Abstract
We synthesized new hole-transporting material, N,N′-diethyl-3,3′-bicarbazyl (E-Cvz-2), 9,9′-diethyl-6-(9-ethyl-carbazol-3-yl)-3,3′-bicarbazole (E-Cvz-3), 6-(9,9′-diethyl-3,3′-bicarbazol-6-yl)-9,9′-diethyl-3,3′-bicarbazole(E-Cvz-4A) and 9-ethyl-6-(9-ethyl-3,9′-bicarbazol-6-yl)-3,9′-bicarbazole (E-Cvz-4B).
EL luminance efficiencies of E-Cvz-2, E-Cvz-3, E-Cvz-4A and E-Cvz-4B devices were found to be 4.77, 5.68, 4.27 and 4.64 cd/A, respectively, when synthesized materials are using as a HTL material. The luminance efficiency of E-Cvz-3 is 25% higher than that of NPB, a commercialized HTL material used as a reference in this study.
This work was supported by Small and Medium Business Administration (SMBA). The authors thank SMBA for financial support 2007–2008. This study was supported by a grant from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Commerce, Industry and Energy, Republic of Korea.