TY - JOUR
T1 - Host copolymers containing pendant carbazole and oxadiazole groups
T2 - Synthesis, characterization and optoelectronic applications for efficient green phosphorescent OLEDs
AU - Yeh, Kun Ming
AU - Lee, Chih Cheng
AU - Chen, Yun
PY - 2008/8/1
Y1 - 2008/8/1
N2 - Vinyl copolymers (PCOn), containing pendant carbazole and aromatic 1,3,4-oxadiazole attached with dodecyloxy group, were prepared from their corresponding precursor poly(9-vinyl carbazole-co-4-vinylbenzyl chloride) (PCBn) by the Williamson condensation (n: mole% of 4-vinylbenzyl chloride). These copolymers were used as host materials for green phosphorescent light-emitting diodes after blending 4 wt % of Ir(ppy)3. PL spectra of the PCOn films showed the formation of excimer or exciplex. The phosphorescent EL devices were fabricated with a configuration of ITO/PEDOT:PSS/host copolymers:Ir(ppy) 3/BCP/Ca/Al. The PL and EL spectra of the blends [PCOn:Ir(ppy) 3] revealed dominant green emission at 517 nm attributed to Ir(ppy)3 due to efficient energy transfer from the host to Ir(ppy)3. Efficient green phosphorescent OLEDs was obtained when employing copolymer PCO16 as the host and Ir(ppy)s as the guest. The maximal luminance efficiency and the maximal luminance of this device were 17.9 cd/A and 19,903 cd/m2, respectively. After doped with Ir(ppy) 3, the morphology of the films, both controlled PCP20 and PCO20 with attached dodecyloxy groups, were investigated by tapping-mode AFM and FE-SEM. The film of PCO20 exhibited uniform, featureless image and showed much better device performance than PCP20, which have been attributed to good compatibility of PCO20 with Ir(ppy)3.
AB - Vinyl copolymers (PCOn), containing pendant carbazole and aromatic 1,3,4-oxadiazole attached with dodecyloxy group, were prepared from their corresponding precursor poly(9-vinyl carbazole-co-4-vinylbenzyl chloride) (PCBn) by the Williamson condensation (n: mole% of 4-vinylbenzyl chloride). These copolymers were used as host materials for green phosphorescent light-emitting diodes after blending 4 wt % of Ir(ppy)3. PL spectra of the PCOn films showed the formation of excimer or exciplex. The phosphorescent EL devices were fabricated with a configuration of ITO/PEDOT:PSS/host copolymers:Ir(ppy) 3/BCP/Ca/Al. The PL and EL spectra of the blends [PCOn:Ir(ppy) 3] revealed dominant green emission at 517 nm attributed to Ir(ppy)3 due to efficient energy transfer from the host to Ir(ppy)3. Efficient green phosphorescent OLEDs was obtained when employing copolymer PCO16 as the host and Ir(ppy)s as the guest. The maximal luminance efficiency and the maximal luminance of this device were 17.9 cd/A and 19,903 cd/m2, respectively. After doped with Ir(ppy) 3, the morphology of the films, both controlled PCP20 and PCO20 with attached dodecyloxy groups, were investigated by tapping-mode AFM and FE-SEM. The film of PCO20 exhibited uniform, featureless image and showed much better device performance than PCP20, which have been attributed to good compatibility of PCO20 with Ir(ppy)3.
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U2 - 10.1002/pola.22846
DO - 10.1002/pola.22846
M3 - Article
AN - SCOPUS:47549102424
SN - 0887-624X
VL - 46
SP - 5180
EP - 5193
JO - Journal of Polymer Science, Part A: Polymer Chemistry
JF - Journal of Polymer Science, Part A: Polymer Chemistry
IS - 15
ER -