title: Controlling the orientations of h-BN during growth on transition metals by chemical vapor deposition.
abstract: Hexagonal boron nitride (h-BN) is crucial for many applications, and its synthesis over a large area with high quality is strongly desired. A promising approach to synthesize h-BN is chemical vapor deposition on transition metal catalysts, in which the alignments of BN clusters in the initial growth determine both the types and the amounts of defects in h-BN. In the search for a better catalyst, we systematically studied the interactions between h-BN clusters and various metal surfaces. Our results show that the clusters on nearly all catalyst surfaces, no matter whether the (111) facets of face-centered cubic (FCC) metals or the (0001) facets of hexagonal close packed (HCP) metals, have two local minima with opposite orientations. During the initial growth, h-BN clusters adopt the energy-favored sites, whose registry is well preserved upon further growth owing to the strong interaction between the edge atoms of h-BN and the underlying substrates. On FCC(111), the h-BN domains are always aligned in parallel orientations, while on HCP(0001) they are parallel on the same terrace and anti-parallel on neighboring terraces. Beyond this, on the (111) surfaces of Ir and Rh, the BhNtconfiguration is much more energy favorable than BfNt, where, the subscripts h, t, and f represent the adsorption sites, hcp, top and fcc, respectively. Thus, Ir(111) and Rh(111) might promote the growth of h-BN domains with the same alignments, which will greatly improve the quality of h-BN by reducing the possibility of formation of grain boundaries.
authors.affiliation: School of Materials Science and Engineering, Henan Polytechnic University, Henan 454003, China and Beijing Computational Science Research Center, Beijing 100084, China and College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China.
authors.forename: Ruiqi
authors.identifier: http://orcid.org/0000-0002-1692-3753
authors.initials: R
authors.lastname: Zhao
authors.affiliation: College of Chemistry and Chemical Engineering, Henan Polytechnic University, Henan 454003, China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Zhao
authors.affiliation: College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China.
authors.forename: Zhirong
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Beijing Computational Science Research Center, Beijing 100084, China and Institute of Textiles and Clothing, Hong Kong Polytechnic University, Kowloon, Hong Kong, China. feng.ding@polyu.edu.hk.
authors.forename: Feng
authors.identifier: http://orcid.org/0000-0001-9153-9279
authors.initials: F
authors.lastname: Ding
authors.affiliation: College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China.
authors.forename: Zhongfan
authors.initials: Z
authors.lastname: Liu