LAUSR

A novel cross-linkable electron transport material, 1,3,5-tris(5-(4-vinylphenyl)pyridin-3-yl)benzene (TV-TmPY), for solution-processing as well as a small molecule, 1,3,5-tris(5-phenylpyridin-3-yl)benzene (TmPY), for vacuum deposition were designed and synthesized for OLEDs. TV-TmPY and TmPY with identical core structures are fully characterized to systematically investigate the impact of solution processing and vacuum deposition on the performance of phosphorescent OLEDs. Over 90% EQE (external quantum efficiency) was achieved for the solution-processed TV-TmPY-based device compared to that of the vacuum-deposited TmPY at a luminance of 1000 cd m–2. An EQE deviation of 0.7% was observed ranging from 100 to 1000 cd m–2 with TV-TmPY, which is the smallest value to date for solution-processed OLEDs, and over 12% EQEs were achieved for the trilayered solution-processed green and blue phosphorescent OLEDs.