Direct Measurements of Island Growth and Step-Edge Barriers in Colloidal Epitaxy
Ganapathy, R.; Buckley, M.R.; Gerbode, S.J.; Cohen, I.
Epitaxial growth, a bottom-up self-assembly process for creating surface nano-and microstructures, has been extensively studied in the context of atoms. This process, however, is also a promising route to self-assembly of nanometer- and micrometer-scale particles into microstructures that have numerous technological applications. To determine whether atomic epitaxial growth laws are applicable to the epitaxy of larger particles with attractive interactions, we investigated the nucleation and growth dynamics of colloidal crystal films with single-particle resolution. We show quantitatively that colloidal epitaxy obeys the same two-dimensional island nucleation and growth laws that govern atomic epitaxy. However, we found that in colloidal epitaxy, step-edge and corner barriers that are responsible for film morphology have a diffusive origin. This diffusive mechanism suggests new routes toward controlling film morphology during epitaxy.
We thank L. Ristroph, J. Savage, T. Arias, J. Machta, and A. Woll for useful discussions. We would like to especially thank J. Sethna for helping us set up the numerical calculations for residence times. This research was supported by grants from the NSF Division of Materials Research, the Cornell NanoScale Science and Technology Facility, and in part by award no. KUS-C1-018-02 from King Abdullah University of Science and Technology (KAUST).
AMER ASSOC ADVANCEMENT SCIENCE, 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
THIN-FILM GROWTH; NUCLEATION; CRYSTALS; NANOSTRUCTURES; DIFFUSION; PARTICLES; DYNAMICS; SURFACES; VIEW
Previously Published As
SCIENCE, 327 (5964),445-448, JAN 22 2010