| Summary: | 碩士 === 國立高雄科技大學 === 化學工程與材料工程系 === 107 === In order to enhance light outcoupling efficiency of organic light emitting diodes (OLED) devices, we prepared three polyimides/silica composites with physical blending (A1-A3), covalent bonds (B1 and B2) and contain hollow nanoparticles (C1 and C2) characteristics. A series were prepared from the corresponding poly(amic acid) (PAA) and tetramethyl orthosilicate (TMOS) through thermal imidization and sol-gel process to form non-covalent bonding polyimide/silica composites. B series were prepared using 3-aminopropyltriethoxysilane (APTES) as coupling agent to form covalent bonding polyimide/silica composites. C series were prepared the covalent bonding polyimide/silica composites but the hollow silica nanoparticles.
Their optical, thermal, morphology were investigated. As the silica content increased the thermal properties increasing. In addition, the scattering properties increasing as well.
In addition, B series hybrid films showed better well-dispersed behavior than the A series under similar silica content through the SEM and DLS results. For C series, hollow nanoparticles had been prepared successfully through TEM image.
Finally, whole hybrid films were applied into OLED devices for optical measurement. Under similar silica content, the EQE performance was in the trend of C > B > A = pure polyimide = reference. In addition, the C2 based as light extraction film exhibited the best device performance than others, the current efficiency, power efficiency and EQE vale of this device was at 64.6 cd/A, 87.8 lm/w and 18.7 %. The EQE value reached 30 % that of a reference device (EQE = 14.4 %) fabricated and measured under similar conditions.
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