Synthesis and characterization of nickel oxide nanoparticles decorated graphene oxide for fast-response UV photodetector: unveiling of negative photoconductance

Nickel oxide, classified as a metal oxide, has attracted considerable attention across various applications. Nevertheless, its utilization in optoelectronics applications remains relatively uncommon. This study presents a cost-effective and straightforward chemical synthesis method to produce nickel oxide (NiO) nanoparticles decorated graphene oxide (GO) to improve the performance of a UV photodetector. The NiO/GO nanomaterial was prepared using a co-precipitation approach, followed by an annealing process at 400 °C. Various characterization techniques, including field emission scanning electron microscopy (FESEM), transmission electron microscopy, X-ray diffraction, and Raman spectroscopy, were performed to analyze the nanomaterial. The UV photodetector was electrically characterized to determine responsivity, detectivity, and temporal responses under both dark and UV-illuminated conditions at 375 nm. A detailed analysis of the current–voltage (I–V) curve was conducted to identify the presence of negative photoconductivity in the device. The results revealed an impressive photoresponse in the NiO/GO nanocomposite with a better responsivity of 2.17 A/W, a significant detectivity 2.3 × 1010 Jones, and good rise/fall times of 1.76/1.01 s under reverse bias conditions. These findings signify a novel trend for the next generation of photodetectors, incorporating multifunctional aspects.