Abstract

Molecular aggregates are found abundantly in biological Systems where they function as energy funnels for sunlight to be used in photochemical reactions. Aggregates of dyes have also found technological application as sensitizers in the photographic industry; recently they have shown great promise for use in the field of optoelectronics. Studies of clusters in supersonic beams and the condensad phase have, therefore, attracted many spectrosco-pists of late. From a scientific point of view, understanding the physical properties of clusters of molecules or semiconductor partioles presents a great challenge in itself, as these species bridge the gap between a single molecule and a crystal. While in the past much of the work on aggregates was aimed at understanding the spectroscopy in terms of an excitonic mod- el, recently the focus has changed to comprehend the dynamic properties of aggregates.

© 1990 Optical Society of America