Temperature-dependent polarization in LB films of a stilbazole complex of iridium(I)†

Abstract

The pyroelectric effect occurs in non-centrosymmetric, polar crystals and thin films whose spontaneous polarization changes as a function of temperature. In this paper, we report on a new organo-iridium complex which exhibits the pyroelectric effect. The alternate layer Langmuir-Blodgett deposition technique has been utilized to fabricate molecular assemblies which are polar at the macroscopic level. This technique facilitates the co-deposition onto solid substrates of monolayer films of two different materials (A and B) floating at an air-water interface. These monolayers are deposited alternately such that the resulting layer structure is of the ABABA form. This fabrication technology enables polar molecules to be organized into thin multi-lammellae assemblies which possess a macroscopic polarization. The pyroelectric coefficients of these films have been measured over a range of temperature. Several LB samples containing different numbers of iridium stilbazole monolayers have been examined showing that...