Negative photoconductance in NiO/B-rGO nanocomposite-based UV photodetector: Structural and Photoelectric properties

Abstract

The manifestation of uncommon negative photoconductance (NPC) in semiconductor materials has recently emerged as a significant breakthrough in various research applications. Despite its potential, nickel oxide (NiO), a transition metal oxide, has not been extensively explored in optoelectronic applications. However, when combined with carbon materials such as graphene oxide (GO), NiO demonstrates considerable promise. Additionally, doping GO with acceptor atoms like boron can modify its electronic behavior and enhance its functionality. In this study, we present a straightforward synthesis and preparation method for NiO/B-rGO nanocomposite, followed by their integration into UV photodetector devices. We investigate their structural and morphological characteristics using various analytical techniques. Furthermore, electrical characterization via I–V curve analysis is conducted to assess their photoresponse and reveal their photoconductance behavior. The results highlight negative photoconductance (NPC) under UV photoexcitation compared to the dark case, with this behavior is attributed to the trapping and recombination processes of carriers, which is thoroughly discussed, and supported by electrical noise evaluation. Additionally, the performance of the NiO/B-rGO device demonstrates superior photoresponse, with a responsivity of 0.92 A/W and a detectivity of 1.38 × 101⁰ Jones at low reverse bias.