Assembly of two-dimensional (2D) molecular arrays on surfaces has been extensively investigated to understand the structural relationship between substrates and films, but little attention has been given to the mechanism by which they nucleate. Using peptides selected for their binding affinity to MoS2, we investigated nucleation of 2D arrays by molecularly-resolved in situ atomic force microscopy and compared our results to molecular dynamics simulations. The arrays assembled one row at a time, and the nuclei were ordered from the earliest stages and formed without a free energy barrier or a critical size. The results verify long-standing but unproven predictions of classical nucleation theory in one-dimension while revealing key interactions underlying 2D assembly.
Published: May 11, 2022
Citation
Chen J., E. Zhu, J. Liu, S. Zhang, Z. Lin, X. Duan, and H. Heinz, et al. 2018.Building Two-Dimensional Materials One Row at a Time: Avoiding the Nucleation Barrier.Science 362, no. 6419:1135-1139.PNNL-SA-139351.doi:10.1126/science.aau4146