Organic-Inorganic Hetero Nanosystems as an Approach to Molecular Optoelectronics

Abstract

A concept of organic-inorganic hetero nanosystems has been proposed as an approach to molecular optoelectronics. The direct use of the optical function of an individual organic molecule in a solid state is anticipated through the electronic function of inorganic materials. Basic information on the formation of hetero nanostructures by vacuum thin film technology was discussed. Various types of organic-inorganic hetero nanostructures consisting of copperphthalocyanine (CuPc) molecular crystals and metal oxides of TiOx and SiO2 were fabricated by evaporation and reactive evaporation techniques. Cross sectional transmission electron microscopy (TEM) directly revealed that the thickness of the mixing layer at the ceramics interface on a CuPc molecular crystal is at most a monolayer of CuPc in superlattice structures. The formation of nanoboxes of CuPc molecular crystal in a ceramic matrix which had been fabricated using the multilayer technique, was confirmed by observations of in-plane TEM and atomic force microscopy. Optoelectronic functions in organic-inorganic hetero nanosystems were discussed from the viewpoints of carrier generation at the interface, size effects, and molecular orientation.