Wafer-Scale Single Crystal Hexagonal Boron Nitride Layers Grown by Submicron-Spacing Vapor Deposition

The direct growth of wafer-scale single crystal two-dimensional (2D) hexagonal boron nitride (h-BN) layer with a controllable thickness is highly desirable for 2D-material-based device applications. Here, for the first time, a facile submicron-spacing vapor deposition (SSVD) method is reported to achieve 2-inch single crystal h-BN layers with controllable thickness from monolayer to tens of nanometers on the dielectric sapphire substrates using a boron film as the solid source. In the SSVD growth, the boron film is fully covered by the same-sized sapphire substrate with a submicron spacing, leading to an efficient vapor diffusion transport. The epitaxial h-BN layer exhibits extremely high crystalline quality, as demonstrated by both a sharp Raman E-2g vibration mode (12 cm(-1)) and a narrow X-ray rocking curve (0.10 degrees). Furthermore, a deep ultraviolet photodetector and a ZrS2/h-BN heterostructure fabricated from the h-BN layer demonstrate its fascinating properties and potential applications. This facile method to synthesize wafer-scale single crystal h-BN layers with controllable thickness paves the way to future 2D semiconductor-based electronics and optoelectronics.

Automated summary

A facile submicron-spacing vapor deposition (SSVD) method is reported for growing wafer-scale single crystal h-BN layers with controllable thickness on sapphire substrates. The epitaxial h-BN layer shows high crystalline quality and is demonstrated to have potential applications in a deep ultraviolet photodetector and a ZrS2/h-BN heterostructure. This method provides a promising path towards future 2D semiconductor-based electronics and optoelectronics.