Gas Sensing behaviour of Fe-doped CuO thin films with structural, morphological and optical insights

In the present study, Fe-doped CuO thin films were successfully deposited by the spray pyrolysis technique, and their structural, morphological, optical, and gas sensing properties were systematically investigated. XRD analysis confirmed the formation of monoclinic CuO with improved crystallinity after Fe incorporation, without the formation of secondary phases. FE-SEM analysis revealed significant morphological modifications, with Fe doping leading to a more uniform and compact surface with well-defined grains. The UV study indicates an improved band gap by 0.9 eV.  These structural, morphological and optical changes contributed to the improved gas sensing performance of the films. The Fe-doped CuO thin films exhibited an enhanced response toward H₂ gas, with a maximum gas response of 63%. The improved sensing behaviour can be attributed to Fe-induced modifications in the surface morphology, grain structure, and active surface sites, which enhance the interaction between the sensing layer and H₂ molecules. Thus, Fe incorporation is an effective approach for tailoring the properties of CuO thin films and improving their potential for H₂ gas sensor applications.

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