Silicon Substrate Strained and Structured via Cavitation Effect for Photovoltaic and Biomedical Application

Area of Science:

• Materials Science
• Nanotechnology
• Bioelectronics

Background:

• Silicon (Si) is a cornerstone material in electronics, but its integration into biological systems faces challenges.
• Bio-active silicates offer biocompatibility, presenting an opportunity for novel hybrid materials.
• Cryogenic processing can enable unique nanostructures and material properties.

Purpose of the Study:

• To fabricate a hybrid nanostructured silicon and bio-active silicate material.
• To characterize the structural, optical, and electrical properties of the fabricated material.
• To explore the potential of the Si\CaSiO3 structure for bioelectronic applications, particularly in biocompatible photovoltaic cells.

Main Methods:

• Fabrication of the hybrid structure using MHz sonication in a cryogenic environment.
• Morphological and chemical analysis using optical microscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS).
• Characterization of optical and electrical properties using micro-Raman spectroscopy, X-ray diffraction (XRD), ellipsometry, and surface photovoltage (SPV) spectroscopy.

Main Results:

• Formation of a ~700 nm SiO2-like layer with a ~15 nm top layer (refractive index ~1).
• Micro-Raman spectroscopy confirmed the presence of Ca-O bonds and SiO4 chains, indicating the wollastonite form of CaSiO3.
• Significant enhancement in surface photovoltage (SPV) value and spectral range observed for megasonic-processed silicon.

Conclusions:

• A novel Si\CaSiO3 hybrid nanostructure was successfully fabricated via cryogenic MHz sonication.
• The material exhibits promising optical and enhanced photovoltage properties.
• The developed Si\CaSiO3 structure holds potential for creating biocompatible photovoltaic cells for bioelectronics.