Proximity effect of Optically Active h-BCN nanoflakes

Hexagonal BCN (h-BCN), an isoelectronic counterpart to graphene, exhibits chirality and offers the distinct advantage of optical activity in the vacuum ultraviolet (VUV) region, characterized by significantly higher wavelengths compared to graphene nanoflakes. h-BCN possesses a wide band gap and demonstrates desirable semiconducting properties. In this study, we employ Density Functional Theory (DFT) calculations to investigate the proximity effects of adsorbed h-BCN flakes on two-dimensional (2D) substrates. The chosen substrates encompass monolayers of 3d-transition metals and WSe₂, as well as a bilayer consisting of WSe₂/Ni. Notably, the hydrogen-terminated h-BCN nanoflakes retain their planar configuration following adsorption. We observe a robust interaction between h-BCN and fcc-based monolayers such as Ni(111), resulting in the closure of the optical band gap, while the adsorption energy on WSe₂ is notably weaker. In the latter case, the system maintains an approximate gap of 1.4 eV. Furthermore, we investigate the magnetism induced by the proximity of adsorbed chiral h-BCN molecules, as well as the chiral-induced spin selectivity within the proposed systems.