title: Preparation of ordered films containing a phenylene ethynylene oligomer by the Langmuir-Blodgett technique.
abstract: This paper reports the fabrication and characterization of Langmuir and Langmuir-Blodgett (LB) films incorporating an oligo(phenylene-ethynylene) (OPE) derivative, namely, 4-[4-(4-hexyloxyphenylethynyl)-phenylethynyl]-benzoic acid (HBPEB). Conditions appropriate for deposition of monolayers of HBPEB at the air-water interface have been established and the resulting Langmuir films characterized by a combination of surface pressure and surface potential versus area per molecule isotherms, Brewster angle microscopy, and ultraviolet reflection spectroscopy. The Langmuir films are readily transferred onto solid substrates, and one-layer LB films transferred at several surface pressures onto mica substrates have been analyzed by means of atomic force microscopy, from which it can be concluded that 14 mN/m is an optimum surface pressure of transference, giving well-ordered homogeneous films without three-dimensional defects and a low surface roughness. The optical and emissive properties of the LB films have been determined with significant blue-shifted absorption spectra indicating formation of two-dimensional H aggregates and a Stokes shift illustrating the effects of the solid-like environment on the molecular chromophore.
authors.affiliation: Departamento de Química OrgAnica-Química Física, Area de Química Física, Facultad de Ciencias, Universidad de Zaragoza, Zaragoza, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Villares
authors.forename: Donocadh P
authors.initials: DP
authors.lastname: Lydon
authors.forename: Laurent
authors.initials: L
authors.lastname: Porrès
authors.forename: Andrew
authors.initials: A
authors.lastname: Beeby
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Low
authors.forename: Pilar
authors.initials: P
authors.lastname: Cea
authors.forename: Fèlix M
authors.initials: FM
authors.lastname: Royo