Published online by Cambridge University Press: 14 March 2011
We review here the recent characterization of vacuum deposited monolayer and multilayer thin films of two different perylenetetracarboxylic-dianydride-bisimides (Cn-PTCDI; n =4,5), quinacridone, and two new bis-(N-alkyl)-quinacridone dyes (DIQA and DEHQA) on single crystal alkali halides using a combination of in situ luminescence spectroscopies and ex situ tapping mode AFM. Flat lying monolayer structures are indicated for PTCDA on the (100) faces of NaCl, KCl and KBr, for C4-PTCDI on KCl, for C5-PTCDI on both KCl and KBr and for DIQA on both KCl and KBr. Coherent thin films, exhibiting layer-by-layer growth can be achieved for PTCDA on all substrates, for C4-PTCDI on KCl and for DIQA on both KBr and KCl. Both C4-PTCDI and DIQA appear to fulfill the requirements for dyes which exhibit layered growth with the molecular plane inclined at steep angles to the surface normal.