Production and characterization of laser-engraved porous silicon

• Grant number: 24/16151-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Ulisses Ferreira Kaneko
• Grantee: Hermes Moreira Velloso
• Host Institution: Instituto de Geociências e Ciências Exatas (IGCE). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil

Abstract

Porous silicon is a nanomaterial with a sponge-like structure that can be applied in various and diverse fields, ranging from optics and photonics to biomaterials and tissue engineering. This broad range of applications can be explained by its large surface area due to the porous structure, as well as its electro- and photoluminescence, which arise from quantum confinement effects. Despite the potential of porous silicon, progress in the development of this material has been hindered by the use of hydrofluoric acid (HF) in an electrochemical process as the primary production method. HF is toxic, corrosive, dangerous, and can be extremely harmful to the environment if improperly disposed of. This project aims to develop a method for producing porous silicon through laser engraving. In addition to eliminating the need for HF, this method is clean, dry, and avoids the use of any other chemicals. Porous silicon will be produced on the surface of an n-type Si(100) wafer using a pulsed ns laser with a wavelength of 532 nm. To validate the laser-produced material, its structural, morphological, and optical properties will be investigated using Raman spectroscopy, nitrogen gas adsorption, and photoluminescence spectroscopy. If successful, these procedures could demonstrate the reproducibility of the method and confirm that the laser-engraved material is indeed porous silicon.