Anodic etching of crystalline silicon in fluoride-based electrolyte and optimization of the etching conditions aimed at the fabrication of porous silicon for gas chemosensors applications are presented. The main goal of the study was to prepare mechanically stable material containing luminescent silicon nanocrystals.
The main optimization parameters were anodic current density, etching electrolyte composition, and the silicon wafer properties (type of doping, resistivity, crystallographic orientation). The optimized fabrication parameters were determined from gravimetry, linear voltammetry of silicon wafer in the fluoride-based electrolytes, and characterization techniques like infrared and photoluminescence spectroscopy and scanning electron microscopy.