Large-Area Synthesis and Fabrication of Few-Layer hBN/Monolayer RGO Heterostructures for Enhanced Contact Surface Potential

Hexagonal boron nitride (hBN) has a property similar to that of graphene, and it has become one of the most popular materials due to its flexible physical and chemical properties for a variety of applications, especially in nanoelectronics. Enhanced properties of hBN-based heterostructures are crucial for future electronic devices. In this work, a sheet-like hBN crystal was synthesized and transferred onto SiO2/Si substrate and reduced graphene oxide (RGO)/SiO2/Si substrate. Accordingly, the hBN and hBN/RGO films are investigated by optical microscopy, X-ray diffraction, high-resolution transmission electron microscopy, Raman spectroscopy, and atomic force microscopy. The thickness of a single hBN layer is approximately 0.4 nm. A few layers of hBN stacked in large areas are mostly observed in both hBN and the hBN/RGO films. By using Kelvin probe force microscopy, it was found that the hBN/RGO heterostructure has a contact surface potential higher than that of the hBN layer. The large-scale synthesis and fabrication of hBN/RGO films could be extended to fabricate other van der Waals heterostructures.