Substrate selection and characterization in infrared detector design for sorting systems

In the production of optoelectronic devices such as photodiodes, photodetectors, and solar cells, the nano-crystalline scale of porous silicon substrates attracts interest. Four samples of porous silicon have been created using the laser-assisted electrochemical etching approach from n-type silicon wafers with a (1000) orientation. To describe and examine the topographical, morphological, structural, and spectroscopic characteristics of the synthesized substrates, FESEM, AFM, XRD, and photoluminescence were employed, respectively. The initial and crucial step in designing high detectability and sensitivity photoreactors for discriminating between different types of plastics involves preparing porous silicon substrates. Porous silicon substrates are highly effective in constructing efficient photodetectors due to their increased surface area, enhancing detection capabilities. Their surface roughness provides a robust base for depositing the detector’s primary materials. In this study, porous silicon was prepared under specific conditions: 40% acid concentration, etching times of 5 min at current strengths of 10 mA/cm² for the first sample and 20 mA/cm² for the second sample.