Structural and Optoelectronic Characteristics of Nanostructured Multilayer CuO/ZnO Heterojunction for UV and Visible Laser Photodetectors

Abstract

In this work, the dc reactive sputtering technique was used to fabricate multilayer structures from nanostructured copper oxide (CuO) and zinc oxide (ZnO) thin films on indium-doped tin dioxide (ITO) substrates. The structural and morphological characteristics of these samples were introduced by the X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM). As well, the spectral responsivity and external quantum efficiency (EQE) of the fabricated heterojunction were determined to show their feasibility as multi-wavelength photodetectors. The optimum heterojunction showed maximum responsivity of 0.83 and 0.59 A/W at 347 and 585 nm, respectively. Also, it showed maximum EQE of 1.45 and 0.62 at 347 and 585 nm, respectively.