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

摘要

A hybrid structure, which integrates the nanostructured silicon with a bio-active silicate, is fabricated using the method of MHz sonication in the cryogenic environment. Optical, atomic force, and scanning electron microscopy techniques as well as energy dispersive X-ray spectroscopy were used for the investigation of the morphology and chemical compound of the structured surface. Micro-Raman as well as X-ray diffraction, ellipsometry, and photovoltage spectroscopy was used for the obtained structures characterization. Ellipsometer measurements demonstrated the formation of the layer with the thicknesses ~700?nm and optical parameters closed to SiO~(2) compound with an additional top layer of the thicknesses ~15?nm and the refractive index ~1. Micro-Raman investigation detects an appearance of Ca–O local vibrational mode, and the stretching vibration of SiO~(4) chains characterized the wollastonite form of CaSiO~(3). A significant rise in the value and an expansion of the spectral range of the surface photovoltage for silicon structured via the megasonic processing was found. The concept of biocompatible photovoltaic cell on the base of SiCaSiO~(3) structure for the application in bioelectronics was proposed.