A Theory of Growing Crystalline Nanorods - Mode I

Abstract

Nanorods grow in two modes through physical vapor deposition (PVD). In mode I, monolayer surface steps dictate the diameter of nanorods. In mode II, multiple-layer surface steps dictate the diameter, which is the smallest possible under physical vapor deposition [X. B. Niu et al., Phys. Rev. Lett 110, 136102 (2013) and F. Du & H. C. Huang, Phys. Rev. Materials. 1, 033401 (2017)]. This paper reports closed-form theories of terrace lengths and nanorod diameter during the growth in mode I, as a function of deposition conditions. The accompanying lattice kinetic Monte Carlo simulations verify the theories. This study reveals that (1) quasi-steady growth exists for each set of nanorod growth condition, (2) the characteristic length scales, including terrace lengths and nanorod diameter at the quasi-steady state, depend on the deposition conditions - deposition rate F, substrate temperature T, and incidence angle .