Abstract

The control of the structure and preferential orientation of molecular organic thin films might be achieved by the selection of suitable substrates that, in general, have to be designed. Langmuir–Blodgett (LB) and self-assembled monolayers (SAMs) films are good candidates as substrates due to the chemical versatility of their surfaces. We illustrate an example of the selection of either of the two energetically most probable preferential orientations of polycrystalline neutral tetramethyltetraselenafulvalene (TMTSF) thin films by the choice of different substrates. The films (thickness ∼1 µm), obtained by sublimation of TMTSF microcrystals in high vacuum (∼10⁻⁶ mbar), are dominated by (0 −2 1)- and (100)-oriented microcrystals when using KBr (100) and methyl-terminated films, respectively.