Room temperature gas sensor based on La2O3 doped CuO thin films

In this work, undoped and lanthanum doped cupric oxide (CuO:La) nanorods structured thin films were deposited at different concentrations (CLO) on p-type silicon substrates using the spray pyrolysis technique at 350 °C. XRD, AFM, SEM, and EDX techniques were used to investigate the structural, morphological, and compositional analysis, respectively. A decrease in crystallite size was observed from 13.4 to 7.75 nm and even the peak diffraction intensity decreased with an increase in La concentration. The hexagonal structure of the La2O3 phase with poor orientation planes was observed at 7 wt% La. Amplitude parameters, grain size, and atoms distribution were discussed from AFM analysis. SEM images show a uniform distribution and homogeneous crystalline construction supported by quadrilateral pillars with nanorods-like in shape. The sensitivity, recovery, and response time for CLO thin films as room temperature NO2 sensor devices were calculated. The effect of lanthanum concentration on the sensing mechanism of CuO thin films also has been reported.