Graphene-Anchored p-Type CuBO₂ Nanocrystals for a Transparent Cold Cathode

CuBO₂ nanostructures were synthesized by employing a low-cost hydrothermal technique to combine into the CuBO₂-RGO nanocomposite for the first time using chemically prepared graphene sheets. The nanohybrid samples were characterized for structural information using X-ray diffraction (XRD) that revealed the proper crystalline phase formation of CuBO₂ unaltered by composite formation with graphene. Raman spectroscopic studies were employed to confirm the presence of graphene. A morphological study with field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) suggested the proper wrapping of RGO sheets over CuBO₂ nanocubes. Moreover, the close proximity of lattice planes of CuBO₂ and RGO to each other was observed in high-resolution TEM studies that were correlated with the Raman spectroscopic studies. Finally, the samples were characterized to study the field emission (FE) properties of the same using a laboratory-made high-vacuum field-emission setup. Finite-element-based theoretical simulation studies were carried out to explain and compare the field emission properties with the experimental results. The FE properties of the composite samples were found to be tuned by the nature of wrapping the RGO sheets over the CuBO₂ nanocubes, which was typically dependent upon the spiky morphology of the nanocubes.