Regensburg 2022 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
MM: Fachverband Metall- und Materialphysik
MM 18: Poster Session 2
MM 18.34: Poster
Tuesday, September 6, 2022, 17:30–20:00, P2
Fabrication of hierarchical porous silicon and amorphous silica by means of silver nanoparticle catalyzed chemical etching — •Stella Gries1,2,3, Manuel Brinker1,2,3, and Patrick Huber1,2,3 — 1Institute for Materials and X-Ray Physics, Hamburg University of Technology, 21073 Hamburg, Germany — 2Center for X-Ray and Nano Science CXNS, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany — 3Center for Hybrid Nanostructures CHyN, University of Hamburg, 22607 Hamburg, Germany
Many biological tissues and materials exhibit a multiscale porosity with small, often nanoscale pores as well as large, macrosocpic pores or capillaries in order to achieve simultaneously large inner surfaces in combination with an optimized mass transport capability. Achieving such a hierarchical porosity in artificial porous media is a very active research field. Here we present a novel approach based on silver nanoparticle-assisted chemical etching (MACE)of electrochemically fabricated macroporous silicon for the synthesis of wafer-scale,single-crystalline silicon with a bimodal pore size distribution. With MACE macroporous silicon membranes can be porosified into hierarchical porous silicon (hp-Si). The resulting semiconducting material offers good hydraulic permeabilities and simultaneously a large inner surface for potential applications in energy harvesting or conversion or for on-chip sensorics and actuorics. Finally, the hp-Si membranes can be transformed by thermal oxidation at temperatures above 800°C to hierarchical porous amorphous silica a material that could be of particular interest for opto-fluidic and photonic applications in the visible.