Investigation of the Influence of Adhesion Layers on the Gas Sensing Performance of CuO/Cu2O Thin Films

This parameter study examines the impact of two distinct adhesion layers, chromium (Cr) and titanium (Ti), on the performance of CuO/Cu2O-based chemoresistive gas sensors by varying the layer thickness. The sensing material utilised on a Si-SiO2 sensor chip with Pt electrodes is an ultrathin CuO/Cu2O film fabricated through thermal deposition of Cu and subsequent oxidation. The sensors were evaluated by measuring the change in electrical resistance against a range of target gases, including carbon monoxide (CO), carbon dioxide (CO2) and a mixture of hydrocarbons (HCMix), in order to assess any potential cross-sensitivity issues. As the reactions occur at the surface, the surface was characterised by scanning electron microscopy (SEM) and the composition by grazing incidence X-Ray diffraction (GIXRD) measurement to gain further insight into the influence of the adhesion layer on the sensing performance.