no decay of the macrostructure (Fig.1 and 2).
Figure 1: SEM-image of the porous silicon after the further porosifying. Figure 2: SEM-image of the hierarchical porous silicon with a view on the macropores of the silicon membrane.
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