▎ 摘　　要

Monolayer hexagonal boron-nitrogen-carbon (h-BNC) is considered a prominent candidate for the next generation of semiconductor electronic devices. Nevertheless, experimental evidence of h-BNC formation is limited, including a detailed study of its morphological and electronic properties. Here, successful growth of h-BNC from an unexplored single molecular precursor (hexamethyl borazine, C6H18B3N3) using a conventional CVD approach on Ir(111) is reported. The conformation structure of the monolayer and its correlation with the local electronic properties are discussed based on scanning tunneling microscopy/spectroscopy (STM/STS) and X-ray photoelectron spectroscopy (XPS) results. The results show an h-BNC structure that can be described as BN-doped graphene since the moire ' lattice parameter is preserved along with the alloy. This BN-doped cluster, renamed as h-BN "nanodonuts" according to the electronic density exhibited in STM images, have a tendency to place specific positions within the moire superstructure, and it is constituted by at least (BN)(8) units arranged in a 6-fold BN rings conformation, as evidenced by simulation of STM images based on density functional theory (DFT). For a BN concentration of about 17%, a band gap between 1.4 and 1.6 eV was determined. The versatility of the novel molecular precursor is proven by the growth of a high-quality h-BN monolayer on Rh(111).