Tailoring AgO-Doped CdS Nanostructures on Porous Silicon via PLD for High-Performance H2S and NO2 Gas Sensors
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This work presents the fabrication of highly efficient gas sensors based on silver oxide (AgO)- doped cadmium sulfide (CdS) nanostructures deposited on porous silicon (PS) substrates using pulsed laser deposition (PLD). Three doping concentrations of AgO (5, 10, and 15%) were investigated to evaluate their influence on the structural, optical, and gas sensing properties of CdS. The prepared films were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), UV–Vis spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The XRD results confirmed enhanced crystallinity with increasing AgO concentrations, while FESEM and AFM analyses revealed a nanostructured surface with increased roughness and active surface area. UV–Vis measurements showed a reduction in the optical band gap upon AgO incorporation, whereas FTIR spectra confirmed the successful formation of AgO:CdS heterostructures. Gas-sensing measurements demonstrated that the CdS with 5% AgO sensor exhibited the highest NO₂ sensing response of 92.8% at an operating temperature of 100°C. The enhanced sensing performance is attributed to the synergistic effect of AgO/CdS heterostructure formation, increased adsorption sites, and improved charge transfer through the PS substrate. The developed AgO:CdS/PS platform offers tunable sensing behavior by controlling dopant concentration and operating temperature, making it a promising candidate for high-performance toxic gas sensing applications.
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© 2023 The Author(s). Published by the College of Science, University of Baghdad. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License.
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