Orientation of azobenzene chromophore incorporated into metal halide-based layered perovskite having organic-inorganic superlattice structure

Thin films of cadmium bromide-based layered perovskites with a superlattice structure consisting of an inorganic layer of corner-sharing CdBr6 octahedra and an organic layer of azobenzene-linked ammonium molecules were prepared by spin-coating from dimethylformamide solutions in which CdBr2 and azobenzene-linked ammonium bromides were dissolved. In the layered perovskite films, azobenzene chromophore was demonstrated to have a tendency to be oriented nearly normal to the film plane from the linear dichroism measurement. In addition, the relationship between orientational order (order parameter and tilt angle) of azobenzene chromophore and molecular structure of the azobenzene-linked ammonium molecules was investigated. (C) 2001 Elsevier Science B.V. All rights reserved.