화학공학소재연구정보센터
Macromolecules, Vol.41, No.18, 6696-6702, 2008
Synthesis and characterization of highly branched poly(p-phenylenevinylene) derivatives for polymer light-emitting diode applications
A new series of green electroluminescencc polymers, poly[ (2-(3,7-dimethyloctyloxy)-3,5,6-trimethoxy-1,4-phenylenevinylene)] [poly(30C(1)OC(10)-PV)] and poly[2-(3-dimethyldodecylsilylphenyl)-l,4-phenylenevinylene] [poly(m-SiPh-PV)], and their corresponding copolymers, poly[2-{(3,7-dimethyloctyloxy)-3,5,6-trimethoxy-l,4-phenylenevinylenel-c o-(2-(3-dimethyldodecylsilylphenyl)-l,4-phenylenevinylene)] [poly(30C(1)OC(10)PV-co-m-SiPh-PV)], were synthesized through the Gilch polymerization method. The newly designed and highly branched molecular structures of the polymers, poly(30C(1)OC(10)-PV), poly(30C(1)OC(10)-PV-co-m-SiPh-PV) and poly(m-SiPh-PV), were completely soluble in common organic solvents and easily spin-coated onto an ITO-coated glass substrate to obtain high quality optical thin films. The weight-average molecular weight (M,) and polydispersity of poly(30C(1)OC(10)-PV) were 17.3 x 10(4) and 2.9, respectively, while those of poly(30C(1)OC(10)-PV-co-m-SiPh-PV) were in the range of (20.5-101.8) x 10(4) and 3.2-6.7, respectively. We fabricated polymer light-emitting diodes in ITO/PEDOT/emitting polymer/cathode configurations using either double-layer, LiF/Al. or triple-layer, LiF/Ca/Al, cathode structures. The emission maxima of the polymers, regardless of the copolymer compositions, were around 544-560 nm, which is a green color. The turn-on voltages of the EL polymers were in the range of 2.5-5.5 V, and the maximum brightness and luminance efficiency were 15.330 cd/m(2) at 10 V and 4.44 cd/A at 11 V, respectively.