We have investigated the growth process of benzodithiophene (BDT)-dimer films deposited on similar to 1.1-monolayer-thick pentacene layers used as crystallinity control layers (CCLs). It has been found that the BDT-dimer film shows, on their initial stage, two-dimensional growth with the 2nd-layer pentacene islands of the CCLs working as the growth nuclei. Thus, we considerably reduced the density of the 2nd-layer pentacene islands of the CCLs by lowering their growth rate because the density is determined by the migration length of the pentacene molecules on the surfaces. As a result, we obtained BDT-dimer films consists of enlarged grains, and lowered the channel resistance of the pentacene-CCL/BDT-dimer FETs. (c) 2013 Elsevier B.V. All rights reserved.