Photodetection Performance Enhancement of Crystal-like Co3O4 Nanostructure Synthesized via Pulsed Laser Deposition

Abstract

Crystal-like Cobalt Oxide (Co₃O₄) nanostructures synthesized on a Copper Oxide (CuO) layer can enhance charge separation and improve the optoelectronic properties. To achieve a high response photodetectcor, copper oxide (CuO) thin films were used to match the quartz substrate with (Co₃O₄), which is leads to the high-density, crystal-like of Co₃O₄ nanostructures using a combination of thermal evaporation and pulsed laser deposition (PLD) techniques. Copper (Cu) was first deposited on quartz substrates via thermal evaporation under vacuum conditions and subsequently oxidized at 700 °C to form CuO. and then in the next stage, cobalt (Co) was deposited using Pulsed Laser Deposition (PLD) technique, which is followed by oxidation process at temperatures up to 900 °C to grow the desired crystal-like Co₃O₄ nanostructures. X-ray diffraction (XRD) and Field Emission Electron Microscopy (FE-SEM) were used to investigate the structural and morphological properties of the produced films; optical properties using UV-visible spectroscopy were also investigated. Crystal-like Co₃O₄ exhibited significantly improved current–voltage (I–V) characteristics, with high detectivity. The dark current and photocurrent of the metal–semiconductor–metal (MSM) photodetector fabricated on Co₃O₄ were 8.14 μA and 442 μA, respectively. Response and recovery times of 7.4 s and 9.1 s for this detector. An MSM photodetector with aluminum (Al) contact electrodes was fabricated on both layers. The rectifying behavior of I–V curve, suggesting that the surface states or defect levels in Co₃O₄ are relatively low.