Publication Details
Abstract
Nanostructured porous silicon (PS) has emerged as a promising material due to its unique electronic and optical properties, which are influenced by fabrication techniques and etching parameters. Photochemical etching using sunlight as a natural energy source (S.L.PCE) offers a cost-effective, environmentally friendly alternative to industrial light sources. While prior studies explored porous silicon formation using artificial illumination, limited research has focused on the effects of etching time under concentrated sunlight. This study investigates the impact of varying etching durations (40–70 minutes) on the morphology and structural properties of PS layers formed on (111) N-type silicon wafers. Using a convex lens to focus sunlight and a fixed 40% HF concentration, etching was performed, and atomic force microscopy was employed to assess topography, thickness, and particle distribution. The results demonstrate that increased etching time leads to thinner wall structures, smaller nanoparticle diameters (101.18 nm to 66.36 nm), and thicker porous layers (9.79 nm to 51.38 nm), accompanied by an increase in surface roughness and RMS values. Statistical analysis showed negatively skewed and high-kurtosis particle size distributions, indicating non-normal distribution shapes with sharper peaks. The study is among the first to systematically evaluate the influence of solar-based etching duration on PS layer characteristics using real sunlight, avoiding artificial heating and vapor hazards. Findings offer insights for optimizing low-cost, green fabrication of nanoscale silicon for potential applications in optoelectronics, photodetectors, and sensing technologies.