Electrical properties of CuO nanoflakes/Au heterojunction under photo excitation

Cupric oxide (CuO) nano-materials have been of emerging research interest due to its application in electronic devices and sensors. In this work, the junction properties of the CuO nanoflakes (NFs) have been analyzed. From the field emission scanning electron microscopy (FESEM) studies, the morphology of the sample is confirmed to be two-dimensional nanoflakes with variable sizes. The composition ratio (Cu:O) of the sample was found to be nearly 1:1 from the energy dispersive x-ray spectroscopy (EDS) analysis. Quantum confinement induced blue shifting of the band gap to 1.48 eV was evidenced from the UV–Vis absorption spectroscopy of the NFs. The junction properties of the indium tin oxide (ITO)/CuO NFs/gold (Au) device show a distinct diode characteristic with barrier heights 2.59 V and 2.49 V and ideality factor 0.97 and 0.95 under dark and illumination conditions respectively, suitable for photo-sensor applications.