Fabrication and Electrical Properties of Semi-Conductive h-BNC_x Thin Films

Two-dimensional thin films with graphene domains embedding in hexagonal boron nitride (h-BNC_x) has attractive application due to its tunable energy band gap. In this work, we report a one-step low pressure chemical vapor deposition method to fabricate large-area h-BNC_x films without introducing carbon source. The carbon in h-BNC_x derives from oil vapor of rotary pump, and it is well controlled by growing parameters, such as growing temperature, annealing time and growth time. It offers a method to fabricate h-BNC_x film with low carbon concentration (<20 at.% C). Electron energy loss spectrum shows that boron, nitride and carbon atoms are sp2 hybridized and assemble into atomic layers. X-ray photoelectron spectra characterization further reveals that the h-BNC_x has a hybridized structure with graphene domains embedding in h-BN layers. The intensity ratio of G-band and D-band in Raman spectra could be used to characterize the carbon content in h-BNC_x film qualitatively. The band gap and electrical properties of the h-BNC_x is tailored by the carbon concentration. The carrier mobility, resistivity perpendicular and parallel to the h-BNC_x film are 5.1×10^-2 cm².V^-1.s^-1, 55 k Ω cm and 12.6 MΩ cm for the samples with carbon concentration of 20.2 at.%, respectively.