Core–shell hybrid structured rGO decorated ZnO nanorods synthesized via a facile chemical route with photosensitive properties

Abstract

Two-dimensional graphene-based nanocomposites have gained much attention due to their promising applications in electronic and optoelectronic devices. We report the fabrication of c-axis-oriented ZnO nanorods (ZnO (NR)) and a ZnO (NR)–rGO core–shell structure on a glass substrate via chemical bath deposition and hydrothermal approaches. The structural, morphological, and optical characteristics of the synthesized nanostructures have been studied in depth via XRD, FE-SEM, AFM, Raman, UV-vis spectroscopy, and photoluminescence spectroscopy analysis. The homogeneous core–shell distribution was revealed via SEM and UV-vis spectroscopy. Raman spectroscopy demonstrated the presence of rGO within the pores of the ZnO (NR) array. The electrical properties of ZnO (NR) with {0001} facets and ZnO (NR) coated with rGO studied under different illumination conditions clearly suggest the huge potential of the core–shell geometry for UV-photodetector applications. Further, improvements in the degradation and stability properties of the ZnO (NR) and rGO composite were analyzed. UV excitation of the core–shell device may induce energetic electrons to jump from the ZnO surface to the rGO layer, thereby increasing the photocurrent. These results indicate that the incorporation of rGO into a ZnO matrix with core–shell geometry has great promise for other optoelectronic applications, including photovoltaics.