High responsivity n-ZnO/p-CuO heterojunction thin film synthesised by low-cost SILAR method for photodiode applications

In this report, we have prepared n-ZnO/p-CuO heterojunction thin film by low-cost SILAR method and made a comparative study with physical properties of ZnO and CuO thin film photodetectors. The prepared heterojunction film is exhibit mixture of hexagonal structure of ZnO and monoclinic structure of CuO. All the films have uniform surface morphology without any voids and ensured that the presence of used elements like Zn, Cu, and O. The optical absorption spectrum declared that comparatively high photon absorption in the range of 2–6% occurred in 365 nm of UV light. The photoluminescence spectrum notices that different kind of point defects are present in the prepared heterojunction film. The photo sensing results announce that the ZnO/CuO heterojunction film exist a good photodiode characteristic behavior with good responsivity of 43.69 × 10⁻² A/W.