Growth of ordered thin films of tris(phenylquinoxaline) by organic molecular beam deposition

We report about organic molecular beam deposition of 1,3,5-tris[(6,7-dimeth yl-3-phenyl)quinoxaline-2-yl]benzene (Me-TPQ), a molecule with very promisi ng electron transporting properties. We have studied the evaporation condit ions in order to achieve control over the molecular order in the grown laye r. Especially the choice of the substrate has been found to be crucial. Typ e and degree of molecular order have been determined by X-ray diffraction m easurements. Absorption and photoluminescence spectra of the grown films ha ve been recorded in order to detect any influence of the molecular packing on the optical properties. We demonstrate that it is possible to grow order ed thin films of Me-TPQ by proper choice of the deposition conditions. (C) 2000 Elsevier Science B.V. All rights reserved.