First-principles study on CVD growth mechanism of 2D NbC on Cu (111) surface

Two-dimensional (2D) niobium carbide is a member of the 2D transition metal carbide family. It exhibits properties that are beneficial for various applications. However, fabricating a 2D NbC single crystal with a specific orientation is extremely challenging and its epitaxial growth mechanism is not yet understood. A sys-tematic study on the chemical vapour deposition of 2D NbC on the Cu(1 1 1) substrate has been performed in this study using first-principles calculations. The nucleation sites of Nb, C atoms and NbCy (y = 1, 2 and 3) clusters on the Cu(1 1 1) surface and the dominant precursor during the initial growth of NbC were determined. The growth kinetics and the epitaxial growth mechanism of a 2D NbC(1 1 1) single crystal on Cu(1 1 1) were elucidated. The results of this study can serve as a solid theoretical basis for experiments on 2D NbC and other transition metal carbides.