Proceedings of International Conference on Applied Innovation in IT  ·  2026/03/31  ·  Vol. 14  ·  Issue 1  ·  pp. 767–773
Data-Driven Gas Sensing Analysis of Ag-Doped Cdo Thin Films
Esraa Kareem Jasem, Abdul-Lateef Abdul-Jabar, Mushtaq Talib Hamzah, Muhaned Zaidi and Saja Faez Hassan
📄 Download PDF DOI: 10.25673/123634
Abstract
Pure and Ag-doped CdO thin films were successfully synthesized using the chemical spray pyrolysis (CSP) technique. The influence of silver doping on the structural, morphological, optical, and gas-sensing properties of CdO films was systematically investigated. X-ray diffraction analysis confirmed the formation of polycrystalline CdO films with a preferred orientation along the (111) plane. An increase in crystallite size from 17.78 nm for pure CdO to 23.55 nm for 4% Ag-doped CdO was observed, accompanied by a reduction in dislocation density and microstrain, indicating improved crystalline quality. Atomic force microscopy revealed smoother and more compact surfaces with increasing Ag concentration. Optical investigations in the wavelength range of 300–900 nm demonstrated a decrease in transmittance and a narrowing of the optical bandgap from 2.65 eV to 2.55 eV as the Ag doping level increased. The observed bandgap reduction was attributed to the formation of localized impurity states within the CdO lattice. Furthermore, the extinction coefficient and refractive index were found to vary significantly with Ag incorporation. Gas-sensing measurements toward NO₂ gas indicated that pure CdO films exhibited higher sensitivity compared to Ag-doped samples. The reduction in sensitivity with increasing Ag concentration was associated with enhanced charge-carrier recombination and a decrease in active adsorption sites on the film surface. The obtained results demonstrate that Ag doping effectively modifies the physical properties of CdO thin films and influences their suitability for gas-sensing applications.
Keywords
Cdo Thin Films Silver-Doped Spray Pyrolytic Growth Structural Properties Optical Bandgap Refractive Index Gas Sensing.
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