Capillary effects in guided crystallization of organic thin films

Abstract

Recently, it has been demonstrated that solvent-vapor-induced crystallization of triethylsilylethynyl anthradithiophene (TES ADT) thin films can be directed on millimeter length scales along arbitrary paths by controlling local crystal growth rates via pre-patterning the substrate. Here, we study the influence of capillary effects on crystallization along such channels. We first derive an analytical expression for the steady-state growth front velocity as a function of channel width and validate it with numerical simulations. Then, using data from TES ADT guided crystallization experiments, we extract a characteristic channel width, which provides the smallest feature size that can be obtained by this technique.