Supramolecular assembly strategies using alternate adsorption of polyelectrolytes: applications in PLED and LC display devices

We present work on the modification, processing, and analysis of ultrathin films for display devices primarily using the supramolecular assembly strategy. This involves the use of various molecular assembly techniques (organic, polymer, metal) in which layer order and functionality is achieved at defined length scales approaching that of ultrathin films (a few to several hundred nm thicknesses). The use of alternate polyelectrolyte deposition (APD) is primarily investigated in ultrathin films that have significance in the fabrication of display devices. The first application involves modifying a polymer light emitting diode (PLED) device fabricated using the ITO/MEH-PPV/Ca protocol with polyaniline derivatives. The second is the use of the 'command layer' amplification concept and photo-induced alignment using polarized light with ultrathin films of azo dye/polyelectrolytes in a hybrid liquid crystal (LC) cell configuration. Both strategies rely on the use of surface sensitive spectroscopic and microscopic techniques to correlate device performance with layer ordering at the molecular level. The concept of functional ultrathin layers for device fabrication and modification is emphasized.