1403934-61-1Relevant articles and documents
Polymers with alkyl main chain pendent biphenyl carbazole or triphenylamine unit as host for polymer light emitting diodes
Chuang, Ching-Nan,Chuang, Hsin-Jou,Chen, Szu-Hsien,Leung, Man-Kit,Hsieh, Kuo-Huang,Wang, Yu-Xun,Huang, Jau-Jiun
, p. 4983 - 4992,10 (2012/12/12)
The soluble styrene polymers, bearing dicarbazole, phenylcarbazole or phenyltriphenylamine side groups were investigated as a host material for green emitter in phosphorescent PLED devices. Those polymers were synthesized by free radical polymerization via azobisisobutyronitrile (AIBN) as initiator under 75 °C. All of the host materials exhibit high thermal stability with high decomposition (Td,5% weight loss > 398 °C) and glass transition temperatures (Tg > 172 °C). The HOMO (ca. -5.39 -5.69 eV) and LUMO (ca. -2.22 -2.41 eV) levels with the triplet energy of ca. 2.50-2.93 eV suggest that polymers are suitable for host materials for green emitter. The devices based on the emissive layers containing host materials doped with Ir(ppy)3 (4 wt%) display stable green emission with high device performances. The brightness and current efficiency reach 15,800 cd/m2 and 17.5 cd/A, respectively, at the optimum blending with 40 wt% 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazol (t-PBD). Furthermore, the device performance reached higher brightness (23,400 cd/m2) and current efficiency (12.3 cd/A) when mixture with 2,4,6-triphenyl-1,3,5-triazine (TRZ) and t-PBD.
