Fabrication and characterization of PSi/nanometal hybrid structures by laser for CO gas sensor

Abstract

AbstractMesoporous silicon (mesoPSi) layers fabricated by the photoelectrochemical etching (PECE) method in hydrofluoric acid (HF) are active as carbon monoxide gas sensors. The modified porous silicon (PSi) can be used with noble metals to manufacture an effective gas sensor. Embedded gold, platinum, and palladium nanoparticles Au, Pt, and Pd-NPs could modify the surface morphology of mesoPSi and form mesoPSi/AuPtPd-NPs hybrid structures through a simple and dipping process in fixed salt concentrations. The morphology of the hybrid structures has been studied using scanning electron microscopy and X-ray diffraction. The prepared gas sensor has measured the electrical characteristics at room temperature. Shape, nanoparticle size, and specific surface area strongly influenced the currentâvoltage characteristics. The results show that Au, Pd, and Pt-NPs sizes prepared by the dipping process for mesopore-like structures were in the range from 0.64 to 7.53 nm. Besides, considerable improvements in the response, recovery times and sensitivity of gas sensor were noticed when decreasing the incorporated Au, Pd, and Pt-NPs to the mesoPSi matrix.