Highly efficient pure blue electroluminescence from 1,4-bis2-(3-N-ethylcarbazoryl)vinylbenzene

摘要

An efficient blue organic light-emitting diode with 1,4-bis2-(3-N-ethylcarbazoryl)vinylbenzene doped into 4,4′-N,N′-dicarbazole-biphyenyl is reported. Maximum luminance and external quantum efficiency are 8500 cd/m~(2) and 2.6. CIE-1931 coordinates are x=0.15, y=0.16. The device performance was further improved by introducing bis(2-methyl-8-quinolinato)4-phenylphenolate aluminum to assist electron injection. The maximum luminance and quantum efficiency reached 11000 cd/m~(2) and 3.3, respectively. Foster energy transfer and especially a carrier trapping mechanism are considered to dominate in the process of electroluminescence.