| Research Abstract |
Organic thin films have high potential for next generation photoelectronic and photonic materials.
Their physical properties heavily depend oh the molecular orientation in the film In this project, we aim to fabrication and characterization of orientation-controlled organic/inorganic and organic/organic hybrid films.
In the case of planar molecules such as quinacridone(QD) compounds, QD molecules grew epitaxially on a cleaved surface of alkali halide. The absorption property of QD films was depended on the molecular orientation. When QD molecules oriented parallel to the substrate surface, the intermolecular charge transfer was contributed effectively to the absorption intensity in the short wavelength region. We also investigated the structure and optical properties of sigma- and pi-conjugated oligomers such as oligodimethylsilane (ODMS) and distyrylbenzane derivatives (trimer of poly (p-phenylene vinylene):PPV) vapor-deposited on uniaxially oriented polydimethylsilane (PDMS) and PPV films. ODMS and DSBs grew epitaxially on the PDMS and PPV layers. The ODMS/PDMS and DSBs/PPV double layers indicated the remarkable anisotropic feature in absorption and emission properties. The dichroic ratio of absorption and emission intensities (I// / IL) were about 15 and 10, respectively. We succeeded in preparation of polarized emitting oligomer films as novel photonic materials.
In the case of the aggregate formation of merocyanine (MD) dyes in thin film., on the other hand, amorphous films had high potential. We also found that the - structure of,aggregate was depended on the alkyl chain lengths introduced at the benzothiazol ring. MD-2, -5 and -6 films, which the numbers indicate the number of carbon atoms in the alkyl chain, from H-aggregates, and MD-10 and amorphous MD-18 form J-aggregates. These films had high potential for optical memory.
|
