Improved photocurrent properties of La doped CuO thin films coated by nebulizer spray pyrolysis method for photosensor applications

Abstract

In this study, pure and La of various concentrations (0.5, 1.0, 1.5, 2.0, and 2.5 wt.%) doped CuO thin films were produced by means of the NSP technique to be used as UV photodetection applications. Various physicochemical investigations such as XRD, SEM, PL, UV–Vis, and current-voltage (I–V) characteristics have been conducted to inspect the role of La in the grown films. X-ray diffraction data confirm the single cubic crystal structure and the size of crystallites shrinkages from 22.6 to 19.4 nm. SEM photo shows the formation of triangular prismic shape like morphology. The spectroscopic studies show that the added La impurity promotes their absorption level in the UV region and redshift the optical bandgap from 2.07 to 1.81 eV. Photoluminescence spectral analysis confirms the presence of oxygen vacancies at 413 nm. Upon exposure to a UV light source (λ = 365 nm) the fabricated La-doped CuO thin films offered a better photo-responsivity, detectivity, and external quantum efficiency value of 1.63 × 10−1 AW−1, 1.75 × 1010 Jones, and 107% respectively. Our results provide a guideline to design high-performance UV photodetectors.