| 초록 |
A new series of copolymers with high brightness and luminance efficiency were synthesized using the Gilch polymerization method, and their electro-optical properties were investigated. The weight-average molecular weights (Mw) and polydispersities of the synthesized poly(9,9-dioctylfluorenyl-2,7-vinylene) [poly(FV)], poly[2-(3-dimethyldodecyl silylphenyl)-1,4-phenylenevinylene] [poly(m-SiPhPV)] and poly[9,9-di-n-octylfluorenyl-2,7-vinylene]-co-(2-(3-dimethyldodecylsilylphenyl)-1,4-phenylene vinylene)] [poly(FV-co-m-SiPhPV)] were found to be in the ranges of 8.7-32.6 x 104 and 2.3-5.4, respectively. It was found that the electro-optical properties of the copolymers could be adjusted by controlling the feed ratios of the comonomers. Thin films of poly(FV), poly(m-SiPhPV), and poly(FV-co-m-SiPhPV) were foumd to exhibit photoluminescence quantum yields between 21 and 42 %, which are higher than those of MEH-PPV. Light-emitting diodes were fabricated in ITO/PEDOT/light-emitting polymer/cathode configurations using either double layer (LiF/Al) or triple layer (Alq3/LiF/Al) cathode structures. The performance of the PLEDs with triple layer cathodes was found to be better than that of the PLEDs with double layer cathodes. The turn-on voltages of the PLEDs were in the range of 4.5-6.0 V, with maximum brightness and luminance efficiency up to 9691 cd/m2 at 16 V and 3.27 cd/A at 13V, respectively. |
