Fig. 4
From: Multistep nucleation and growth mechanisms of organic crystals from amorphous solid states
Experimental evolution of C7P-BTBT islands in comparison with kinetic Monte Carlo simulations. a, b Comparison between simulated (a) and experimental (b) time-dependent number evolutions of total islands. c, d Comparison between simulated (c) and experimental (d) time-dependent evolutions of the island area. e Schematic illustration showing the nanocluster-involved nonclassical nucleation mechanism. f–m High-resolution AFM images showing evidence of the spherical molecular cluster as mass transport carriers on the surface (green and red arrows marked two nanoclusters; white dash arrows marked the moving directions). Scale bar: 50 nm. n Single-crystal structure of C7P-BTBT showing the BTBT-core π–π interaction and phosphonate–phosphonate coupling (top), and the compressed π–π stacking distance of 3.42 Å (bottom). o Binding energy calculation results for CnP-BTBT (n = 3–11) (pink triangle), Cn-BTBT (n = 8 and 9) (blue triangle) and corresponding growth rates of CnP-BTBT (n = 5–11) (red circle). Error bars are standard deviations of migration speed measured from multiple samples
