Organic Materials of Intermediate Dimensions for Optoelectronic Technologies

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

This research program has the goals of understanding how bringing conjugated organic chromophores into close proximity influences the optical and electronic properties of the ensemble and how molecular topology can be used to control the organization of molecules in the solid state. To achieve these goals the PI will synthesize model compounds and study their optical, electronic and morphological properties. Specific objectives during the grant period are: (1) The synthesis of structurally defined bichromophoric and multichromophoric molecules that are held together by the paracyclophane framework. The target molecules will have a rigid structure that precisely determines the distance, orientation and number of interacting units. (2) To combine spectroscopic studies with quantum mechanical analysis to build a cohesive view of photoexcitation in multichromophore paracyclophane structures. (3) The synthesis of a homologous series of aggregated chromophores with the intent of identifying the limit at which the electronic communication between individual units ceases to be important. These are truly organic nanomaterials in that their electronic description intermediate between those of individual chromophores and of bulk materials (i.e. crystals, polymer films). (4) The synthesis of organic molecules with geometries that discourage crystallization. Of interest is to examine how topology translates into bulk morphology. Materials of this type can be purified to a greater extent than polymer counterparts and therefore may offer advantages in situations where a small concentration of contaminants disproportionately affects charge migration in the solid. %%% The fundamental knowledge obtained through these studies will enable the engineering of organic materials for use in emerging optoelectronic technologies. This area of technology is likely to find widespread use in society. Specific examples include organic-based light emitting diodes for display applications, thin film transistors, solid state lasers, more efficient organic solar cells for energy generation and photodetectors. The issue of interchromophore delocalization is significant beyond the confines of materials design because it makes a profound impact in other areas of science, such the mechanism of photosynthesis and oxidative charge migration in double-stranded DNA.