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

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.