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

Abstract

Abstract 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°). Furthermore, a deep ultraviolet photodetector and a ZrS 2 /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.