Summary: | 碩士 === 國立臺北科技大學 === 有機高分子研究所 === 90 === Organic conjugate materials have been successfully employed as emission layers in light emission devices recently. This research is aimed to synthesize chromophores containing an oxazole group. The effects of adding Cl and Br groups and connecting conjugate benzene into the structure on absorption and emission wavelengths were studied. We also discussed the possibility of applying this fluorescent material to the application of light-emitting diodes.
5-(4-Chloro-phenyl)-2-phenyl-oxazole 7, 2-Biphenyl-4-yl-5- (4’-chloro-phenyl) -oxazole 10, 2-Biphenyl-4-yl-5- (4’-Bromo-phenyl)-oxazole 15 were synthesized. These compounds showed intense fluorescence in solution, with band gaps between 3.31 ~ 3.49 eV. Since the LUMOs (Lowest Unoccupied Molecular Orbital) of these compounds are range from 2.56 to 2.78 eV, which is close to PBD’s (2-(4-biphenylyl) -5-(4-tert-butylphenyl)-1,3,4-oxadiazole) and is used as electron transport materials in this studies.
Single-layer polymer light-emitting devices are fabricated. PVK (poly (9- vinylcarbazole) is used as host-polymer. Nile red, Alq3 and NA-PPV are used as red, green, blue guest emiters. The light-emitter devices using compounds 10, 15 are found having lower turn-on voltages than PBD’s.
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