Highly efficient multilayer organic pure-blue-light emitting diodes with substituted carbazoles compounds in the emitting layer

Bright-blue organic-light-emitting-diodes based on carbazolic-compounds as emitting layers or dopant in DPVBi matrix are described. Pure-blue light with CIE coordinates xy = (0.158;0.169) and external quantum efficiency as high as eta ext = 3.3% were obtained.